Toughened polylactic acid plastic and preparation method thereof
1. The toughened polylactic acid plastic is characterized in that: the polylactic acid plastic comprises polylactic acid resin, polyamide thermoplastic elastomer and processing aid; in the polylactic acid plastic, a polyamide thermoplastic elastomer phase is dispersed in an island-shaped polylactic acid resin matrix phase.
2. The toughened polylactic acid plastic as claimed in claim 1, wherein: the toughened polylactic acid plastic comprises the following raw materials in percentage by weight:
52 to 92.5 percent of polylactic resin
5 to 45 percent of polyamide thermoplastic elastomer
0.3 to 3 percent of processing aid
Preferably, the first and second liquid crystal materials are,
77-92.5 percent of polylactic resin
5 to 20 percent of polyamide thermoplastic elastomer
0.3 to 3 percent of processing aid.
3. The toughened polylactic acid plastic according to claim 1 or 2, wherein: the polylactic acid resin comprises polylactic acid and/or a polylactic acid copolymer.
4. The toughened polylactic acid plastic according to any one of claims 1 to 3, wherein: the crystallization temperature of the polyamide thermoplastic elastomer is higher than that of the polylactic acid resin;
preferably, the polyamide thermoplastic elastomer has a crystallization temperature of 120-130 ℃.
5. The toughened polylactic acid plastic according to any one of claims 1 to 4, wherein: the polyamide thermoplastic elastomer comprises polyamide hard segments and polyether soft segments;
preferably, the crystallization temperature of the polyamide hard segment is 120-130 ℃;
preferably, said polyamide thermoplastic elastomer comprises a block copolymer formed by hard polyamide blocks of the AABB type and soft polyether glycol blocks.
6. The toughened polylactic acid plastic as claimed in claim 5, wherein: the AABB type polyamide hard segment is even type polyamide, odd type polyamide, even odd type polyamide or odd type polyamide formed by using aliphatic diamine and aliphatic diacid;
preferably, the AABB type polyamide hard segment is one or more of polyamide 66, polyamide 610, polyamide 612, polyamide 614, polyamide 1010, polyamide 1012, polyamide 1014, polyamide 1013, polyamide 1214, polyamide 1212, polyamide 1213 or polyamide 1214;
preferably, the AABB type polyamide hard segment is one or more of polyamide 1010, polyamide 1012 or polyamide 1212.
7. The toughened polylactic acid plastic as claimed in claim 5 or 6, wherein: the polyether glycol soft segment is one or more of polyethylene glycol, polypropylene glycol or polytetramethylene ether glycol;
preferably, the polyether glycol soft segment is polyethylene glycol or polytetramethylene oxide ether glycol.
8. The toughened polylactic acid plastic as claimed in claim 1, wherein: the processing aid is at least one selected from an antioxidant, a dispersant, a colorant or a lubricant.
9. A method for preparing the toughened polylactic acid plastic as claimed in any one of claims 1 to 8, wherein: the preparation method comprises the following steps:
1) respectively drying the polylactic resin, the polyamide thermoplastic elastomer and the processing aid in drying equipment;
2) selecting the polylactic resin, the polyamide thermoplastic elastomer and the processing aid in the step 1) according to the proportion, and uniformly stirring to obtain a mixed material;
3) and 3) extruding and granulating the mixed material prepared in the step 2).
10. The method for preparing the toughened polylactic acid plastic as claimed in claim 9, wherein: in the step 3), the extrusion granulation is carried out in a double-screw extruder, and the extrusion conditions are as follows: the temperature of the feeding section is 150-160 ℃, the temperature of the compression section is 190-210 ℃, the temperature of the metering section is 190-210 ℃, and the temperature of the machine head is 200-210 ℃; screw rotation speed: 50 to 100 r/min.
Background
The application of plastic products is more and more extensive, but the plastic waste brought by the plastic products is continuously increased, and the adverse effect on the environment is more and more serious. Conventional plastic wasteThe waste is mainly treated by methods such as recovery, burying, incineration and the like, the treatment methods have low efficiency and large energy consumption, and toxic gas generated during incineration can cause secondary pollution. In recent years, the research and use of biodegradable plastics have become a hot spot in academia and industry. Biodegradable plastics are a class of plastics that are degraded by the action of microorganisms such as bacteria, fungi or algae that occur in nature. It has excellent use performance, can be completely decomposed by environmental microorganisms after being discarded, and finally is inorganic to enter carbon circulation in nature, thereby greatly reducing the pollution of plastic garbage to the ecological environment, and therefore, the development of biodegradable plastics has great prospect. Among them, polylactic acid (PLA) is often used in biodegradable plastics because of its good mechanical properties and biodegradability. The polylactic acid is prepared by artificially synthesizing crops such as corn and the like, and can be finally decomposed into CO in the environment2And H2The thermoplastic aliphatic polyester of O does not cause pollution and damage to the environment. Although polylactic acid has the above good characteristics, the application of polylactic acid as general plastic is limited, namely the practical application of polylactic acid is limited due to two defects of low crystallinity and poor toughness.
