1. The migration-resistant micro-crosslinked structure environment-friendly plasticizer is characterized by mainly comprising the following raw materials in parts by mass:

10-70 parts of long straight chain epoxidized fatty acid ester;

5-40 parts of a polyester plasticizer;

3-5 parts of ternary chlorine vinegar;

1-3 parts of cellulose acetate butyrate;

3-5 parts of chlorinated paraffin;

0.1-2 parts of antioxidant;

2-12 parts of polyether polyol;

3-20 parts of a polyurethane curing agent;

5-60 parts of chlorinated fatty acid methyl ester

The long straight chain epoxidized fatty acid ester is one or more of epoxidized soybean oil, epoxidized fatty acid methyl ester, epoxidized linseed oil and epoxidized butyl oleate.

2. The migration-resistant micro-crosslinked environment-friendly plasticizer according to claim 1, wherein the polyester plasticizer is any one or more of polypropylene sebacate polyester, adipic acid polyester, polybutylene adipate and dipentaerythritol adipate.

3. The migration-resistant micro-crosslinked environment-friendly plasticizer according to claim 1, wherein the ternary chloride vinegar is one of hydroxyl-type modified ternary chloride vinegar and carboxyl-type modified ternary chloride vinegar.

4. The migration-resistant environmentally friendly plasticizer with a micro-crosslinked structure as claimed in claim 3, wherein the polymerization degree of the hydroxyl modified ternary vinyl chloride vinegar is 500-1000, the mass content of vinyl acetate is 15-20%, and the hydroxyl value is 120-150 mgKOH/g.

5. The migration-resistant environmentally friendly plasticizer with a micro-crosslinked structure as claimed in claim 3, wherein the degree of polymerization of the carboxyl modified ternary chloride vinegar is 500-1000, the content of acetic acid is 20-25, and the K value is 45-60.

6. The migration resistant micro-crosslinked environment-friendly plasticizer according to claim 1, wherein the polyurethane curing agent is any one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, TDI trimer and IPDI trimer; the antioxidant is one or more of bisphenol A, phosphite ester, antioxidant 168 and antioxidant 1010; the chlorinated paraffin is one or more of chlorinated paraffin-52, chlorinated paraffin-70 and chlorohydrocarbon 50.

7. The migration-resistant environmentally friendly plasticizer having a micro-crosslinked structure as defined in claim 1, wherein the polyether polyol has a molecular weight of 2000-4000.

8. The migration-resistant environmentally friendly plasticizer with a micro-crosslinked structure according to claim 7, wherein the polyether polyol is one or more of polyethylene glycol, polypropylene glycol, polyoxypropylene triol ether, polyoxypropylene diamine, polytetrahydrofuran diol and trimethylolpropane polyether.

9. The method for preparing the migration-resistant micro-crosslinked structure environment-friendly plasticizer according to any one of claims 1 to 8, characterized by comprising the steps of:

1) mixing long straight chain epoxidized fatty acid ester and polyester plasticizer, stirring uniformly, heating to 80-100 ℃, adding ternary chlorine vinegar, cellulose acetate butyrate, chlorinated paraffin, antioxidant, keeping the temperature for 1-1.5 h, cooling to 60-70 ℃, adding polyether polyol and polyurethane curing agent, and continuously stirring uniformly;

2) adding chlorinated fatty acid methyl ester into the reaction kettle reacted in the step 1), controlling the temperature to be 70-90 ℃, preserving the heat for 1-1.5 h, and carrying out reduced pressure distillation to obtain the migration-resistant micro-crosslinking structure environment-friendly plasticizer.

10. The preparation method of the migration-resistant environment-friendly plasticizer with a micro-crosslinked structure according to claim 9, wherein the mixing and stirring speed for uniformly mixing the long linear chain epoxidized fatty acid ester and the polyester plasticizer is 120r/min to 200r/min, and the time for continuously stirring uniformly is 0.5h to 1 h.

Background

The main component of the polyvinyl chloride film is polyvinyl chloride, and the polyvinyl chloride film is a film which is used more in the field of packaging and other fields, and other components are required to be added into the PVC film to enhance the performance of the PVC film, such as mechanical property, heat resistance, toughness, ductility and the like. Plasticizers are additives for polymer materials, which are widely used in industrial production, and are also called plasticizers. The plasticizer can improve the performance of the high polymer material, reduce the production cost and improve the production benefit, and is an important chemical product additive, and the content of the plasticizer can reach 50 percent of the product sometimes. Plasticizer molecules can be inserted between polymer molecular chains to weaken intermolecular force, increase the distance and the activity space between the polymer molecular chains, increase the plasticity of the polymer and reduce the processing temperature of the polymer, so that the flexibility of the plastic is enhanced by adding the plasticizer in the plastic processing, the plastic is easy to process, and the plasticizer is widely applied to polymer material additives.

