A high-rigidity cold-resistant and super-tough PBT composite material and its preparation method

Abstract

The present invention relates to a high-rigidity cold-resistant and super-tough PBT composite material and a preparation method thereof, wherein the product comprises 75-85 parts of PBT, 15-25 parts of toughening agent, 0.5-3 parts of chain extender and 0-1.5 parts of auxiliary agent by weight; the toughening agent is a copolymer of organosiloxane, acrylic rubber, methyl methacrylate and glycidyl methacrylate; the toughening agent has a core-shell structure, the outer shell is methyl methacrylate and glycidyl methacrylate, the inner core is organosiloxane and acrylic rubber; the chain extender is an epoxy resin chain extender; the preparation method comprises mixing the components by weight ratio, and then extruding and granulating the high-rigidity cold-resistant and super-tough PBT composite material by a twin-screw extruder, wherein the extrusion temperature of the twin-screw extruder is 220-240°C. The method of the present invention is simple, and the product of the present invention has the characteristics of high rigidity, cold resistance and super-toughness.

Description

Technical Field

[0001] The invention belongs to the technical field of polymer materials and relates to a high-rigidity, cold-resistant and ultra-tough PBT composite material and a preparation method thereof. Background Art

[0002] PBT (polybutylene terephthalate) is a semi-crystalline linear saturated polyester, which is widely used in the fields of electronics, automobile industry, machinery, instrumentation and household appliances due to its excellent heat resistance, chemical resistance, electrical properties and processing performance. Pure PBT resin is relatively brittle and sensitive to notches. The plastic modification industry generally improves it by adding rubber toughening agents.

[0003] Arkema (SK) AX8900 and DuPont (Dow) PTW are more commonly used in the market to toughen PBT materials. This copolymer of ethylene-acrylate-glycidyl methacrylate does have a good toughening effect on PBT, mainly at room temperature, the toughening effect is obvious, but it has a great impact on the rigidity and heat resistance of the composite material. Patent CN102002215B proposes to use a toughening system of PE grafted with maleic anhydride, MBS, and AX8900 to improve the toughness of PBT, in which the compatibility of maleic anhydride functional groups with PBT is not good, and MBS is mainly used as a toughening agent for PC or PC alloys, and has limited toughening effect in pure PBT. AX8900 has a good toughening effect on PBT at room temperature, but it is limited at low temperatures and will significantly reduce the rigidity of the composite material. Patent CN102977561B proposes a core-shell structure toughener compounded with ABS grafted with maleic anhydride to improve the toughness of polytrimethylene terephthalate (PTT). Although a certain strength and rigidity are maintained, the functional group of maleic anhydride has limited compatibility with PTT, and the toughening effect is not high. The notched impact strength is less than 10KJ / m 2 . Summary of the invention

[0004] The purpose of the present invention is to solve the problems existing in the prior art and to provide a high-rigidity cold-resistant and super-tough PBT composite material and a preparation method thereof.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] A high-rigidity, cold-resistant and super-tough PBT composite material, comprising, by weight, 75-85 parts of PBT, 15-25 parts of a toughening agent, 0.5-3 parts of a chain extender and 0-1.5 parts of an auxiliary agent;

[0007] The toughening agent is a copolymer of organic siloxane, acrylic rubber, methyl methacrylate (MMA) and glycidyl methacrylate (GMA); the toughening agent has a core-shell structure, the outer shell is methyl methacrylate and glycidyl methacrylate, and the inner core is organic siloxane and acrylic rubber;

[0008] The chain extender is an epoxy resin chain extender.

[0009] As the preferred technical solution:

[0010] The high-rigidity, cold-resistant and super-tough PBT composite material has a tensile strength of 32.1-45.1 MPa, a flexural strength of 42.1-59.8 MPa, a flexural modulus of 1380-1705 MPa, and a notched impact strength of 48.2-88.6 KJ / m 2 , -40℃ notched impact strength is 9.5~19.3KJ / m 2 , the heat deformation temperature is 90.2~106.1℃.