Both academia and industry have been exploring the use of various approaches to solve these two problems. For example, a nucleating agent is used to increase the crystallinity of polylactic acid and reduce the half-peak width of the crystallization peak; various elastomers are used for toughening of polylactic acid. For various elastomer toughening agents, a compatibility agent can be used for improving the compatibility of the elastomer and the polylactic acid, and the impact resistance of the blend is further improved. In summary, in order to overcome the above disadvantages of polylactic acid, it is necessary to modify polylactic acid with toughening and to add a nucleating agent to improve its machinability. There has been little research on the use of a toughening agent to achieve both toughening and nucleation.
There are several documents that use PA 12-based or PA 11-based polyether amide copolymers (PEBA) for toughening modification of polylactic acid. For example, canadian scientists use PA 11-based PEBA, model number PEBAX RENEW 35R35, to toughen and modify l-polylactic acid (PLLA), while using a copolymer containing glycidyl methacrylate as a phase compatibilizer, to increase the impact resistance of PLLA to 500J/m while maintaining its tensile strength at 50 MPa. However, the use of PA12 and PA11 as elastomers having a hard segment does not improve the crystallinity of polylactic acid, and does not improve the crystallinity of polylactic acid.
In addition to the technological advances reported in the above academic papers, the skilled artisan has also attempted to toughen polylactic acid using various elastomers or novel processing techniques.
Chinese patent CN102690506A introduces a method for toughening PLA by using long carbon chain polyamide, and the toughened PLA resin is obtained by blending and banburying the long carbon chain polyamide, polylactic resin and reactive compatibilizer on a double-screw extruder at 210 ℃. However, the long carbon chain polyamide does not contain ester bonds and ether bonds, the compatibility with PLA can be improved only by additionally using a phase compatibilizer, and the crystallinity of the polylactic acid resin is not improved by simply using the long carbon chain polyamide.
Chinese patent CN101333332A describes a method for toughening PLA by using an acrylate copolymer, and the method is characterized in that the acrylate copolymer, polylactic resin and antioxidant B215 are mixed and banburied at 180 ℃ on a rubber mixing roll to obtain the toughened polylactic resin, and the impact resistance of the toughened resin is improved by more than one time. However, the crystallinity of the polylactic acid resin is not improved by using the acrylate type toughening agent.
Chinese patent CN 103483788A describes a method for toughening PLA with ethylene-vinyl acetate copolymer, which is to blend and banbury the dried ethylene-vinyl acetate (EVA) copolymer, polylactic acid resin and Glycidyl Methacrylate (GMA) to obtain a blend, and obtain toughened resin by hot pressing treatment with a flat-plate vulcanizer. The method avoids the use of toxic compatibilizers such as dioctyl phthalate (DOP). The toughness and crystallization performance of the PLA/EVA/GMA modified material obtained by the method are improved. However, the use of GMA small molecules in plastic articles still carries the risk of migration contamination and the process of blending followed by press curing also suffers from process efficiency.
Chinese patent CN 104559097a describes a method of toughening PLA using polyester elastomers based on biolistic dibasic acid diols. The polyester elastomer takes lactic acid and itaconic acid containing unsaturated double bonds as raw materials. Itaconic acid provides double bonds that can further crosslink compatibilization, which results in better compatibility between the toughening agent and the PLA resin. Firstly, the polyester elastomer and PLA are blended, so that polyester elastomer particles are uniformly dispersed in a PLA base material, a small amount of peroxide or peroxyacid ester initiator can be added, and free radicals are generated at high temperature to initiate the crosslinking of double bonds on itaconic acid and active sites on other molecular chains. However, the free radical polymerization initiated by thermal oxygen is more difficult to control, the free radical residue also has the risk of migration and exudation in the using process of plastic parts, and the method cannot improve the crystallization property of the polylactic acid.
Chinese patent CN 106147162A introduces a method for toughening PLA by using POE, SEBS and EPDM elastomers, and the elastomer, polylactic resin, auxiliary agent and graft modifier are blended and extruded at the temperature of 180-205 ℃ to obtain toughened polylactic resin, which can obviously improve the toughness of the PLA resin. The graft modifier is one or more of maleic anhydride, glycidyl methacrylate and glycidyl isobutyrate, but the crystallinity of the polylactic resin is not improved by using the acrylate type toughening agent.
Chinese patent CN 105479707A introduces a polylactic resin with good mechanical properties by using a special processing method to regulate and control the crystallization morphology of polylactic acid. In the processing process, the polylactic acid melt is stretched and sheared in different directions to finally form a Shish-Kebab structure, so that the strength and the toughness of the polylactic acid are obviously improved.
Chinese patent CN105670252A introduces a method for toughening PLA by using a bio-based vulcanized polyester elastomer, and the elastomer, polylactic resin and an anti-hydrolysis agent are blended and extruded at the temperature of 180-205 ℃ to obtain toughened polylactic resin, so that the toughness of the PLA resin can be remarkably improved, and the whole blend can be completely degraded. However, the crystallinity of the polylactic acid resin is not improved by using the bio-based vulcanized polyester elastomer.
