阅读说明：本技术 增韧复合物、pbt复合材料及其制备方法 (Toughened composite, PBT composite material and preparation method thereof ) 是由 陈鹏 廖虎辉 刘亮 方浩 俞建 于 2020-12-28 设计创作，主要内容包括：本发明公开了一种增韧组合物、PBT复合材料及其制备方法,该增韧复合物由第一增韧组分、第二增韧组分和第三增韧组分混合制备而成,所述第一增韧组分为马来酸酐接枝聚合物或共聚物、环氧官能团化的接枝聚合物或共聚物中的至少一种,所述第二增韧组分为乙烯丙烯酸丁酯共聚物,所述第三增韧组分为纯粉型聚四氟乙烯。通过该增韧复合物制得的PBT复合材料具有优异的韧性、拉伸强度和流动性。(The invention discloses a toughening composition, a PBT composite material and a preparation method thereof, wherein the toughening composite material is prepared by mixing a first toughening component, a second toughening component and a third toughening component, the first toughening component is at least one of a maleic anhydride graft polymer or copolymer and an epoxy functionalized graft polymer or copolymer, the second toughening component is an ethylene butyl acrylate copolymer, and the third toughening component is pure powder type polytetrafluoroethylene. The PBT composite material prepared by the toughening compound has excellent toughness, tensile strength and fluidity.)

1. The toughening composite is characterized by being prepared by mixing a first toughening component, a second toughening component and a third toughening component, wherein the first toughening component is at least one of a maleic anhydride grafted polymer or copolymer and an epoxy functionalized grafted polymer or copolymer, the second toughening component is an ethylene butyl acrylate copolymer, and the third toughening component is pure powder polytetrafluoroethylene.

2. The toughened composite according to claim 1 wherein the weight percent of each toughening component in the toughened composite is: the toughening agent comprises 20-40% of a first toughening component, 50-70% of a second toughening component and 5-10% of a third toughening component.

3. The toughened composite as claimed in claim 1 wherein the first toughening component has a weight percent of grafted functional groups in the range of from 5% to 8%;

in the second toughening component, the weight percentage of butyl acrylate is 20-45%;

the molecular weight of the third toughening component is 10000-40000.

4. The toughened composite according to claim 1 wherein the method of preparing the toughened composite comprises the steps of:

uniformly mixing the first toughening component and the second toughening component, and adding the mixture into a torque rheometer to mix for 2-5 min;

and adding the third toughening component into the torque rheometer, continuously mixing for 2-5 min, taking materials, cooling and crushing to obtain the toughening compound.

5. The toughened composite as claimed in claim 4 wherein the torque rheometer parameters are set to: the temperature is 180-200 ℃, and the rotating speed of the rotor is 80-100 rpm.

6. A PBT composite material is characterized by being prepared from 70-85 parts of polybutylene terephthalate, 10-25 parts of the toughening compound as claimed in any one of claims 1-5, 0.1-0.5 part of an antioxidant, 0.1-0.5 part of a polyester nucleating agent, 0.3-1.0 part of a lubricant and 0.1-0.5 part of sodium dihydrogen phosphate in parts by weight.

7. The PBT composite of claim 6, wherein the polybutylene terephthalate has an intrinsic viscosity of 0.8 to 1.2 dl/g.

8. The PBT composite material of claim 6, wherein the antioxidant is selected from a combination of a primary antioxidant and a secondary antioxidant, the primary antioxidant is selected from antioxidant 1076 or antioxidant 1010, and the secondary antioxidant is selected from any one of antioxidant 168, antioxidant 626, and antioxidant 412S;

the lubricant is selected from any one of stearic acids, fatty acids, ethylene bis stearamide and polyethylene wax.

9. The PBT composite of claim 6, wherein the polyester nucleating agent is selected from long chain linear saturated sodium carboxylates having a carbon chain length of C28-C32.