[0011] As described above, a high-rigidity, cold-resistant and super-tough PBT composite material has a relative viscosity of PBT of more than 1.2. The higher the viscosity of PBT, the longer the molecular chain, the easier it is for the molecules to entangle with each other, the higher the toughness, and the better the toughening effect.

[0012] In the high-rigidity, cold-resistant and super-tough PBT composite material as described above, the weight portion of the additive is 0.6-1.5 parts.

[0013] The high-rigidity, cold-resistant and super-tough PBT composite material as described above, wherein the auxiliary agent is an antioxidant and / or a lubricant.

[0014] The present invention also provides a method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material as described in any of the above items, wherein the components are mixed according to a weight ratio, and then extruded and granulated by a twin-screw extruder to obtain a high-rigidity, cold-resistant and super-tough PBT composite material, wherein the extrusion temperature of the twin-screw extruder is 220-240°C;

[0015] The design of extrusion temperature mainly considers the viscosity of the material after melting. The PBT raw material is selected to have high viscosity, and the added toughening agent and chain extender have high reactivity, which will further increase the viscosity of the PBT melt. Therefore, the processing melting section temperature must be higher than the melting point of PBT (225°C) to ensure uniform dispersion of the various components of the melt.

[0016] Glycidyl methacrylate (GMA) and epoxy chain extender react with the carboxyl end groups of PBT at high temperature as follows:

[0017]

[0018] Glycidyl methacrylate (GMA) and epoxy chain extender react with the hydroxyl end groups of PBT at high temperature as follows:

[0019]

[0020] As the preferred technical solution:

[0021] In the method described above, the rotation speed of the twin-screw extruder is 400-450 rpm.

[0022] Beneficial Effects

[0023] (1) A high-rigidity, cold-resistant and super-tough PBT composite material of the present invention uses a copolymer as a toughening agent to present a core-shell structure, wherein organic siloxane and acrylic rubber are the core of the toughening agent to improve the toughness and low-temperature resistance of the composite material; the glass transition temperature (Tg) of the organic siloxane can reach -120°C, which can provide the composite material with excellent impact resistance and cold resistance; methyl methacrylate grafted glycidyl methacrylate is used as the shell part to provide compatibility with PBT; wherein glycidyl methacrylate can link multiple PBT macromolecules together through functional epoxy groups to form radial or network-shaped stress concentration points, which can simultaneously improve the impact performance and rigidity of the composite material;

[0024] (2) In the preparation process of a high-rigidity, cold-resistant and super-tough PBT composite material of the present invention, an epoxy resin-based chain extender is used. The epoxy group, the active group of the chain extender, can easily react with the terminal carboxyl group of PBT to form a "bridge" between two or more macromolecular chains, extending the linear PBT macromolecules into a network or branched structure, and forming an interconducting network structure with the stress point network of the spherical toughening agent, which can further increase the rigidity and toughness of the composite material. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0026] The detection methods for the relevant properties of the high-rigidity, cold-resistant and super-tough PBT composite materials prepared in the following embodiments and comparative examples are as follows:

[0027] The prepared composite material was dried in a blast oven at 110°C for more than 4 hours, and injection molded into standard specimens using an injection molding machine; the injection molded standard specimens were placed at a relative humidity of 50% and 23°C for at least 24 hours and then subjected to the following tests:

[0028] Tensile strength test method: refer to ISO 527-2 method for testing, where the tensile speed is 50mm / min;

[0029] Testing method for flexural strength and flexural modulus: Test according to ISO 178 method, where the test speed is 2mm / min;

[0030] Notched impact strength test method: refer to ISO 179 / 1eA method for testing, where the notch type is A-type notch and the pendulum energy is 2J;

[0031] -40℃ notched impact strength test method: Before testing, the sample is treated at -40℃ for at least 4 hours, and the test is carried out according to ISO 179 / 1eA method, where the notch type is A-type notch and the pendulum energy is 2J;

[0032] Testing method of heat deformation temperature: Test according to ISO 75-2 method, where the load is 0.45 MPa and the heating rate is 120°C / h.