"modification study of polyamide elastomer toughening polylactic acid" [ zhangwei, weifa ] modification study of polyamide elastomer toughening polylactic acid [ J ] chinese plastics, 2012, 26 (7): 46-49A polyamide elastomer (copolymer of polyamide and polyoxyethylene, PAE) and polylactic acid (PLA) are selected to be melted and blended for toughening modification. The results show that: both the cold crystallization and melting peaks of the blended system decreased with increasing PAE elastomer content, indicating that the crystallinity of the PLA decreased due to the increase in PAE elastomer. The crystallinity of pure PLA is 30.9%, and as the PAE content increases to 20%, its crystallinity decreases to 20.8%. The reason is that certain interaction exists between the polyether part in the PAE elastomer molecule and the PLA molecule in the blending system, and the action limits the movement of the PLA molecule to a certain extent and reduces the crystallinity of the PLA molecule. In addition, because the PAE elastomer is amorphous at the temperature of more than 100 ℃, the crystallinity of the system is reduced along with the increase of the content of the PAE elastomer, and the reduction of the crystallinity also plays a toughening effect to a certain extent.
In conclusion, it is a difficult problem to be solved in the art how to improve the crystallization property and the crystallinity while toughening the glass. At present, the toughening and nucleating effects can not be achieved simultaneously by using one toughening agent.
The present invention has been made in view of this situation.
Disclosure of Invention
The invention aims to overcome the defects of the prior art and provide a toughened polylactic acid plastic and a preparation method thereof.
In order to solve the technical problems, the invention adopts the technical scheme that:
the invention provides toughened polylactic acid plastic, which comprises polylactic acid resin, a polyamide thermoplastic elastomer and a processing aid; in the polylactic acid plastic, a polyamide thermoplastic elastomer phase is in an island shape and is dispersed in a polylactic acid resin matrix phase.
In the scheme of the invention, the crystallization temperature of the used polyamide thermoplastic elastomer is higher than that of the polylactic acid, so that a good nucleation induction effect is provided, and the polylactic acid is toughened and the crystallinity is improved; wherein the distribution mode of the polyamide thermoplastic elastomer phase in the polylactic acid resin matrix phase is island phase distribution, the grain diameter of the island-shaped particles of the polyamide thermoplastic elastomer (PAE) is 1-3 μm, if the grain diameter exceeds the upper limit of the grain diameter range, the interaction between the toughening agent and the polylactic acid resin matrix is reduced, the strength of the polylactic acid plastic is reduced, if the grain diameter exceeds the lower limit of the grain diameter range, the toughening effect is not obvious, and the polyamide thermoplastic elastomer is easy to be subjected to segregation in the polylactic acid resin.
Further, the toughened polylactic acid plastic comprises the following raw materials in parts by weight:
52 to 92.5 percent of polylactic resin
5 to 45 percent of polyamide thermoplastic elastomer
0.3 to 3 percent of processing aid.
Further, the toughened polylactic acid plastic comprises the following raw materials in parts by weight:
77-92.5 percent of polylactic resin
5 to 20 percent of polyamide thermoplastic elastomer
0.3 to 3 percent of processing aid.
Further, the polylactic acid resin comprises polylactic acid and/or a polylactic acid copolymer.
Furthermore, the molecular weight of the polylactic resin is 5-30 ten thousand.
Further, the crystallization temperature of the polyamide thermoplastic elastomer is higher than that of the polylactic acid resin;
preferably, the polyamide thermoplastic elastomer has a crystallization temperature of 120-130 ℃.
In the present invention, the use of the polyamide thermoplastic elastomer can increase the crystallinity of polylactic acid (PLA) while toughening it.
Further, the polyamide thermoplastic elastomer contains polyamide hard segments and polyether soft segments;
in the invention, the polyamide thermoplastic elastomer has better structural regularity of the hard segment, and the crystallization temperature of the PA-based elastomer is higher and is just slightly higher than that of PLA between 120 ℃ and 130 ℃ on the premise of the same hard segment content, thereby playing a good nucleation induction role.
In the invention, the polyamide hard segment has higher melting point and higher crystallinity, so that the elastomer can keep better dimensional stability and thermal stability. The polyether segment is soft and has good low-temperature flexibility and impact resistance, so that the elasticity can have good elasticity.
Further, the polyamide thermoplastic elastomer comprises a block copolymer formed by AABB type polyamide hard blocks and polyether glycol soft blocks.
In the invention, the polyamide thermoplastic elastomer is prepared by using AABB type long carbon chain polyamide as a polymer hard segment, and the AABB type polyamide is prepared by condensation polymerization of bifunctional diacid and diamine, so that the molecular chain structure is higher in designability, and the arrangement of hydrogen bonds is more regular, so that the AABB type polyamide with good chain structure symmetry has higher crystallization temperature and stronger nucleation induction effect compared with AB type polyamide with the same carbon chain length; polyether is used as a block copolymer of a polymer soft segment, and the molar ratio and the type of the elastomer soft segment and the elastomer hard segment can be regulated and controlled, so that the controllability of the elasticity and the hardness of the thermoplastic elastomer material is realized.