10. The preparation method of the PBT composite material is characterized by comprising the following steps:

fully mixing 70-85 parts of polybutylene terephthalate, 10-25 parts of the toughening compound as claimed in any one of claims 1-5, 0.1-0.5 part of antioxidant, 0.1-0.5 part of polyester nucleating agent, 0.3-1.0 part of lubricant and 0.1-0.5 part of sodium dihydrogen phosphate according to parts by weight to obtain a uniform mixed material;

and adding the mixed material into a double-screw extruder, and carrying out melting, extrusion and granulation to obtain the PBT composite material, wherein the barrel temperature of the double-screw extruder is 230-260 ℃, the screw rotating speed is 300-450 r/min, the melt pressure is 1.5-2.5 MPa, and the vacuum degree is-0.04-0.1 MPa.

Technical Field

The invention belongs to the technical field of engineering plastics, and particularly relates to a toughening compound, a PBT composite material added with the toughening compound and a preparation method of the PBT composite material.

Background

Polybutylene terephthalate (PBT) as a thermoplastic engineering plastic has the advantages of good mechanical property, high crystallization speed, easy molding, chemical solvent resistance and the like. With the development of electronic and electric appliances and automobile industry, PBT has a wide prospect, but pure PBT materials have the problems of notch sensitivity, low notch impact strength and the like, so the toughening research on PBT is always important work for improving the performance of PBT.

The modified PBT product not only needs to have good toughness, but also needs to meet the requirement of high fluidity for a piece with one die and multiple cavities. At present, the graft copolymer is most commonly used for toughening and modifying the PBT material, and with the increase of the addition proportion, the toughness of the PBT material is greatly improved, but the strength of the material is also reduced; generally, the lost tensile strength and bending strength are supplemented by selecting a high-viscosity PBT resin material, but the processing performance is also reduced sharply, the requirements on the toughness and the processability of the material are higher and higher along with the diversification of a product, the toughening effect is not ideal in some common toughening schemes and modification methods at present, and the applicability is insufficient.

At present, some researches are made on toughened PBT materials in the prior art, for example, Chinese patent application with publication number CN109721969A discloses that high-viscosity PBT resin is adopted, sodium dihydrogen phosphate is added to reduce ester exchange reaction in PBT molecular chains, the molecular chains of alloy materials can be coupled again by introducing a compatilizer, higher molecular weight is kept, and the mechanical strength of the materials is ensured, so that a high-toughness PBT material is prepared, but the impact strength of the toughened compound prepared in the technical scheme can not meet the application environment with higher requirements; for another example, chinese patent application publication No. CN1445281A discloses that a high toughness PBT material is prepared by using a self-made mixture containing ester bond high polymer and a mixture composite toughening agent containing a high polymer with styrene group and a high polymer with hydrogenated butadiene group by changing the structural morphology of the blending system, but the high toughness composite material prepared in the technical scheme has insufficient processability.

Disclosure of Invention

In view of the above, the present invention provides a toughening compound, a PBT composite material and a preparation method thereof, the toughening compound is prepared by compounding three components, and the toughening compound is added into a PBT system, so that the compatibility of PBT is improved, the morphological structure of a blending system is changed, the toughness is increased, the reduction of tensile strength is slowed down, and good processability is maintained, so as to solve the above problems.

In order to achieve the purpose, the invention adopts the following technical scheme:

the invention provides a toughening compound which is prepared by mixing a first toughening component, a second toughening component and a third toughening component, wherein the first toughening component is at least one of a maleic anhydride grafted polymer or copolymer and an epoxy functionalized grafted polymer or copolymer, the second toughening component is an ethylene butyl acrylate copolymer, and the third toughening component is pure powder polytetrafluoroethylene.

According to the invention, three toughening components are innovatively compounded, and surprisingly, the three toughening components have a synergistic effect, so that a 'fishing net state' toughening compound can be obtained, the compatibility between the PBT matrix resin and other additives such as rubber can be improved on one hand, and the morphological structure of a blending system can be changed on the other hand, so that the tensile strength of the PBT material can not be excessively lost while the toughness of the PBT material is remarkably improved, and the PBT material has excellent comprehensive performance.

