A PET composite material and preparation method thereof

Abstract

The invention relates to a PET composite material, belonging to the technical field of composite materials, comprising the following raw materials: PET resin, composite functional agent, glass fiber, plasticizer, crosslinking agent and coupling agent; the invention also discloses a preparation method of the PET composite material, comprising: screening, weighing, cleaning glass fiber and heat treatment, stretching, drying, mixing and extruding; the self-made composite functional agent is added to the PET composite material, the composite functional agent has the characteristics of a quaternary ammonium salt structure macromolecular polymer, can exert excellent antistatic performance, contains a benzene ring and an organic heterocyclic structure, can improve the thermal performance of the PET composite material, and also has the characteristics of a phosphite compound, can give the PET composite material flame retardancy, the finally obtained PET composite material has a heat deformation temperature of up to 194°C, is not easy to burn, has good corona resistance, and can be widely used in the fields of electrical housings, wind turbine blades, decorative materials, etc.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a PET composite material and a preparation method thereof. Background Art

[0002] PET is the most important variety of thermoplastic polyester, also known as polyester resin. It is made by exchanging dimethyl terephthalate with ethylene glycol or esterifying terephthalic acid with ethylene glycol to synthesize dihydroxyethyl terephthalate, and then polycondensing it. Its appearance is usually milky white or light yellow, and its surface is smooth. It is a plastic with excellent comprehensive performance. It can maintain good mechanical properties in a large temperature range, and its creep resistance, fatigue resistance, friction resistance, and dimensional stability are all very good. The long-term use temperature can reach 120℃. In addition, it also has good insulation properties, and its electrical properties are still not affected at higher temperatures; but PET also has the disadvantage of poor corona resistance. For example, long-term contact with static electricity will cause its quality to decline and affect its service life. In addition, it itself is not flame retardant and has poor safety performance. The above are all problems that PET resin needs to solve urgently. Summary of the invention

[0003] The object of the present invention is to provide a PET composite material and a preparation method thereof, so as to solve the problems in the above-mentioned background technology.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] A PET composite material, comprising the following raw materials in parts by weight: 60-65 parts of PET resin, 10-15 parts of composite functional agent, 11-25 parts of glass fiber, 3-5 parts of plasticizer, 1-3 parts of cross-linking agent, and 0.5-1 parts of coupling agent;

[0006] The preparation method of the composite material comprises the following steps:

[0007] Step 1: Screen the PET resin and weigh each raw material according to a predetermined mass percentage;

[0008] Step 2: Clean the glass fiber, heat treat it at 240-280°C for 35-45min, stretch it, and dry it;

[0009] Step 3: All raw materials are mixed and added into a twin-screw extruder for extrusion to obtain a PET composite material. The temperature of zone 1 is set to 235-245°C, the temperature of zone 2 is set to 255-265°C, the temperature of zone 3 is set to 260-270°C, the temperature of zone 4 is set to 275-285°C, and the screw speed is set to 210-240r / min;

[0010] Furthermore, the plasticizer is one of dioctyl terephthalate and diisooctyl phthalate;

[0011] Further, the cross-linking agent is one of divinylbenzene, diisocyanate, and N,N'-methylenebisacrylamide;

[0012] Further, the coupling agent is PET-g-MAH;

[0013] Furthermore, the composite functional agent is prepared by the following steps:

[0014] Step 1, add dimethyl phosphite, sulfonyl chloride and carbon tetrachloride into a three-necked flask, install a condenser and a thermometer, turn on the magnetic stirrer, react at 45-60°C for 2h, and after the reaction is completed, rotary evaporate to obtain intermediate 1;

[0015] Step 2, add dimethyl sulfoxide and sodium hydroxide solution into a three-necked flask, install a condenser and a thermometer, turn on the magnetic stirring, then add intermediate 1, phthalimide, and cuprous iodide, continue to introduce argon protection, react at 90°C for 18h, after the reaction is completed, perform column chromatography, and then perform rotary evaporation to obtain intermediate 2;

[0016] Step 3, add 4-chlorobutyric acid and intermediate 2 into a three-necked flask, install a condenser and a thermometer, turn on magnetic stirring, react at 70°C for 4 hours, cool after the reaction, add ice water to the three-necked flask, filter, recrystallize the filter cake with acetone, and dry to obtain intermediate 3;