Further, the AABB type polyamide hard segment is an even type polyamide, an odd-even type polyamide, an even-odd type polyamide or an odd type polyamide formed by using aliphatic diamine and aliphatic dibasic acid;
further, the AABB type polyamide hard segment is one or more of polyamide 66, polyamide 610, polyamide 612, polyamide 614, polyamide 1010, polyamide 1012, polyamide 1014, polyamide 1013, polyamide 1214, polyamide 1212, polyamide 1213 or polyamide 1214;
further, the AABB type polyamide hard segment is one or more of polyamide 1010, polyamide 1012 or polyamide 1212.
Further, the AABB type polyamide hard segment is polyamide 1012.
Further, the polyether glycol soft segment is one or more of polyethylene glycol, polypropylene glycol or polytetramethylene oxide ether glycol;
further, the polyether glycol soft segment is polyethylene glycol or polytetramethylene oxide ether glycol (PTMO).
Further, the polyether glycol soft segment is polytetramethylene oxide ether glycol (PTMO).
In particular, in the present invention, the polyamide thermoplastic elastomer is a block copolymer comprising polyamide 1012(PA1012) as a polymer hard segment and polytetramethylene oxide ether glycol (PTMO) as a polymer soft segment.
In the invention, the polyamide 1012(PA1012) -based elastomer is most preferable, because the structural regularity of the hard segment PA1012 is better, on the premise of the same hard segment content, the crystallization temperature of the PA 1012-based elastomer is higher, and is just slightly higher than the crystallization temperature of polylactic acid (PLA) between 120 ℃ and 130 ℃, so as to play a good nucleation induction role, for example, as shown in FIG. 1, a toughened polylactic acid system added with the PA1012 elastomer has a sharp crystallization peak near 110 ℃, and the half-peak width is narrower, and in FIG. 2, the cold crystallization phenomenon of PLA disappears, which shows the good nucleation induction role of the PA 1012-based elastomer.
Further, the processing aid is selected from at least one of an antioxidant, a dispersant, a colorant or a lubricant.
Preferably, the processing aid is selected from an antioxidant, and the antioxidant is an antioxidant 1098.
The invention also provides a preparation method of the toughened polylactic acid plastic, which comprises the following steps:
1) respectively drying the polylactic resin, the polyamide thermoplastic elastomer and the processing aid in drying equipment;
2) selecting the polylactic resin, the polyamide thermoplastic elastomer and the processing aid in the step 1) according to the proportion, and uniformly stirring to obtain a mixed material;
3) and 3) extruding and granulating the mixed material prepared in the step 2).
Preferably, in step 3), the extrusion granulation is performed in a twin-screw extruder under the following extrusion conditions: the temperature of the feeding section is 150-160 ℃, the temperature of the compression section is 190-210 ℃, the temperature of the metering section is 190-210 ℃, and the temperature of the machine head is 200-210 ℃; screw rotation speed: 50 to 100 r/min.
The preparation method specifically comprises the following steps:
1) respectively placing the polylactic acid resin, the polyamide thermoplastic elastomer and the processing aid in a vacuum oven at 80 ℃ in drying equipment for drying overnight;
2) selecting the polylactic resin, the polyamide thermoplastic elastomer and the processing aid in the step 1) according to a proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation to obtain the material. Wherein, the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 150-160 ℃, the temperature of the compression section is 190-210 ℃, the temperature of the metering section is 190-210 ℃, and the temperature of the machine head is 200-210 ℃; screw rotation speed: 50 to 100 r/min.
After adopting the technical scheme, compared with the prior art, the invention has the following beneficial effects:
the polyamide thermoplastic elastomer used in the invention has better structural regularity of the hard segment, and the crystallization temperature of the hard segment is higher and is just slightly higher than the crystallization temperature of polylactic acid at the temperature of 120-130 ℃ on the premise of the same hard segment content, thereby playing a good nucleation inducing role and achieving the technical purpose of toughening the polylactic acid and simultaneously improving the crystallinity of the polylactic acid.
The following describes embodiments of the present invention in further detail with reference to the accompanying drawings.
Drawings
The accompanying drawings, which are included to provide a further understanding of the invention, are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the invention without limiting the invention to the right. It is obvious that the drawings in the following description are only some embodiments, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
In the drawings:
FIG. 1 is a DSC characterization of example 1, example 2, example 3 blends and pure PLLA prepared with PLLA/PAE at different mixing ratios;
FIG. 2 is a DSC characterization of example 1, example 2, example 3 blends and pure PLLA prepared at different mixing ratios of PLLA/PAE: a second heating process;
FIG. 3 is a DSC characterization of PLLA with PAE, PAE blends of example 1, example 4, example 5 and pure PLLA prepared at an 85/14.7 mixing ratio;
FIG. 4 is a POM image at 180 ℃ of the sample of example 1;
FIG. 5 is a POM image of the sample of example 1 cooled from 180 ℃ to 105 ℃ at 10 ℃/min;
FIG. 6 is a POM image of the sample of example 1 cooled from 180 ℃ to 85 ℃ at 10 ℃/min;
FIG. 7 is a liquid nitrogen brittle section SEM image of example 1;
fig. 8 is an engineering stress-strain curve of example 1 and pure PLLA.