Further, the ratio of the three toughening components in the present invention is not particularly limited, and preferably, in some specific embodiments of the present invention, the weight percentage of each toughening component in the toughening composite is: the toughening agent comprises 20-40% of a first toughening component, 50-70% of a second toughening component and 5-10% of a third toughening component.

Preferably, in the first toughening component, the weight percentage of the grafting functional group is 5-8%;

in the second toughening component, the weight percentage of butyl acrylate is 20-45%;

the molecular weight of the third toughening component is 10000-40000.

It is to be understood that the parameters of the first toughening component, the second toughening component and the third toughening component are not particularly limited, but the above preferences may be optimized for the properties of the toughened composite, and thus, in some embodiments of the invention, the above preferences are made for the toughening components.

Further, the preparation method of the toughening compound specifically comprises the following steps:

uniformly mixing the first toughening component and the second toughening component, and adding the mixture into a torque rheometer to mix for 2-5 min;

and adding the third toughening component into the torque rheometer, continuously mixing for 2-5 min, taking materials, cooling, and crushing to obtain particles with the diameter of less than or equal to 0.6mm, thereby preparing the toughening compound.

Further, preferably, the parameters of the torque rheometer are set as: the temperature is 180-200 ℃, and the rotating speed of the rotor is 80-100 rpm.

The invention also provides a PBT composite material which is prepared from 70-85 parts of polybutylene terephthalate, 10-25 parts of the toughening compound, 0.1-0.5 part of an antioxidant, 0.1-0.5 part of a polyester nucleating agent, 0.3-1.0 part of a lubricant and 0.1-0.5 part of sodium dihydrogen phosphate in parts by weight.

According to the invention, the toughening compound is added into a PBT formula system, so that the impact toughness of the PBT composite material can be obviously improved, and other properties, especially the reduction of tensile strength, can not be caused. Meanwhile, the polyester nucleating agent and the sodium dihydrogen phosphate are added into the formula system, so that the crystallization speed of the PBT composite material during injection molding is accelerated, and the excessive ester exchange of the polyester at high temperature is avoided, so that the material performance is more stable.

Further, the polybutylene terephthalate used as the matrix resin in the present invention is not particularly limited, and may be any polybutylene terephthalate that is conventional in the art, and in some specific embodiments of the present invention, the polybutylene terephthalate has an intrinsic viscosity of 0.8 to 1.2 dl/g.

Further, the antioxidant and the lubricant in the present invention are not particularly limited, and any antioxidant and lubricant that are conventional in the art can be used in the technical solution of the present invention, preferably, in some specific embodiments of the present invention, the antioxidant is selected from a combination of a primary antioxidant and a secondary antioxidant, the primary antioxidant is selected from antioxidant 1076 or antioxidant 1010, and the secondary antioxidant is selected from any one of antioxidant 168, antioxidant 626 and antioxidant 412S;

the lubricant is selected from any one of stearic acids, fatty acids, ethylene bis stearamide and polyethylene wax.

Further, the polyester nucleating agent is selected from the group consisting of long-chain linear saturated sodium carboxylates having a carbon chain length of C28 to C32, and the polyester nucleating agent of the present invention is preferably used as described above mainly because the polymeric carboxylate can be uniformly dispersed in the polymer by a simple method to obtain a desired effect, has low volatility in processing, and has low migration in the final product, but it is understood that other types of polyester nucleating agents can be used in the present invention in order to increase the crystallization rate in injection molding of the PBT composite material, and is not particularly limited.