The plasticizer which is most commonly used in the current PVC material is phthalate, which accounts for more than 70 percent of the total amount of the plasticizer, and the plasticizer is not chemically bonded with polyolefin plastic molecules but is connected with the polyolefin plastic molecules by hydrogen bonds or van der Waals forces, so that the bonding force is weak and the plasticizer can diffuse from the interior of the plastic into the external environment. With the development of the plastic industry, phthalate esters are ubiquitous in atmospheric fly ash, industrial waste water, rivers, soil and solid waste, have been detected in food, drinking water and human body fluids, and have become one of the most prevalent pollutants worldwide. These compounds all have estrogen-like action, influence the normal secretion of hormone in the organism, can produce teratogenic, carcinogenic and mutagenic effects, because of their potential carcinogenicity in recent years, threaten human health seriously, receive all parties' extensive attention, the research to the substitute of phthalate is also urgent.

The Chinese patent application with the publication number of CN 109867930A discloses a migration-resistant environment-friendly plasticizer, a plasticizer additive, a migration-resistant additive and a dispersing additive are respectively prepared, and the prepared plasticizer additive resin can have good compatibility with a plasticizer matrix. The technology utilizes hydrogen bonds in the migration-resistant additive polyurethane oligomer to fix the plasticizer and the resin matrix, and improves the migration resistance of the plasticizer. However, the manufacturing process of the plasticizer is complex, and the migration-resistant polyurethane additive exists in the plasticizer system in a dispersed phase mode only by a physical blending method, so that under the condition of low dosage, the migration-resistant polyurethane additive has a limited effect of limiting the escape of the small-molecular plasticizer and can only play a role of fixing locally, and meanwhile, the technology adds diethyl ether in the preparation process, so that the flash point is very low, and the difficulty in the preparation and transportation processes is increased. Therefore, the plasticizer with rich raw material sources and excellent migration resistance is prepared, and has great significance for production and transportation of PVC.

The Chinese invention patent application with the publication number of CN110041489A discloses a migration-resistant plasticizer for a polyurethane sealant and a polyurethane building sealant, wherein the migration-resistant plasticizer is prepared from the following components in percentage by mass: 70-92% of polypropylene oxide polyol, 5-18% of polyisocyanate and 1-15% of a blocking agent; the viscosity of the migration-resistant plasticizer at 25 ℃ is 10000-35000 mpa & s. In the technology, a heating mode is adopted to remove the micromolecule plasticizer, but the set temperature cannot reach the boiling point of part of the alcohol end-capping agent, so that the plasticizer contains micromolecule alcohols, the micromolecule alcohols can be separated out in the sealant, the migration resistance of the plasticizer is influenced, and the service life of the polyurethane sealant is shortened. In the technology, the plasticizer is essentially terminated by hydroxyl on the basis of the polyurethane prepolymer, the structure is a straight chain structure, and the straight chain is easy to break under the high-temperature condition, so that the migration volume is increased, and the temperature resistance is poor.

Disclosure of Invention

Aiming at the problems that the plasticizers such as DOP, DOTP and the like adopted in the prior art have carcinogenicity in the aspect of human health, and the biodiesel plasticizer does not have the health problem and has poor temperature resistance, the invention provides the environment-friendly plasticizer which has the advantages of environmental protection, good migration resistance at the temperature of over 75 ℃, mechanical property and low cost and has a migration-resistant micro-crosslinking structure, and the preparation method thereof.

In the Chinese patent application CN110041489A, the plasticizer is a hydroxyl-terminated polymer of macromolecule generated by the reaction of polypropylene oxide polyol and isocyanate, and the mobility is reduced by increasing the molecular weight through the reaction of the polypropylene oxide polyol and the isocyanate. Compared with the method for increasing the molecular weight, the method solves the migration problem from the molecular structure, fully utilizes the compatibility of the epoxidized fatty acid ester and the PVC resin by constructing the micro-crosslinking structure, forms an interpenetrating network structure after the reaction of active hydrogen contained in the epoxidized fatty acid ester and isocyanate, and plays an anchor role in a plasticizer polymer by the polyester plasticizer, and the result shows that the micro-crosslinking structure has more obvious effect on preventing the plasticizer from being separated out and has stronger heat-resistant stability. The invention structurally improves the migration resistance of the plasticizer in the material, can well exert the plasticizing effect and the mechanical property of the material, and can reduce the migration rate.