It should be noted that the drawings and the description are not intended to limit the scope of the inventive concept in any way, but to illustrate it by a person skilled in the art with reference to specific embodiments.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and the following embodiments are used for illustrating the present invention and are not intended to limit the scope of the present invention.
Example 1
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 85% of plake L130 type levorotatory polylactic acid (PLLA), 14.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the placo L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62;
the polyamide thermoplastic elastomer (PAE) is PA1012-PTMO copolymer composed of PA1012 hard segments and PTMO soft segments alternately, and can be used for preparing elastomers with different moduli and strengths by means of the relative contents of polyamide hard segments and polyether soft segments, and the preparation method refers to the technical scheme disclosed in patent application 201610069156.4, and the PA1012 hard segment relative content (W) of PAE elastomerPA) The content was 25%.
The preparation method of the toughened polylactic acid plastic comprises the following steps:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 150 ℃, the temperature of the compression section is 190 ℃, the temperature of the metering section is 190 ℃, and the temperature of the machine head is 200 ℃; screw rotation speed: 50r/min to obtain the product.
Example 2
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 90% of plake L130 type levorotatory polylactic acid (PLLA), 9.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the plakia L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62.
The polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard segments and PTMO soft segments which are alternately arranged, and the elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard segments and the polyether soft segments, and the specific preparation method refers to the technical scheme disclosed in the patent application 201610069156.4. PA1012 relative hard segment content (W) of PAE elastomerPA) The content was 25%.
The preparation method of this example is the same as that of example 1.
Example 3
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 92.5 percent of plake L130 type levorotatory polylactic acid (PLLA), 7.2 percent of polyamide thermoplastic elastomer (PAE) and 10980.3 percent of antioxidant;
wherein, the optical rotation of the plakia L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62.
The polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard segments and PTMO soft segments which are alternately arranged, and the elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard segments and the polyether soft segments, and the specific preparation method refers to the technical scheme disclosed in the patent application 201610069156.4. PA1012 relative hard segment content (W) of PAE elastomerPA) The content was 25%.
The preparation method of this example is the same as that of example 1.
Example 4
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 85% of plake L130 type levorotatory polylactic acid (PLLA), 14.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the plakia L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62.
The polyamide thermoplastic elastomer (PAE) is PA1012-PTMO copolymer composed of PA1012 hard segments and PTMO soft segments alternately, and can be used for preparing elastomers with different moduli and strengths by means of the relative contents of polyamide hard segments and polyether soft segments, and the preparation method refers to the technical scheme disclosed in patent application 201610069156.4, and the PA1012 hard segment relative content (W) of PAE elastomerPA) The content was 45%.
The preparation method of this example is the same as that of example 1.
Example 5
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 85% of plake L130 type levorotatory polylactic acid (PLLA), 14.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the plakia L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62.
The polyamide thermoplastic elastomer (PAE) is PA1012-PTMO copolymer composed of PA1012 hard segments and PTMO soft segments alternately, and can be used for preparing elastomers with different moduli and strengths by means of the relative contents of the polyamide hard segments and the polyether soft segments, and the specific preparation method refers to the technical scheme disclosed in patent application 201610069156.4, and the relative content of the PA1012 hard segments (W1012 hard segments) of PAEPA) It was 76%.
The preparation method of this example is the same as that of example 1.
Example 6
The components and the amounts of the components are the same as those of the embodiment 1, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 155 ℃, the temperature of the compression section is 200 ℃, the temperature of the metering section is 200 ℃, and the temperature of the machine head is 205 ℃; screw rotation speed: and (5) 75r/min to obtain the product.
Example 7
The components and the amounts of the components are the same as those of the embodiment 1, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 160 ℃, the temperature of the compression section is 210 ℃, the temperature of the metering section is 210 ℃ and the temperature of the machine head is 210 ℃; screw rotation speed: 100r/min, and obtaining the product.
Example 8
The components and the amounts of the components are the same as those of the embodiment 2, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 155 ℃, the temperature of the compression section is 200 ℃, the temperature of the metering section is 200 ℃, and the temperature of the machine head is 205 ℃; screw rotation speed: and (5) 75r/min to obtain the product.
Example 9
The components and the amounts of the components are the same as those of the embodiment 2, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 160 ℃, the temperature of the compression section is 210 ℃, the temperature of the metering section is 210 ℃ and the temperature of the machine head is 210 ℃; screw rotation speed: 100r/min, and obtaining the product.
Example 10
The ingredients and the amounts of the components in the present example are the same as those in example 3, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 155 ℃, the temperature of the compression section is 200 ℃, the temperature of the metering section is 200 ℃, and the temperature of the machine head is 205 ℃; screw rotation speed: and (5) 75r/min to obtain the product.
Example 11
The ingredients and the amounts of the components in the present example are the same as those in example 3, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 160 ℃, the temperature of the compression section is 210 ℃, the temperature of the metering section is 210 ℃ and the temperature of the machine head is 210 ℃; screw rotation speed: 100r/min, and obtaining the product.
Example 12
The components and the amounts of the components are the same as those of the embodiment 4, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 155 ℃, the temperature of the compression section is 200 ℃, the temperature of the metering section is 200 ℃, and the temperature of the machine head is 205 ℃; screw rotation speed: and (5) 75r/min to obtain the product.