The invention also provides a preparation method of the PBT composite material, which comprises the following steps:

fully mixing 70-85 parts of polybutylene terephthalate, 10-25 parts of the toughening compound as described in any one of the preceding claims, 0.1-0.5 part of an antioxidant, 0.1-0.5 part of a polyester nucleating agent, 0.3-1.0 part of a lubricant and 0.1-0.5 part of sodium dihydrogen phosphate according to parts by weight to obtain a uniform mixed material, wherein the step is mainly to fully mix the raw materials for subsequent extrusion processing, so that the mixing mode and parameters (such as rotating speed, time and the like) are not particularly limited as long as the uniform mixing can be realized, and in some specific embodiments of the invention, the raw materials are added into a high-speed mixer to be mixed for 2-4 min;

the mixed material is added into a double-screw extruder, and is subjected to melting, extrusion and granulation to obtain the PBT composite material, wherein the processing parameters of the double-screw extruder are not particularly limited and can be adjusted according to different matrix resins and additives, and in some specific embodiments of the invention, the barrel temperature of the double-screw extruder is 230-260 ℃, the screw rotation speed is 300-450 r/min, the melt pressure is 1.5-2.5 MPa, and the vacuum degree is-0.04-0.1 MPa.

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

in the toughening compound, three toughening components are mutually synergistic to obtain an excellent toughening effect, and when the toughening compound is added into a PBT system, the toughness of the PBT composite material can be obviously improved, the toughness is improved without reducing other properties such as tensile strength, good processing performance is still maintained, and the obtained PBT composite material has an ultra-toughness effect. Can be widely applied to electronic and electric appliances, automobiles and industrial mechanical products.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the specific embodiments illustrated. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

Example 1

Obtaining a toughened compound: uniformly mixing PTW and ethylene butyl acrylate copolymer, and adding the mixture into a torque rheometer to mix for 2-5 min; adding pure powder type polytetrafluoroethylene into a torque rheometer, continuously mixing for 2-5 min, taking materials, cooling and crushing to obtain the toughening compound, wherein the temperature of the torque rheometer is set to be 190 ℃, the rotating speed of a rotor is 80rpm, and the adding weight percentage of each toughening component is as follows: 31 percent of ethylene terpolymer component with epoxy functional groups, 62 percent of ethylene butyl acrylate copolymer component and 7 percent of pure powder type polytetrafluoroethylene component.

Preparing a PBT composite material: adding 85 parts of PBT resin, 15 parts of toughening compound, 0.3 part of compound of antioxidant 1010 and 168, 0.2 part of calcium montanate, 0.5 part of calcium stearate and 0.2 part of sodium dihydrogen phosphate into a high-speed mixer, and mixing at high speed for 2-4min to obtain a uniform mixed material;

and putting the obtained mixed material into a co-rotating parallel double-screw extruder, and melting, extruding and granulating to obtain the PBT composite material, wherein the processing temperature of each area of the double-screw extruder is as follows: the first zone is 230 ℃, the second zone is 250 ℃, the third zone is 260 ℃, the fourth zone is 260 ℃, the fifth zone is 250 ℃, the sixth zone is 240 ℃, the seventh zone is 240 ℃, the eighth zone is 240 ℃, the ninth zone is 250 ℃, the head is 260 ℃, the pressure of a vacuum pump is controlled to be above 0.06MPa, and the rotating speed is 400 r/min.

Example 2

Obtaining a toughened compound: the same as in example 1.

Preparing a PBT composite material: adding 80 parts of PBT resin, 20 parts of toughening compound, 0.3 part of compound of antioxidant 1010 and 168, 0.2 part of calcium montanate, 0.5 part of calcium stearate and 0.2 part of sodium dihydrogen phosphate into a high-speed mixer, and mixing at high speed for 2-4min to obtain a uniform mixed material;

and putting the obtained mixed material into a co-rotating parallel double-screw extruder, and melting, extruding and granulating to obtain the PBT composite material, wherein the processing temperature of each area of the double-screw extruder is as follows: the first zone is 230 ℃, the second zone is 250 ℃, the third zone is 260 ℃, the fourth zone is 260 ℃, the fifth zone is 250 ℃, the sixth zone is 240 ℃, the seventh zone is 240 ℃, the eighth zone is 240 ℃, the ninth zone is 250 ℃, the head is 260 ℃, the pressure of a vacuum pump is controlled to be above 0.06MPa, and the rotating speed is 400 r/min.