[0033] Example 1

[0034] A method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material, the specific steps are as follows:

[0035] (1) Prepare raw materials:

[0036] Prepare 85 parts of PBT (manufacturer is Sinopec Yizheng Chemical Fiber Co., Ltd., brand GL236), 15 parts of toughening agent (manufacturer is Japan Mitsui Company, brand S-2200), 0.5 parts of chain extender (manufacturer is BASF, brand ADR 4468), 0.2 parts of antioxidant 1010 (manufacturer is BASF), 0.2 parts of antioxidant 168 (manufacturer is BASF), and 0.2 parts of lubricant (manufacturer is Italy Faki Company, brand AHS) by weight;

[0037] (2) Preparation of high rigidity, cold-resistant and super-tough PBT composite materials:

[0038] After mixing the components according to the weight ratio, the high-rigidity, cold-resistant and super-tough PBT composite material is obtained by extrusion and granulation through a twin-screw extruder, wherein the rotation speed of the twin-screw extruder is 400 rpm, and the extrusion temperatures of the first zone to the tenth zone of the twin-screw extruder are 220°C, 240°C, 240°C, 240°C, 235°C, 235°C, 235°C, 230°C and 225°C respectively.

[0039] The final high-rigidity, cold-resistant and super-tough PBT composite material has a tensile strength of 45.1MPa, a flexural strength of 59.8MPa, a flexural modulus of 1705MPa, and a notched impact strength of 48.2KJ / m2 , -40℃ notched impact strength is 9.5KJ / m 2 , the heat deformation temperature is 106.1℃.

[0040] Comparative Example 1

[0041] A method for preparing a composite material is basically the same as that in Example 1, except that 2.5 parts of the chain extender in Example 1 are used to replace the original 15 parts of the toughening agent in Example 1 (i.e., no toughening agent is added in Comparative Example 1) during the preparation process, that is, the chain extender in Comparative Example 1 is 3 parts in total, and the amount of chain extender added cannot be higher, otherwise it cannot be processed.

[0042] The composite material prepared by the method of this comparative example has a notched impact strength of 5.5 KJ / m 2 , -40℃ notched impact strength is 3.5KJ / m 2 .

[0043] By comparison, it can be seen that the notched impact strength of Comparative Example 1 is significantly lower than that of Example 1, because no toughening agent is added in Comparative Example 1.

[0044] Comparative Example 2

[0045] A method for preparing a composite material is basically the same as that of Example 1, except that 0.5 parts of the toughening agent of Example 1 are used to replace the original 0.5 parts of the chain extender of Example 1 during the preparation process (ie, no chain extender is added in Comparative Example 2).

[0046] The composite material prepared by the method of this comparative example has a tensile strength of 43.9 MPa, a flexural strength of 58.2 MPa, a flexural modulus of 1650 MPa, and a notched impact strength of 45.1 KJ / m 2 , -40℃ notched impact strength is 8.9KJ / m 2 , the heat deformation temperature is 104.9℃.

[0047] Compared with Example 1, the mechanical strength and heat resistance of the composite material of Comparative Example 2 are decreased to a certain extent. This is because without the chain extender, the molecular weight of PBT is low, resulting in a weak interpenetrating network structure and reduced overall performance.