Example 13
The components and the amounts of the components are the same as those of the embodiment 4, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 160 ℃, the temperature of the compression section is 210 ℃, the temperature of the metering section is 210 ℃ and the temperature of the machine head is 210 ℃; screw rotation speed: 100r/min, and obtaining the product.
Example 14
The ingredients and the amounts of the components in the example are the same as those in the example 5, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 155 ℃, the temperature of the compression section is 200 ℃, the temperature of the metering section is 200 ℃, and the temperature of the machine head is 205 ℃; screw rotation speed: and (5) 75r/min to obtain the product.
Example 15
The ingredients and the amounts of the components in the example are the same as those in the example 5, except that the preparation method comprises the following steps:
the preparation method of this example includes:
1) respectively placing the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in a vacuum oven at 80 ℃ to dry overnight in a drying device;
2) selecting the levorotatory polylactic acid (PLLA), the polyamide thermoplastic elastomer (PAE) and the antioxidant 1098 in the step 1) according to the proportion, and uniformly stirring in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 160 ℃, the temperature of the compression section is 210 ℃, the temperature of the metering section is 210 ℃ and the temperature of the machine head is 210 ℃; screw rotation speed: 100r/min, and obtaining the product.
Example 16
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 85% of plake L130 type levorotatory polylactic acid (PLLA), 14.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the placo L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62;
the polyamide thermoplastic elastomer (PAE) is a PA1010-PTMO copolymer consisting of PA1010 hard segments and PTMO soft segments alternately, and can be used for preparing elastomers with different moduli and strengths by the relative contents of the polyamide hard segments and the polyether soft segments, wherein the PA1010 hard segment relative content (W1010 hard segment relative content)PA) The content was 25%.
This example was prepared in the same manner as example 1.
Example 17
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 90% of plake L130 type levorotatory polylactic acid (PLLA), 9.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the placo L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62;
the polyamide thermoplastic elastomer (PAE) is a PA1010-PTMO copolymer consisting of PA1010 hard segments and PTMO soft segments alternately, and can be used for preparing elastomers with different moduli and strengths by the relative contents of the polyamide hard segments and the polyether soft segments, wherein the PA1010 hard segment relative content (W1010 hard segment relative content)PA) The content was 25%.
This example was prepared in the same manner as example 1.
Example 18
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 92.5 percent of plake L130 type levorotatory polylactic acid (PLLA), 7.2 percent of polyamide thermoplastic elastomer (PAE) and 10980.3 percent of antioxidant;
wherein, the optical rotation of the placo L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62;
the polyamide thermoplastic elastomer (PAE) is a PA1010-PTMO copolymer consisting of PA1010 hard segments and PTMO soft segments alternately, and can be used for preparing elastomers with different moduli and strengths by the relative contents of the polyamide hard segments and the polyether soft segments, wherein the PA1010 hard segment relative content (W1010 hard segment relative content)PA) The content was 25%.
This example was prepared in the same manner as example 1.
Example 19
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 85% of plake L130 type levorotatory polylactic acid (PLLA), 14.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the placo L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62;
the polyamide thermoplastic elastomer (PAE) is a PA1212-PTMO copolymer composed of PA1212 hard segments and PTMO soft segments alternately, and can prepare elastomers with different moduli and strengths by the relative contents of the polyamide hard segments and the polyether soft segments, and the relative content (W) of the PA1212 hard segmentsPA) The content was 25%.
This example was prepared in the same manner as example 1.
Example 20
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 90% of plake L130 type levorotatory polylactic acid (PLLA), 9.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the placo L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62;
the polyamide thermoplastic elastomer (PAE) is a PA1212-PTMO copolymer consisting of PA1212 hard segments and PTMO soft segments which are alternatively arranged, and can be prepared by polyamide hard segments and polyether soft segmentsRelative content of segments to prepare elastomers of different moduli and strengths, PA1212 relative content of hard segments (W)PA) The content was 25%.
This example was prepared in the same manner as example 1.
Example 21
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 92.5 percent of plake L130 type levorotatory polylactic acid (PLLA), 7.2 percent of polyamide thermoplastic elastomer (PAE) and 10980.3 percent of antioxidant;
wherein, the optical rotation of the placo L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62;
the polyamide thermoplastic elastomer (PAE) is a PA1212-PTMO copolymer composed of PA1212 hard segments and PTMO soft segments alternately, and can prepare elastomers with different moduli and strengths by the relative contents of the polyamide hard segments and the polyether soft segments, and the relative content (W) of the PA1212 hard segmentsPA) The content was 25%.
This example was prepared in the same manner as example 1.
Example 22
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the polyamide thermoplastic elastomer (PAE) is a PA66-PTMO copolymer consisting of PA66 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the PA66 hard block relative content (WPA) is 25%; the remaining raw materials and the preparation method were the same as in example 1.
Example 23
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the polyamide thermoplastic elastomer (PAE) is a PA1214-PTMO copolymer consisting of PA1214 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the relative content (WPA) of the PA1214 hard blocks is 25 percent; the remaining raw materials and the preparation method were the same as in example 1.