Example 3

Obtaining a toughened compound: uniformly mixing PTW and ethylene butyl acrylate copolymer, and adding the mixture into a torque rheometer to mix for 2-5 min; adding pure powder type polytetrafluoroethylene into a torque rheometer, continuously mixing for 2-5 min, taking materials, cooling and crushing to obtain the toughening compound, wherein the temperature of the torque rheometer is set to be 190 ℃, the rotating speed of a rotor is 80rpm, and the adding weight percentage of each toughening component is as follows: 30% of ethylene terpolymer with epoxy functional groups, 60% of ethylene butyl acrylate copolymer and 10% of pure powder polytetrafluoroethylene.

Preparing a PBT composite material: adding 85 parts of PBT resin, 15 parts of toughening compound, 0.3 part of compound of antioxidant 1010 and 168, 0.2 part of calcium montanate, 0.5 part of calcium stearate and 0.2 part of sodium dihydrogen phosphate into a high-speed mixer, and mixing at high speed for 2-4min to obtain a uniform mixed material;

and putting the obtained mixed material into a co-rotating parallel double-screw extruder, and melting, extruding and granulating to obtain the PBT composite material, wherein the processing temperature of each area of the double-screw extruder is as follows: the first zone is 230 ℃, the second zone is 250 ℃, the third zone is 260 ℃, the fourth zone is 260 ℃, the fifth zone is 250 ℃, the sixth zone is 240 ℃, the seventh zone is 240 ℃, the eighth zone is 240 ℃, the ninth zone is 250 ℃, the head is 260 ℃, the pressure of a vacuum pump is controlled to be above 0.06MPa, and the rotating speed is 400 r/min.

Comparative example 1

Obtaining a toughened compound: uniformly mixing PTW and pure powder polytetrafluoroethylene, adding the mixture into a torque rheometer, mixing for 2-5 min, taking materials, cooling and crushing to obtain the toughening composite, wherein the temperature of the torque rheometer is set to be 190 ℃, the rotating speed of a rotor is 80rpm, and the adding weight percentage of each toughening component is as follows: 93 percent of ethylene terpolymer component of epoxy functional group and 7 percent of pure powder type polytetrafluoroethylene component.

Preparing a PBT composite material: the same as in example 1.

Comparative example 2

Obtaining a toughened compound: uniformly mixing ethylene butyl acrylate copolymer and pure powder polytetrafluoroethylene, adding the mixture into a torque rheometer, mixing for 2-5 min, taking materials, cooling and crushing to obtain the toughening composite, wherein the temperature of the torque rheometer is set to be 190 ℃, the rotating speed of a rotor is 80rpm, and the adding weight percentage of each toughening component is as follows: 93 percent of ethylene butyl acrylate copolymer and 7 percent of pure powder type polytetrafluoroethylene.

Preparing a PBT composite material: the same as in example 1.

Comparative example 3

Obtaining a toughened compound: uniformly mixing PTW and ethylene butyl acrylate copolymer, adding the mixture into a torque rheometer, mixing for 2-5 min, taking materials, cooling and crushing to obtain the toughening compound, wherein the temperature of the torque rheometer is set to be 190 ℃, the rotating speed of a rotor is 80rpm, and the adding weight percentage of each toughening component is as follows: 35% of ethylene terpolymer with epoxy functional groups and 65% of ethylene butyl acrylate copolymer.

Preparing a PBT composite material: the same as in example 1.

Example 4

Obtaining a toughened compound: in the embodiment, the toughening components are added in the following weight percentage: PTW 20%, ethylene butyl acrylate copolymer 70%, pure powder polytetrafluoroethylene 10%, the temperature of the torque rheometer was set to 180 ℃, the rotor speed was 100rpm, and the other points were the same as in example 1.