[0048] Example 2

[0049] A method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material, the specific steps are as follows:

[0050] (1) Prepare raw materials:

[0051] Prepare 82 parts of PBT (manufacturer is Sinopec Yizheng Chemical Fiber Co., Ltd., brand GL236), 18 parts of toughening agent (manufacturer is Japan Mitsui Company, brand S-2200), 1 part of chain extender (manufacturer is BASF, brand ADR4468), 0.2 parts of antioxidant 1010 (manufacturer is BASF), 0.2 parts of antioxidant 168 (manufacturer is BASF), and 0.2 parts of lubricant (manufacturer is Italy Faki Company, brand AHS) by weight;

[0052] (2) Preparation of high rigidity, cold-resistant and super-tough PBT composite materials:

[0053] After mixing the components according to the weight ratio, the high-rigidity, cold-resistant and super-tough PBT composite material is obtained by extrusion and granulation through a twin-screw extruder, wherein the rotation speed of the twin-screw extruder is 400 rpm, and the extrusion temperatures of the first zone to the tenth zone of the twin-screw extruder are 220°C, 240°C, 240°C, 240°C, 235°C, 235°C, 235°C, 230°C and 225°C respectively.

[0054] The final high-rigidity, cold-resistant and super-tough PBT composite material has a tensile strength of 43.6MPa, a flexural strength of 57.9MPa, a flexural modulus of 1685MPa, and a notched impact strength of 52.1KJ / m 2 , -40℃ notched impact strength is 10.4KJ / m 2 , the heat deformation temperature is 102.4℃.

[0055] Example 3

[0056] A method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material, the specific steps are as follows:

[0057] (1) Prepare raw materials:

[0058] Prepare 80 parts of PBT (manufacturer is Sinopec Yizheng Chemical Fiber Co., Ltd., brand GL236), 20 parts of toughening agent (manufacturer is Japan Mitsui Company, brand S-2200), 1 part of chain extender (manufacturer is BASF, brand ADR4468), 0.2 parts of antioxidant 1010 (manufacturer is BASF), 0.2 parts of antioxidant 168 (manufacturer is BASF), and 0.2 parts of lubricant (manufacturer is Italy Faji Company, brand AHS) by weight;

[0059] (2) Preparation of high rigidity, cold-resistant and super-tough PBT composite materials:

[0060] After mixing the components according to the weight ratio, the high-rigidity, cold-resistant and super-tough PBT composite material is obtained by extrusion and granulation through a twin-screw extruder, wherein the rotation speed of the twin-screw extruder is 400 rpm, and the extrusion temperatures of the first zone to the tenth zone of the twin-screw extruder are 220°C, 240°C, 240°C, 240°C, 235°C, 235°C, 235°C, 230°C and 225°C respectively.

[0061] The final high-rigidity, cold-resistant and super-tough PBT composite material has a tensile strength of 39.4MPa, a flexural strength of 51.9MPa, a flexural modulus of 1555MPa, and a notched impact strength of 60.2KJ / m 2 , -40℃ notched impact strength is 12.5KJ / m 2 , the heat deformation temperature is 98.4℃.

[0062] Comparative Example 3

[0063] A method for preparing a composite material is basically the same as that of Example 3, except that a toughening agent (manufactured by Arkema, France, with a brand name of AX8900) is used to replace the original toughening agent (manufactured by Mitsui, Japan, with a brand name of S-2200) during the preparation process.

[0064] The composite material prepared by the method of this comparative example has a tensile strength of 35.3 MPa, a flexural strength of 46.3 MPa, a flexural modulus of 1260 MPa, and a notched impact strength of 74.3 KJ / m 2 , -40℃ notched impact strength is 7.1KJ / m 2 , the heat deformation temperature is 83.5℃.

[0065] Compared with Example 3, Comparative Example 3 has higher room temperature notched impact strength, but the strength, rigidity, low temperature impact and heat deformation temperature are significantly reduced. This is because the rubber effective content of AX8900 is higher, and the room temperature toughness is better improved, but its Tg is higher than that of the organosilicon core-shell toughening agent used in the present invention, so the low temperature impact is significantly lower, and because of its high rubber content, the strength, rigidity and heat deformation temperature of the composite material will also be seriously reduced.