[0017] Step 4, chitosan oligosaccharide, 1-ethyl-(3-dimethylaminopropyl) carbodiimide, N-hydroxysuccinimide, and dilute hydrochloric acid are added to a three-necked flask, a condenser and a thermometer are installed, and magnetic stirring is turned on. After complete dissolution, the N,N-dimethylformamide solution of intermediate 3 is added dropwise using a high-pressure dropping pump. The dropping time is 1 hour. After the dropping is completed, the mixture is reacted at 35° C. for 72 hours. After the reaction is completed, ethanol is added to the three-necked flask, and vacuum filtration is performed. After drying, the composite functional agent is obtained;

[0018] Further: the amount ratio of dimethyl phosphite, sulfonyl chloride and carbon tetrachloride used in step 1 is 11g:13.5g:170-200g;

[0019] Further: the sodium hydroxide solution used in step 2 is a sodium hydroxide aqueous solution with a mass fraction of 17%, and the amount ratio of dimethyl sulfoxide, sodium hydroxide solution, intermediate 1, phthalimide and cuprous iodide used is 220g:110g:11g:13.2-15g:9.5g;

[0020] Further: the ratio of 4-chlorobutyric acid and intermediate 2 used in step 3 is 10-13g:18g;

[0021] Further: the mass fraction of the dilute hydrochloric acid used in step 4 is 15%, and the amount ratio of the chitosan oligosaccharide, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and dilute hydrochloric acid used is 13-15g:8.3g:3.6g:300-350g;

[0022] Furthermore: the N,N-dimethylformamide solution of intermediate 3 used in step 4 is prepared by mixing intermediate 3 and N,N-dimethylformamide in a ratio of 25 g:130-150 g.

[0023] Beneficial effects of the present invention:

[0024] 1) The present invention uses PET resin, composite functional agent, glass fiber, plasticizer, synergist, crosslinking agent and coupling agent as raw materials to prepare a PET composite material, which can effectively improve the poor corona resistance of PET material;

[0025] 2) The present invention uses dimethyl phosphite as a raw material and sulfonyl chloride as a halogenating agent to undergo an electrophilic substitution reaction to obtain an intermediate 1, and then undergoes a CN coupling reaction of a halogen and an imine between the intermediate 1 and phthalimide under the catalysis of cuprous iodide to obtain an intermediate 2, and then the intermediate 2 and 4-chlorobutyric acid undergo a quaternary ammonium salt reaction to obtain an intermediate 3, and finally the intermediate 3 undergoes an N-acylation reaction with the amino group of chitosan oligosaccharide under the activation of 1-ethyl-(3-dimethylaminopropyl)carbodiimide and N-hydroxysuccinimide, and is grafted onto the chitosan oligosaccharide to obtain the final product. Composite functional agent, quaternary ammonium salt macromolecular polymer can be used as a polymer permanent antistatic agent because its molecule contains a large number of hydrophilic groups and can form a "core shell" structure during processing to release the static charge in the system to reduce the generation of static electricity. The present invention modifies it and uses the characteristic that phosphite compounds can form an isolation film to organize combustion when burning to give it flame retardancy, and uses the characteristics of benzene rings and organic heterocyclic compounds with large cohesive energy and high thermal decomposition temperature to increase its system rigidity, so as to enhance its heat resistance and reduce its loss in the preparation process of PET composite materials;

[0026] 3) The PET composite material of the present invention has good fatigue resistance, dimensional stability, and good electrical insulation. Due to the addition of the composite functional agent, it can effectively release the static charge accumulated inside, and the corona resistance is greatly improved. In addition, the PET composite material of the present invention has good heat resistance and flame retardancy, and its safety and stability are greatly improved. It can be widely used in the fields of electrical housings, decorative materials, wind turbine blades, etc. DETAILED DESCRIPTION

[0027] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example 1

[0029] A composite functional agent is prepared by the following steps:

[0030] Step 1, add 11g of dimethyl phosphite, 13.5g of sulfuryl chloride, and 170g of carbon tetrachloride into a container, install a condenser and a thermometer, turn on a magnetic stirrer, and react at 45°C for 2h. After the reaction is completed, rotary evaporation is performed to obtain intermediate 1;