The purpose of the invention is realized by the following technical scheme:

a migration-resistant micro-crosslinked structure environment-friendly plasticizer mainly comprises the following raw materials in parts by mass:

10-70 parts of long straight chain epoxidized fatty acid ester;

5-40 parts of a polyester plasticizer;

3-5 parts of ternary chlorine vinegar;

1-3 parts of cellulose acetate butyrate;

3-5 parts of chlorinated paraffin;

0.1-2 parts of antioxidant;

2-12 parts of polyether polyol;

3-20 parts of a polyurethane curing agent;

5-60 parts of chlorinated fatty acid methyl ester

The long straight chain epoxidized fatty acid ester is one or more of epoxidized soybean oil, epoxidized fatty acid methyl ester, epoxidized linseed oil and epoxidized butyl oleate.

To further achieve the object of the present invention, preferably, the polyester plasticizer is any one or more of polypropylene sebacate polyester, adipic acid polyester, polybutylene adipate and dipentaerythritol adipate.

Preferably, the ternary chlorine vinegar is one of hydroxyl modified ternary chlorine vinegar and carboxyl modified ternary chlorine vinegar.

Preferably, the hydroxyl modified ternary chlorine vinegar has the polymerization degree of 500-1000, the vinyl acetate mass content of 15-20 percent and the hydroxyl value of 120-150 mgKOH/g.

Preferably, the polymerization degree of the carboxyl modified ternary chloride vinegar is 500-1000, the acetic acid content is 20-25, and the K value is 45-60.

Preferably, the polyurethane curing agent is any one or more of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, TDI trimer and IPDI trimer; the antioxidant is one or more of bisphenol A, phosphite ester, antioxidant 168 and antioxidant 1010; the chlorinated paraffin is one or more of chlorinated paraffin-52, chlorinated paraffin-70 and chlorohydrocarbon 50.

Preferably, the polyether polyol has a molecular weight of 2000-4000.

Preferably, the polyether polyol is one or more of polyethylene glycol, polypropylene glycol, polyoxypropylene triol ether, polyoxypropylene diamine, polytetrahydrofuran diol and trimethylolpropane polyether.

The preparation method of the migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following steps:

1) mixing long straight chain epoxidized fatty acid ester and polyester plasticizer, stirring uniformly, heating to 80-100 ℃, adding ternary chlorine vinegar, cellulose acetate butyrate, chlorinated paraffin, antioxidant, keeping the temperature for 1-1.5 h, cooling to 60-70 ℃, adding polyether polyol and polyurethane curing agent, and continuously stirring uniformly;

2) adding chlorinated fatty acid methyl ester into the reaction kettle reacted in the step 1), controlling the temperature to be 70-90 ℃, preserving the heat for 1-1.5 h, and carrying out reduced pressure distillation to obtain the migration-resistant micro-crosslinking structure environment-friendly plasticizer.

Preferably, the stirring speed for uniformly mixing and stirring the long linear chain epoxidized fatty acid ester and the polyester plasticizer is 120r/min-200r/min, and the time for continuously stirring uniformly is 0.5h-1 h.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) the advantage of good compatibility of epoxy fatty acid ester and chloro fatty acid methyl ester with PVC is utilized to construct a micro-crosslinking structure in the interior to reduce the migration of the epoxy fatty acid ester and chloro fatty acid methyl ester to the surface. The long chain epoxidized fatty acid ester has epoxy group in the long carbon chain, and hydroxyl group in cellulose acetate butyrate and polyether polyol react with polyurethane curing agent to form micro cross-linked network structure, so that the long chain epoxidized fatty acid ester is tied up by the micro cross-linked network to make the plasticizer obtain a structure similar to multi-branched chain.

(2) The polyurethane curing agent reacts with active hydrogen in the epoxidized fatty acid ester, the generated carbamate group has large cohesive energy and high rigidity, and is not easy to move in PVC resin, and the long linear chain epoxidized fatty acid ester has longer chain length and does not have more branched structures, can be freely stretched, reduces the van der Waals force among PVC polymers, and plays a role as a lubricant. Therefore, the micro-crosslinked network is soft and hard interwoven, the long fatty acid chain is used as a soft segment to ensure the flexibility of the product, the polyurethane curing agent provides a tissue skeleton due to larger internal energy, the micro-crosslinked structure has better tension on the micromolecule plasticizer, and the seepage of the micromolecule plasticizer to the outer surface layer of the product can be effectively reduced, so that the PVC has good migration resistance.