Preparing a PBT composite material: adding 70 parts of PBT resin, 10 parts of toughening compound, 10760.05 parts of antioxidant, 1680.05 parts of antioxidant, NaV1010.1 parts, 0.3 part of ethylene bis stearamide and 0.1 part of sodium dihydrogen phosphate into a high-speed mixer, and mixing at high speed for 2-4min to obtain a uniform mixed material;

and putting the obtained mixed material into a co-rotating parallel double-screw extruder, and melting, extruding and granulating to obtain the PBT composite material, wherein the processing temperature of each area of the double-screw extruder is as follows: the first zone is 230 ℃, the second zone is 250 ℃, the third zone is 260 ℃, the fourth zone is 260 ℃, the fifth zone is 250 ℃, the sixth zone is 240 ℃, the seventh zone is 240 ℃, the eighth zone is 240 ℃, the ninth zone is 250 ℃, the head is 260 ℃, the pressure of a vacuum pump is controlled to be above 0.06MPa, and the rotating speed is 300 r/min.

Example 5

Obtaining a toughened compound: in the embodiment, the toughening components are added in the following weight percentage: PTW 40%, ethylene butyl acrylate copolymer 55%, pure powder polytetrafluoroethylene 5%, temperature of the torque rheometer was set to 200 ℃, rotor speed was 90rpm, and the other steps were the same as in example 1.

Preparing a PBT composite material: adding 75 parts of PBT resin, 25 parts of toughening compound, 10100.3 parts of antioxidant, 6260.2 parts of antioxidant, YN-5000.5 parts, 1.0 part of polyethylene wax and 0.5 part of sodium dihydrogen phosphate into a high-speed mixer, and mixing at high speed for 2-4min to obtain a uniform mixed material;

and putting the obtained mixed material into a co-rotating parallel double-screw extruder, and melting, extruding and granulating to obtain the PBT composite material, wherein the processing temperature of each area of the double-screw extruder is as follows: the first zone is 230 ℃, the second zone is 250 ℃, the third zone is 260 ℃, the fourth zone is 260 ℃, the fifth zone is 250 ℃, the sixth zone is 240 ℃, the seventh zone is 240 ℃, the eighth zone is 240 ℃, the ninth zone is 250 ℃, the head is 260 ℃, the pressure of a vacuum pump is controlled to be above 0.06MPa, and the rotating speed is 450 r/min.

Example 6

Obtaining a toughened compound: in the embodiment, the toughening components are added in the following weight percentage: PTW 40%, ethylene butyl acrylate copolymer 50%, pure powder polytetrafluoroethylene 10%, and the others were the same as in example 4.

Preparing a PBT composite material: the same as in example 4.

Test example

The PBT composite materials prepared in examples 1-3 and comparative examples 1-3 were subjected to the relevant performance tests, respectively, and the results are shown in Table 1.

TABLE 1 PBT COMPOSITE MATERIAL PERFORMANCE TEST RESULTS

Note: in table 1, the tensile strength is referred to standard ISO 527;

elongation at break ISO 527;

bending strength is according to ISO 178;

flexural modulus reference ISO 178;

the impact strength of the cantilever beam notch is according to ISO 180;

the melt flow length is the length of the injection molding spiral line.

As can be seen from the comparison results of the examples and the comparative examples in Table 1, the super-tough PBT material prepared by the material formula and the process has excellent impact strength and elongation at break and excellent processability. It is concluded from comparative examples 1-3 and examples 1-3 that with the synergistic addition of the third toughening component, a "fish-net-like" rubber network structure is successfully prepared, the impact strength and elongation at break of the material also undergo a "brittle-tough transition", which is dramatically improved, and the material has less fluidity loss. Meanwhile, the super-tough PBT material can be obtained by adding less composite toughening agent, so that the cost of the material is reduced.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.