[0031] Step 2, 22g of dimethyl sulfoxide and 110g of 17% sodium hydroxide solution are added to a container, a condenser and a thermometer are installed, magnetic stirring is turned on, and then 11g of intermediate 1, 13.2g of phthalimide, and 9.5g of cuprous iodide are added thereto, argon gas is continuously introduced thereto for protection, and the reaction is carried out at 90°C for 18h. After the reaction is completed, column chromatography is performed, and then rotary evaporation is performed to obtain intermediate 2;

[0032] Step 3, add 10g 4-chlorobutyric acid and 18g intermediate 2 into a container, install a condenser and a thermometer, turn on magnetic stirring, react at 70°C for 4h, cool after the reaction, add ice water to a three-necked flask, filter, recrystallize the filter cake with acetone, and dry to obtain intermediate 3;

[0033] Step 4, add 13g of chitosan oligosaccharide, 8.3g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 3.6g of N-hydroxysuccinimide, and 300g of dilute hydrochloric acid with a mass fraction of 15% into a container, install a condenser and a thermometer, turn on the magnetic stirring, and after complete dissolution, use a high-pressure dropping pump to drop a solution prepared by 25g of intermediate 3 and 130g of N,N-dimethylformamide. The dropping time is 1h. After the dropping is completed, react at 35°C for 72h. After the reaction is completed, add ethanol to the container, vacuum filter, and dry to obtain the composite functional agent.

[0034] Example 2

[0035] A composite functional agent is prepared by the following steps:

[0036] Step 1, add 11g of dimethyl phosphite, 13.5g of sulfuryl chloride, and 185g of carbon tetrachloride into a container, install a condenser and a thermometer, turn on a magnetic stirrer, and react at 52°C for 2h. After the reaction is completed, rotary evaporation is performed to obtain intermediate 1;

[0037] Step 2, 22g of dimethyl sulfoxide and 110g of 17% sodium hydroxide solution are added to a container, a condenser and a thermometer are installed, magnetic stirring is turned on, and then 11g of intermediate 1, 14.1g of phthalimide, and 9.5g of cuprous iodide are added thereto, argon gas is continuously introduced thereto for protection, and the reaction is carried out at 90°C for 18h. After the reaction is completed, column chromatography is performed, and then rotary evaporation is performed to obtain intermediate 2;

[0038] Step 3, add 11.5g 4-chlorobutyric acid and 18g intermediate 2 into a container, install a condenser and a thermometer, turn on magnetic stirring, react at 70°C for 4h, cool after the reaction, add ice water to a three-necked flask, filter, recrystallize the filter cake with acetone, and dry to obtain intermediate 3;

[0039] Step 4, add 14g of chitosan oligosaccharide, 8.3g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 3.6g of N-hydroxysuccinimide, and 325g of dilute hydrochloric acid with a mass fraction of 15% into a container, install a condenser and a thermometer, turn on the magnetic stirring, and after complete dissolution, use a high-pressure dropping pump to drop a solution prepared by 25g of intermediate 3 and 140g of N,N-dimethylformamide. The dropping time is 1h. After the dropping is completed, react at 35°C for 72h. After the reaction is completed, add ethanol to the container, vacuum filter, and dry to obtain the composite functional agent.

[0040] Example 3

[0041] A composite functional agent is prepared by the following steps:

[0042] Step 1, add 11g of dimethyl phosphite, 13.5g of sulfuryl chloride, and 200g of carbon tetrachloride into a container, install a condenser and a thermometer, turn on a magnetic stirrer, and react at 60°C for 2h. After the reaction is completed, rotary evaporation is performed to obtain intermediate 1;

[0043] Step 2, 22g of dimethyl sulfoxide and 110g of 17% sodium hydroxide solution are added to a container, a condenser and a thermometer are installed, magnetic stirring is turned on, and then 11g of intermediate 1, 15g of phthalimide, and 9.5g of cuprous iodide are added thereto, argon gas is continuously introduced thereto for protection, and the reaction is carried out at 90°C for 18h. After the reaction is completed, column chromatography is performed, and then rotary evaporation is performed to obtain intermediate 2;

[0044] Step 3, add 13g 4-chlorobutyric acid and 18g intermediate 2 into a container, install a condenser and a thermometer, turn on magnetic stirring, react at 70°C for 4h, cool after the reaction, add ice water to a three-necked flask, filter, recrystallize the filter cake with acetone, and dry to obtain intermediate 3;

[0045] Step 4, add 15g of chitosan oligosaccharide, 8.3g of 1-ethyl-(3-dimethylaminopropyl)carbodiimide, 3.6g of N-hydroxysuccinimide, and 350g of dilute hydrochloric acid with a mass fraction of 15% into a container, install a condenser and a thermometer, turn on the magnetic stirring, and after complete dissolution, use a high-pressure dropping pump to drop a solution prepared by 25g of intermediate 3 and 150g of N,N-dimethylformamide. The dropping time is 1h. After the dropping is completed, react at 35°C for 72h. After the reaction is completed, add ethanol to the container, vacuum filter, and dry to obtain the composite functional agent.