(3) The polyurethane curing agent reacts with active hydrogen in the epoxidized fatty acid ester, the generated carbamate group has large cohesive energy and high rigidity, and is not easy to move in PVC resin, and the long linear chain epoxidized fatty acid ester has longer chain length and does not have more branched structures, can be freely stretched, reduces the van der Waals force among PVC polymers, and plays a role as a lubricant. Therefore, the micro-crosslinked network is soft and hard interwoven, the long fatty acid chain is used as a soft segment to ensure the flexibility of the product, the polyurethane curing agent provides a tissue skeleton due to larger internal energy, the micro-crosslinked structure has better tension on the micromolecule plasticizer, and the seepage of the micromolecule plasticizer to the outer surface layer of the product can be effectively reduced, so that the PVC has good migration resistance.

Drawings

FIG. 1 is an infrared spectrum of chlorinated fatty acid methyl ester and migration-resistant micro-crosslinked structure eco-friendly plasticizer in example 1.

FIG. 2 is a schematic representation of a PVC film produced in example 1.

Fig. 3 is an appearance diagram of a PVC film prepared using the plasticizer of example 1 after adsorption with activated carbon at high temperature.

FIG. 4 is an appearance diagram of the PVC film after high-temperature adsorption with activated carbon in example 1, which was subjected to wiping treatment after the surface was washed with ethanol.

FIG. 5 is a structural unit diagram of a plasticizer having a micro-crosslinked structure

Detailed Description

The present invention is further illustrated by the following examples, which are provided only to aid understanding of the present invention and do not limit the scope of the present invention.

Example 1

The migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following raw material formula components in parts by mass:

a preparation method of a migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following steps:

1) taking 30 parts of epoxidized soybean oil, 20 parts of poly (propylene sebacate) and adipic acid polyester 1: 1, stirring 6 parts of dipropylene glycol methyl ether acetate at the speed of 120r/min, heating to 90 ℃, adding 8 parts of a mixture of ternary chloroacetic acid, cellulose acetate butyrate, chlorinated paraffin-70 and an antioxidant 168, keeping the temperature for 1 hour, cooling to 70 ℃, adding 2 parts of PEG-2000, 4 parts of isophorone diisocyanate, and stirring for 0.5 hour;

2) adding 30 parts of chlorinated fatty acid methyl ester into the reaction kettle reacted in the step 1), heating to 80 ℃, preserving heat for 1 hour, and carrying out reduced pressure distillation to finally obtain the migration-resistant micro-crosslinking structure environment-friendly plasticizer.

Taking the migration-resistant micro-crosslinked structure environment-friendly plasticizer prepared in example 1 as an example, the infrared absorption spectrum of the obtained micro-crosslinked structure environment-friendly plasticizer is measured by a potassium bromide tabletting method and a Bruker VeCtor infrared spectrometer. In the figure 1, a and b are respectively chlorinated fatty acid methyl ester and a migration-resistant micro-crosslinking structure environment-friendly plasticizer. Chlorinated fatty acid methyl ester at 730cm^-1Has absorption peak, which is long-chain alkyl CH in methyl ester of chloro fatty acid₂The in-plane rocking vibration absorption peak of (1). The migration-resistant micro-crosslinked structure environment-friendly plasticizer is 3471cm^-1And 1733cm^-1Has an absorption peak at 3471cm^-1The peak at (A) corresponds to the absorption peak of N-H stretching vibration in carbamate, 1733cm^-1The peak corresponds to a stretching vibration absorption peak of C ═ O in the amine ester group, which shows that-NCO and-OH in the system react to generate the amine ester group and form a crosslinking structure. FIG. 5 is a diagram of structural units of a micro-crosslinked network of migration resistant plasticizer, long linear chain fatty acid ester serving as a soft segment part in the micro-crosslinked network due to its long chain length and strong mobility between PVC resin molecules, and polyurethane curing agent serving as a hard segment part providing a tissue skeleton for the micro-crosslinked network in the plasticizer due to its large cohesive energy. The soft segment part of the structure can ensure the flexibility of the plasticizer product, and the hard segment mainly supports the skeleton of the micro-crosslinked network to prevent the whole network structure from gathering or migrating.