Example 24
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the polyamide thermoplastic elastomer (PAE) is a PA612-PTMO copolymer consisting of PA612 hard segments and PTMO soft segments alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard segments and the polyether soft segments, and the PA612 hard segment relative content (WPA) is 25%; the remaining raw materials and the preparation method were the same as in example 1.
Example 25
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 52% of plake L130 type L-polylactic acid (PLLA), 45% of polyamide thermoplastic elastomer (PAE) and 10983% of antioxidant; wherein, the polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the PA1012 hard block relative content (WPA) is 25%; the preparation method is the same as that of example 1.
Example 26
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 63.5 percent of plake L130 type levorotatory polylactic acid (PLLA), 35 percent of polyamide thermoplastic elastomer (PAE) and 10981.5 percent of antioxidant; wherein, the polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the PA1012 hard block relative content (WPA) is 25%; the preparation method is the same as that of example 1.
Example 27
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 77% of plake L130 type L-polylactic acid (PLLA), 20% of polyamide thermoplastic elastomer (PAE) and 10983% of antioxidant; wherein, the polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the PA1012 hard block relative content (WPA) is 25%; the preparation method is the same as that of example 1.
Example 28
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 85% of poly (D-lactic acid) (PDLA), 14.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant; wherein, the polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the PA1012 hard block relative content (WPA) is 25%; the preparation method is the same as that of example 1.
Example 29
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 90% of poly (D-lactic acid) (PDLA), 9.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant; wherein, the polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the PA1012 hard block relative content (WPA) is 25%; the preparation method is the same as that of example 1.
Example 30
In this example, the raw materials and the amounts shown in table 1 are used, specifically:
this example differs from example 1 in that: the raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 55% of polylactic acid copolymer, 42.5% of polyamide thermoplastic elastomer (PAE) and 10982.5% of antioxidant; wherein the polylactic acid copolymer is mainly formed by poly L-lactic acid or poly D-lactic acid, or is formed by mixing poly L-lactic acid and poly D-lactic acid; the polyamide thermoplastic elastomer (PAE) is a PA1012-PTMO copolymer consisting of PA1012 hard blocks and PTMO soft blocks alternately, elastomers with different moduli and strengths can be prepared by the relative contents of the polyamide hard blocks and the polyether soft blocks, and the PA1012 hard block relative content (WPA) is 25%; the preparation method is the same as that of example 1.
Comparative example 1
Comparative example 1 differs from example 1 in that: selection of the Polyamide thermoplastic elastomer (PAE) used in comparative example 1
The raw materials of the toughened polylactic acid plastic comprise the following components in percentage by weight: 85% of plake L130 type levorotatory polylactic acid (PLLA), 14.7% of polyamide thermoplastic elastomer (PAE) and 10980.3% of antioxidant;
wherein, the optical rotation of the plake L130 type levorotatory polylactic acid (PLLA) is more than 99 percent, the Mw is 155.0kg/mol, the Mn is 96kg/mol, and the PDI is 1.62.
Polyamide thermoplastic elastomer (PAE), PAE elastomerPurchased from Arkema, france. It contains polyamide part with weight average relative molecular mass of 530 and content of 22%, polyoxyethylene part with weight average relative molecular mass of 2000 and content of 78%, and has the structural formula shown as the following formula:
the preparation method comprises the following steps:
1) respectively adding levorotatory polylactic acid (PLLA) and L-polylactic acid (PLLA) in a drying device,The elastomer and the antioxidant 1098 are dried overnight in a vacuum oven at 80 ℃;
2) selecting the levorotatory polylactic acid (PLLA) obtained in the step 1) according to the proportion,The elastomer and the antioxidant 1098 are stirred uniformly in a stirring mixer at normal temperature to obtain a mixed material;
3) putting the mixed material prepared in the step 2) into a double-screw extruder for extrusion granulation, wherein the extrusion conditions in the extrusion granulation are as follows: the temperature of the feeding section is 150 ℃, the temperature of the compression section is 190 ℃, the temperature of the metering section is 190 ℃, and the temperature of the machine head is 200 ℃; screw rotation speed: 50r/min to obtain the product.