[0066] Example 4

[0067] A method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material, the specific steps are as follows:

[0068] (1) Prepare raw materials:

[0069] Prepare 80 parts of PBT (manufacturer is Sinopec Yizheng Chemical Fiber Co., Ltd., brand GL236), 20 parts of toughening agent (manufacturer is Japan Mitsui Company, brand S-2200), 1.5 parts of chain extender (manufacturer is BASF, brand ADR4468), 0.2 parts of antioxidant 1010 (manufacturer is BASF), 0.2 parts of antioxidant 168 (manufacturer is BASF), and 0.2 parts of lubricant (manufacturer is Italy Faki Company, brand AHS) by weight;

[0070] (2) Preparation of high rigidity, cold-resistant and super-tough PBT composite materials:

[0071] After mixing the components according to the weight ratio, the high-rigidity, cold-resistant and super-tough PBT composite material is obtained by extrusion and granulation through a twin-screw extruder, wherein the rotation speed of the twin-screw extruder is 400 rpm, and the extrusion temperatures of the first zone to the tenth zone of the twin-screw extruder are 220°C, 240°C, 240°C, 240°C, 235°C, 235°C, 235°C, 230°C and 225°C respectively.

[0072] The final high-rigidity, cold-resistant and super-tough PBT composite material has a tensile strength of 40.1MPa, a flexural strength of 53.2MPa, a flexural modulus of 1605MPa, and a notched impact strength of 63.5KJ / m 2 , -40℃ notched impact strength is 13.1KJ / m 2 , the heat deformation temperature is 99.1℃.

[0073] Example 5

[0074] A method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material, the specific steps are as follows:

[0075] (1) Prepare raw materials:

[0076] Prepare 77 parts of PBT (manufacturer is Sinopec Yizheng Chemical Fiber Co., Ltd., brand GL236), 23 parts of toughening agent (manufacturer is Japan Mitsui Company, brand S-2200), 1 part of chain extender (manufacturer is BASF, brand ADR4468), 0.2 parts of antioxidant 1010 (manufacturer is BASF), 0.2 parts of antioxidant 168 (manufacturer is BASF), and 0.2 parts of lubricant (manufacturer is Italy Faki Company, brand AHS) by weight;

[0077] (2) Preparation of high rigidity, cold-resistant and super-tough PBT composite materials:

[0078] After mixing the components according to the weight ratio, the high-rigidity, cold-resistant and super-tough PBT composite material is obtained by extrusion and granulation through a twin-screw extruder, wherein the rotation speed of the twin-screw extruder is 400 rpm, and the extrusion temperatures of the first zone to the tenth zone of the twin-screw extruder are 220°C, 240°C, 240°C, 240°C, 235°C, 235°C, 235°C, 230°C and 225°C respectively.

[0079] The final high-rigidity, cold-resistant and super-tough PBT composite material has a tensile strength of 34.6MPa, a flexural strength of 45.4MPa, a flexural modulus of 1440MPa, and a notched impact strength of 80.2KJ / m 2 , -40℃ notched impact strength is 16.4KJ / m 2 , the heat deformation temperature is 93.1℃.

[0080] Comparative Example 4

[0081] A method for preparing a composite material is basically the same as that of Example 5, except that a toughening agent (manufactured by DuPont (Dow) Company, brand name PTW) is used to replace the original toughening agent (manufactured by Mitsui Co., Ltd. of Japan, brand name S-2200) during the preparation process.

[0082] The composite material prepared by the method of this comparative example has a tensile strength of 31.5 MPa, a flexural strength of 42.3 MPa, a flexural modulus of 1190 MPa, and a notched impact strength of 78.2 KJ / m 2 , -40℃ notched impact strength is 8.1KJ / m 2 , the heat deformation temperature is 78.5℃.