[0046] Comparative Example 1

[0047] This comparative example is an antistatic agent sold by Hangzhou Yongsheng Plastic Antistatic Material Factory.

[0048] 1g of the composite functional agent obtained in Examples 1-3 and the antistatic agent in Comparative Example 1 were respectively mixed with 9g of PET resin to make 10g of PET sheets. The PET sheets without any other substances added were used as blank control groups. The resistance was measured. After 3 months, the resistance was measured again. The final results are shown in Table 1:

[0049] Table 1

[0050]

[0051] It can be seen from Table 1 that the resistance of the PET sheet to which the composite functional agent of Examples 1-3 is added is much lower than that of Comparative Example 1, and its resistance has not changed significantly after three months, indicating that the composite functional agent of the present invention can not only effectively improve the antistatic performance of the material but also has good stability and can be effective for a long time.

[0052] Example 4

[0053] A PET composite material, comprising the following raw materials in parts by weight:

[0054] 60 parts of PET resin, 10 parts of the composite functional agent obtained in Example 1, 21 parts of glass fiber, 5 parts of dioctyl terephthalate, 3 parts of divinylbenzene, and 1 part of PET-g-MAH;

[0055] A method for preparing a PET composite material comprises the following steps:

[0056] Step 1: Screen the PET resin and weigh each raw material according to the predetermined mass fraction;

[0057] Step 2: The glass fiber is cleaned, heat treated at 280°C for 45 min, stretched, and dried;

[0058] Step 3: All raw materials are mixed, added into a twin-screw extruder, and extruded to obtain a PET composite material. The temperature of zone 1, zone 2, zone 3, zone 4, and screw speed are set to 240 r / min.

[0059] Example 5

[0060] A PET composite material, comprising the following raw materials in parts by weight:

[0061] 62.5 parts of PET resin, 12.5 parts of the composite functional agent obtained in Example 2, 16 parts of glass fiber, 5 parts of diisooctyl phthalate, 3 parts of diisocyanate, and 1 part of PET-g-MAH;

[0062] A method for preparing a PET composite material comprises the following steps:

[0063] Step 1: Screen the PET resin and weigh each raw material according to the predetermined mass fraction;

[0064] Step 2: The glass fiber is cleaned, heat treated at 260°C for 40 min, stretched, and dried;

[0065] Step 3: All raw materials are mixed, added into a twin-screw extruder, and extruded to obtain a PET composite material. The temperature of zone 1 is set to 240°C, the temperature of zone 2 is set to 260°C, the temperature of zone 3 is set to 265°C, the temperature of zone 4 is set to 280°C, and the screw speed is set to 220r / min.

[0066] Example 6

[0067] A PET composite material, comprising the following raw materials in parts by weight:

[0068] 64.5 parts of PET resin, 15 parts of the composite functional agent obtained in Example 3, 16 parts of glass fiber, 3 parts of dioctyl terephthalate, 1 part of N,N'-methylenebisacrylamide, and 0.5 parts of PET-g-MAH;

[0069] A method for preparing a PET composite material comprises the following steps:

[0070] Step 1: Screen the PET resin and weigh each raw material according to the predetermined mass fraction;

[0071] Step 2: The glass fiber is cleaned, heat treated at 240°C for 35 min, stretched, and dried;

[0072] Step 3: All raw materials are mixed, added into a twin-screw extruder, and extruded to obtain a PET composite material. The temperature of zone 1, zone 2, zone 3, zone 4, and screw speed are set to 210 r / min.

[0073] Comparative Example 2

[0074] The composite functional agent in Example 6 was removed, and the other raw materials and preparation process remained unchanged.

[0075] Comparative Example 3

[0076] This comparative example is the antistatic PET sheet sold by Suzhou Aokai Plastic Materials Co., Ltd.