3) Mixing PVC, a calcium-zinc stabilizer, stearic acid and the migration-resistant micro-crosslinked structure environment-friendly plasticizer prepared in the step 2) according to the formula in the following table 1, stirring for 2min in a high-speed dispersion machine, mixing in an internal mixer at 150 ℃, and extruding to form the PVC film.

TABLE 1

Cutting the film obtained in step 3) into 2cm by 2cm squares, and spreading the squares in a beaker for 20cm³Placing dried activated carbon powder into a cut PVC film test piece, and spreading on the film for 20cm³The activated carbon powder of (3), and embedding the membrane. Placing the test piece into a drying oven at 100 ℃, standing for 6 hours, taking out the test piece, cleaning the surface with ethanol, wiping the surface with filter paper, weighing the lost mass of the test piece, expressing the migration resistance by using the mass loss rate, and summarizing the test results in table 2.

FIG. 1 is a view showing the outer appearance of a PVC film prepared in step 3) of example 1, which has high transparency and a very smooth surface, and the surface does not emit oil when left for a long time; FIG. 2 is a graph showing the appearance of a PVC film prepared by using the plasticizer obtained in the present example after adsorption on activated carbon at high temperature; FIG. 3 is an appearance diagram of a PVC film after activated carbon high-temperature adsorption, which is subjected to surface cleaning and drying treatment, and still has good transparency and does not show sticky or dry conditions, namely, the micro-crosslinked structure of the PVC film is not destroyed at high temperature, so that a small-molecule plasticizer is separated out and sticky or the small-molecule plasticizer is separated out, so that the film is dried.

Example 2

The migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following raw material formula components in parts by mass:

a preparation method of a migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following steps:

(1) taking 25 parts of epoxy fatty acid methyl ester, 16 parts of polytrimethylene sebacate and 6 parts of dipropylene glycol methyl ether acetate, stirring at the speed of 120r/min, heating to 90 ℃, adding a mixture of 8 parts of ternary chlorine vinegar, cellulose acetate butyrate, chlorinated paraffin-70 and an antioxidant 168, cooling to 65 ℃ after heat preservation for 1h, adding 4 parts of polyethylene glycol and 6 parts of toluene diisocyanate, and stirring for 0.5 h;

(2) adding 35 parts of chlorinated fatty acid methyl ester into the reaction kettle reacted in the step (1), heating to 70 ℃, preserving heat for 1 hour, and carrying out reduced pressure distillation to obtain the final migration-resistant environment-friendly plasticizer;

(3) the same as in example 1.

Example 3

The migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following raw material formula components in parts by mass:

the preparation method of the embodiment comprises the following steps:

(1) taking 50 parts of epoxy fatty acid methyl ester, 10 parts of adipic acid polyester and 6 parts of dipropylene glycol methyl ether acetate, stirring at the speed of 120r/min, heating to 100 ℃, adding a mixture of 10 parts of ternary chloride vinegar, cellulose acetate butyrate, chlorinated paraffin-70 and an antioxidant 168, cooling to 70 ℃ after keeping the temperature for 1h, adding 3 parts of polytetrahydrofuran glycol and 6 parts of toluene diisocyanate, and stirring for 0.5 h;

(2) adding chlorinated fatty acid methyl ester into the reaction kettle reacted in the step (1), heating to 80 ℃, preserving heat for 1h, and carrying out reduced pressure distillation to obtain the final migration-resistant environment-friendly plasticizer;

(3) the same as in example 1.

Example 4

The migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following raw material formula components in parts by mass:

a preparation method of a migration-resistant micro-crosslinked structure environment-friendly plasticizer comprises the following steps:

(1) taking 40 parts of epoxidized soybean oil, 15 parts of adipic acid polyester and 7 parts of dipropylene glycol methyl ether acetate, stirring at the speed of 120r/min, heating to 90 ℃, adding a mixture of 12 parts of ternary chlorine vinegar, cellulose acetate butyrate, chlorinated paraffin-70 and an antioxidant 168, keeping the temperature for 1 hour, cooling to 60 ℃, adding 3 parts of polypropylene glycol and 8 parts of toluene diisocyanate, and stirring for 0.5 hour;

(2) adding 15 parts of chlorinated fatty acid methyl ester into the reaction kettle reacted in the step (1), heating to 90 ℃, preserving heat for 1h, and carrying out reduced pressure distillation to obtain the final migration-resistant environment-friendly plasticizer;

(3) the same as in example 1.