[0083] Compared with Example 5, the mechanical strength and heat deformation temperature of the composite material prepared in Comparative Example 4 are significantly reduced. This is because the compatibility of PTW with PBT is worse than that of the silicone core-shell toughening agent with PBT, and the Tg of PTW is higher than that of the silicone core-shell toughening agent, and the cold resistance improvement effect is poor.

[0084] Example 6

[0085] A method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material, the specific steps are as follows:

[0086] (1) Prepare raw materials:

[0087] Prepare 75 parts of PBT (manufacturer is Sinopec Yizheng Chemical Fiber Co., Ltd., brand GL236), 25 parts of toughening agent (manufacturer is Japan Mitsui Company, brand S-2200), 3 parts of chain extender (manufacturer is BASF, brand ADR4468), 0.5 parts of antioxidant 1010 (manufacturer is BASF), 0.5 parts of antioxidant 168 (manufacturer is BASF), and 0.5 parts of lubricant (manufacturer is Italy Faji Company, brand AHS) by weight;

[0088] (2) Preparation of high rigidity, cold-resistant and super-tough PBT composite materials:

[0089] After mixing the components according to the weight ratio, the high-rigidity, cold-resistant and super-tough PBT composite material is obtained by extrusion and granulation through a twin-screw extruder, wherein the rotation speed of the twin-screw extruder is 450 rpm, and the extrusion temperatures of the first zone to the tenth zone of the twin-screw extruder are 220°C, 240°C, 240°C, 240°C, 235°C, 235°C, 235°C, 230°C, and 225°C, respectively.

[0090] The final high-rigidity, cold-resistant and super-tough PBT composite material has a tensile strength of 32.1MPa, a flexural strength of 42.1MPa, a flexural modulus of 1380MPa, and a notched impact strength of 88.6KJ / m 2 , -40℃ notched impact strength is 19.3KJ / m 2 , the heat deformation temperature is 90.2℃.

Claims

1. A high-rigidity, cold-resistant and super-tough PBT composite material, characterized in that: By weight, it includes 75-85 parts of PBT, 15-25 parts of toughening agent, 0.5-3 parts of chain extender and 0-1.5 parts of auxiliary agent; The toughening agent is a copolymer of organic siloxane, acrylic rubber, methyl methacrylate and glycidyl methacrylate; the toughening agent has a core-shell structure, the outer shell is methyl methacrylate and glycidyl methacrylate, and the inner core is organic siloxane and acrylic rubber; The chain extender is an epoxy resin chain extender with the brand name ADR 4468 produced by BASF.

2. The high-rigidity, cold-resistant and super-tough PBT composite material according to claim 1, characterized in that: Tensile strength is 32.1-45.1MPa, flexural strength is 42.1-59.8MPa, flexural modulus is 1380-1705MPa, notched impact strength is 48.2-88.6KJ / m 2 , -40℃ notched impact strength is 9.5~19.3KJ / m 2 , the heat deformation temperature is 90.2~106.1℃.

3. The high-rigidity, cold-resistant and super-tough PBT composite material according to claim 1, characterized in that: The relative viscosity of PBT is 1.2 or more.

4. The high-rigidity, cold-resistant and super-tough PBT composite material according to claim 1, characterized in that: The weight proportion of the auxiliary agent is 0.6-1.5 parts.

5. A high-rigidity, cold-resistant and super-tough PBT composite material according to claim 4, characterized in that: The auxiliary agent is an antioxidant and / or a lubricant.

6. A method for preparing a high-rigidity, cold-resistant and super-tough PBT composite material according to any one of claims 1 to 5, characterized in that: After the components are mixed uniformly according to the weight ratio, the high-rigidity, cold-resistant and super-tough PBT composite material is prepared by extrusion and granulation through a twin-screw extruder, wherein the extrusion temperature of the twin-screw extruder is 220-240°C.

7. The preparation method according to claim 6, characterized in that: The speed of the twin-screw extruder is 400-450 rpm.

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