[0077] The PET composite materials of Examples 4-6 and Comparative Examples 2-3 were subjected to combustion tests and thermal performance tests:

[0078] Table 2

[0079]

[0080]

[0081] It can be seen from Table 2 that the thermal deformation temperatures of the PET composite materials of Examples 4-6 are higher than those of Comparative Examples 2-3, and they are difficult to burn, and their safety is greatly improved, indicating that the addition of the composite functional agent effectively improves the thermal properties of the PET composite material and imparts it with flame retardancy, thereby broadening the application scenarios of the PET composite material, and can be widely used in the fields of electrical housings, decorative materials, wind turbine blades, etc.

[0082] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A PET composite material, characterized in that: The raw materials include the following parts by weight: 60-65 parts of PET resin, 10-15 parts of composite functional agent, 11-25 parts of glass fiber, 3-5 parts of plasticizer, 1-3 parts of cross-linking agent, and 0.5-1 parts of coupling agent; Wherein, the composite functional agent is prepared by the following steps: Step 1, add dimethyl phosphite, sulfuryl chloride and carbon tetrachloride into a container, and react at 45-60°C for 2h to obtain intermediate 1; Step 2, dimethyl sulfoxide and sodium hydroxide solution are added into a container, and then intermediate 1, phthalimide and cuprous iodide are added thereto, inert gas is continuously introduced thereto for protection, and the mixture is reacted at 90° C. for 18 hours to obtain intermediate 2; Step 3, adding 4-chlorobutyric acid and intermediate 2 into a container, reacting at 70° C. for 4 h to obtain intermediate 3; Step 4, chitosan oligosaccharide, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and dilute hydrochloric acid are added into a container, and after they are completely dissolved, the N,N-dimethylformamide solution of intermediate 3 is added dropwise thereto for 1 hour. After the addition is completed, the reaction is carried out at 35° C. for 72 hours to obtain the composite functional agent.

2. A PET composite material according to claim 1, characterized in that: The plasticizer is one of dioctyl terephthalate and diisooctyl phthalate, the crosslinking agent is one of divinylbenzene, diisocyanate and N,N'-methylenebisacrylamide, and the coupling agent is PET-g-MAH.

3. A PET composite material according to claim 1, characterized in that: The amount ratio of dimethyl phosphite, sulfuryl chloride and carbon tetrachloride used in step 1 is 11g:13.5g:170-200g.

4. A PET composite material according to claim 1, characterized in that: The sodium hydroxide solution used in step 2 is a sodium hydroxide aqueous solution with a mass fraction of 17%, and the amount ratio of dimethyl sulfoxide, sodium hydroxide solution, intermediate 1, phthalimide and cuprous iodide used is 220g:110g:11g:13.2-15g:9.5g.

5. A PET composite material according to claim 1, characterized in that: The amounts of 4-chlorobutyric acid and intermediate 2 used in step 3 are 10-13 g:18 g.

6. A PET composite material according to claim 1, characterized in that: The mass fraction of the dilute hydrochloric acid used in step 4 is 15%, and the amount ratio of the chitosan oligosaccharide, 1-ethyl-(3-dimethylaminopropyl)carbodiimide, N-hydroxysuccinimide, and dilute hydrochloric acid used is 13-15g:8.3g:3.6g:300-350g.

7. A PET composite material according to claim 1, characterized in that: The N,N-dimethylformamide solution of intermediate 3 used in step 4 is prepared by mixing intermediate 3 and N,N-dimethylformamide in a ratio of 25 g:130-150 g.

8. A method for preparing a PET composite material according to any one of claims 1 to 7, characterized in that: The following steps are involved: Step 1: Screen the PET resin and weigh each raw material according to the predetermined mass fraction; Step 2: Cleaning, heat treating, stretching and drying the glass fiber; Step 3: All raw materials are mixed, added into a twin-screw extruder, and extruded to obtain a PET composite material.

9. The method for preparing a PET composite material according to claim 8, characterized in that: The temperature condition of the heat treatment in step 2 is 240-280° C., and the time condition is 35-45 min.

10. The method for preparing a PET composite material according to claim 8, characterized in that: The settings of the twin-screw extruder are: zone 1 235-245°C, zone 2 255-265°C, zone 3 260-270°C, zone 4 275-285°C, and screw speed 210-240r / min.

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