Comparative example 1

This comparative example provides a migration resistant micro-crosslinked structure eco-friendly plasticizer having the same formulation and method as example 1 except that fully hydrogenated chlorinated fatty acid methyl ester was used instead of epoxidized soybean oil in example 1.

Comparative example 2

The migration-resistant micro-crosslinked structure environment-friendly plasticizer provided by the comparative example uses butyl acrylate to replace the epoxidized soybean oil in example 1, and other formulas and methods are the same as those in example 1.

The performance of the migration-resistant micro-crosslinked structure environment-friendly plasticizer prepared in each of the above examples and comparative examples was tested according to the following test method, and the test results are shown in table 2 below.

(1) And (3) testing the migration resistant temperature: and (3) putting the PVC film prepared in the step (3) into an oven, setting different temperatures, and taking the highest temperature as the migration-resistant temperature on the premise of placing for at least one week and not bleeding the surface of the film.

(2) Elongation at break test: the prepared migration-resistant micro-crosslinked structure environment-friendly plasticizer is used for preparing a PVC film in the step 3, and the elongation at break is tested according to GB/T1040.3-2006 Plastic tensile Property test for testing the tensile property of PVC products.

(3) Migration resistance test: the migration resistance of the plasticizer was tested by reference to ISO 176-2005 activated carbon adsorption method.

TABLE 2

As can be seen from the performance test data in Table 2, the migration-resistant micro-crosslinked structure environment-friendly plasticizer in examples 1 to 4 has good performance. The examples and the comparative examples do not contain phthalate, and meet the current limit regulation of phthalate in China. The examples did not migrate below 75 deg.C, while the comparative examples were used at lower temperature ranges than the examples. In the migration resistance test, the comparative examples exceed 5 percent, the surface oil bleeding phenomenon is obvious, and in the comparative example 1, the completely hydrogenated chlorinated fatty acid methyl ester is used, unsaturated double bonds and epoxy bonds are not available, active hydrogen cannot be provided, so that the free isocyanate is too high, the micro cross-linked network is small, and the migration resistance is poor; in comparative example 2, although butyl acrylate can provide double bonds, the chain length is short, the reactivity is high, the migration resistance temperature of the prepared PVC membrane is low, and the micro-crosslinked network is easy to dissociate, so that the migration resistance performance is poor.

In CN110041489A, a plasticizer is a hydroxyl-terminated polymer of macromolecules generated by the reaction of polypropylene oxide polyol and isocyanate, the structure of the plasticizer is a straight-chain structure, the migration amount of the plasticizer is very large after the straight chain of the plasticizer is broken under a high-temperature condition, and the plasticizer is suitable for 70 ℃ and the mobility of the plasticizer is increased along with the temperature rise. The plasticizer with the micro-crosslinking structure is prepared by using epoxidized fatty acid ester, the micro-crosslinking network contains epoxy bonds, the thermal stability of the plasticizer is strong, the mobility at 70 ℃ is 0, the migration resistant temperature of all the embodiments is higher than 70 ℃, and the migration resistant effect at the same temperature is obviously better than that of CN 110041489A.

Aiming at the problems that the plasticizer such as DOP, DOTP and the like adopted at present has carcinogenicity in the aspect of human health, and the plasticizer such as biodiesel does not have a health problem, the problem of migration of the plasticizer is solved from the aspect of molecular structure, by constructing a micro-crosslinking structure, the compatibility of epoxidized fatty acid ester and PVC resin is fully utilized, and an interpenetrating network structure can be formed after active hydrogen contained in the epoxidized fatty acid ester reacts with isocyanate, so that the micro-crosslinking structure has a more obvious effect on preventing the plasticizer from being separated out, and the heat-resistant stability is stronger. The micro-crosslinked environment-friendly plasticizer can be applied to plastic products, plastic films, food packages, children toys and the like. Plasticizers are used in plastic products to increase the flexibility, ductility and plasticity of the plastic and to reduce the flow temperature and hardness of the plastic, and the common plasticizers are phthalates such as DOP, DEP and DINP, which have the obvious disadvantage of carcinogenicity. The plasticizer disclosed by the invention does not contain a benzene ring structure, is very good in compatibility with PVC, and improves the flexibility and ductility of plastic products. After the plasticizer and the PVC resin are blended and banburied at high temperature, PVC products with different excellent performances can be prepared according to requirements.

The described embodiments are only some, not all embodiments of the invention. Other embodiments, which can be derived by one of ordinary skill in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.