Table 1: blend ratio of PAE and PLLA
Experimental example 1
DSC measurements were performed on the samples obtained in examples 1-5, and the results are shown in FIGS. 1-3:
FIG. 1 is a DSC characterization of example 1, example 2, example 3 blends and pure PLLA prepared with PLLA/PAE at different mixing ratios: cooling crystallization process after eliminating heat history; wherein the abscissa is temperature and the ordinate is heat flow;
FIG. 2 is a DSC characterization of example 1, example 2, example 3 blends and pure PLLA prepared at different mixing ratios of PLLA/PAE: a second heating process; wherein the abscissa is temperature and the ordinate is heat flow;
FIG. 3 is a DSC characterization of example 1, example 4, example 5 blends and pure PLLA prepared with PLLA and PAE at an 85/14.7 mixing ratio: cooling crystallization process after eliminating heat history; wherein the abscissa is temperature and the ordinate is heat flow;
taking 3-5mg of sample, heating to 210 ℃ to eliminate heat history, and then carrying out non-isothermal crystallization experiment. The cooling and heating rates are both 10 ℃/min. As shown in FIGS. 1-2, pure PLLA has no distinct crystallization peak during cooling, and a glass transition peak appears at about 60 ℃. And the blend added with the PA1012-PTMO copolymer has a crystallization peak of PA1012 in the range of 135-170 ℃, and the enthalpy value of the crystallization peak is along with the WPAAnd increased (as shown in figure 3). Since the crystallization property of polyamide is far superior to that of polylactic acid, the same effect is obtained in all the examples. As the temperature was decreased, the PLLA starting material showed a crystallization peak in the range of 100-120 deg.C, and therefore, it was considered that PA1012 crystals had the ability to induce crystallization relative to PLLA. During the second heating, pure PLLA without added PEBA had a cold crystallization peak at 100-. The blends exhibited crystalline melting peaks in the 160-180 ℃ range, with the melting points of both the PLLA and PA1012 crystalline regions being in this range. The overlap of the two makes it impossible to calculate the melting enthalpy of the respective crystalline phases by curve integration.
Experimental example 2
POM image analysis was performed on the samples obtained in example 1, and the results are shown in FIGS. 4 to 6:
FIG. 4 is a POM image at 180 ℃ of the sample of example 1;
FIG. 5 is a POM image of the sample of example 1 cooled from 180 ℃ to 105 ℃ at 10 ℃/min;
FIG. 6 is a POM image of the sample of example 1 cooled from 180 ℃ to 85 ℃ at 10 ℃/min;
a sample of film was placed between two coverslips and then placed on a hot stage. Heating to 210 ℃ first eliminates the thermal history, and then cooling at a rate of 10 ℃/min. POM was used to observe the morphology of the melt without blending and the crystallization process throughout the process. As shown in fig. 4-5, at 180 ℃, both PAE and PLLA were in a molten state, and PAE was distributed in the form of droplets in PLLA, which were not compatible. As the temperature decreased to 105 ℃, tiny crystals began to appear on the POM image. As the temperature was further decreased, the crystallization rapidly increased, and as seen from the POM image at 85 ℃, there were a large number of fine grains (fig. 6), indicating that the presence of PAE can promote the crystallization of PLLA, which has an induced nucleation effect on PLLA.
Experimental example 3
SEM image analysis of the sample obtained in example 1 gave the following results as shown in FIG. 7:
figure 7 shows a liquid nitrogen brittle fracture surface SEM image of example 1.
As shown in FIG. 7, it is explained that the distribution of the polyamide thermoplastic elastomer phase in the polylactic acid resin matrix phase is an island phase distribution, the island-shaped particles of the polyamide thermoplastic elastomer (PAE) have a particle size of 1 to 3 μm, and if the particle size exceeds the upper limit of the above particle size range, the interaction between the toughening agent and the polylactic acid resin matrix becomes low, which results in a decrease in the strength of the polylactic acid plastic, and if the particle size exceeds the lower limit of the above particle size range, the toughening effect becomes insignificant, and the segregation of the polyamide thermoplastic elastomer in the polylactic acid resin tends to occur.
Experimental example 4
The tensile test was carried out on the sample obtained in example 1, and the results are shown in FIG. 8:
FIG. 8 shows the engineering stress-strain curves for example 1 and pure PLLA with tensile strain on the abscissa and tensile stress on the ordinate, and the numbers beside the two curves representing the integrated areas of the two curves for comparative analysis "tensile toughness".
As shown in FIG. 8, it can be seen that the effect of the polylactic acid added with PA1012-PTMO copolymer in example 1 is significantly higher than that of pure PLLA.
Experimental example 5
This experimental example tests the tensile and impact properties of the toughened polylactic acid plastic obtained in examples 1 to 5 and comparative example 1, and compares the above properties with those of the conventional polylactic acid plastic, and the measured data are shown in table 2.
TABLE 2 results of Performance test of examples 1-5 and comparative example 1
The experimental results show that the pure polylactic acid (PLLA) has no obvious crystallization temperature in the process of cooling, while the polylactic acid added with the PA1012-PTMO copolymer in the examples 1-5 has a crystallization peak in the range of 100 ℃ and 120 ℃ and has certain improvement on the tensile and impact resistance properties, which indicates that the addition of the polyamide thermoplastic elastomer containing the PA1012 hard segment can toughen the polylactic acid and improve the crystallinity of the polylactic acid; while comparative example 1 usedAlthough the strength and toughness of the polylactic acid are improved, the elastomer does not have a remarkable crystallization temperature, and the crystallization performance of the polylactic acid cannot be improved.
The above embodiments are only preferred embodiments of the present invention, and not intended to limit the present invention in any way, and although the present invention has been disclosed by the preferred embodiments, it is not intended to limit the present invention, and those skilled in the art can make various changes and modifications to the equivalent embodiments by using the technical contents disclosed above without departing from the technical scope of the present invention, and the embodiments in the above embodiments can be further combined or replaced, but any simple modification, equivalent change and modification made to the above embodiments according to the technical spirit of the present invention still fall within the technical scope of the present invention.
