Search

CN-121991504-A - High-strength wear-resistant heat-conducting PA10T composite material and preparation method thereof

CN121991504ACN 121991504 ACN121991504 ACN 121991504ACN-121991504-A

Abstract

The invention discloses a high-strength wear-resistant heat-conducting PA10T composite material and a preparation method thereof, wherein the used composite reinforced chain extender consists of short carbon fiber powder and spherical nano-alumina, wherein the short carbon fiber powder is activated by MDI through covalent bond bridging surface. When the PA10T composite material is prepared, the composite reinforced chain extender and PA10T salt are mixed in a pre-polymerization stage, and in-situ polymerization is carried out. MDI reacts with the prepolymer end groups to achieve chain extension while carbon fibers and alumina are uniformly and firmly introduced into the PA10T matrix through chemical bonds, forming a strongly interfacial bonded multi-scale reinforcing network. The method has good process compatibility, the obtained material is synchronously and obviously improved in the aspects of tensile strength, impact toughness, heat resistance and the like, has excellent comprehensive performance, is suitable for the field of high-end engineering with strict requirements on materials, and is particularly suitable for the manufacturing fields of electronic appliances, automobiles and high-end equipment with strict requirements on heat dissipation, wear resistance and mechanical strength.

Inventors

  • ZHENG YUYING
  • Chen Dengya

Assignees

  • 福州大学

Dates

Publication Date
20260508
Application Date
20260325

Claims (9)

  1. 1. The preparation method of the high-strength wear-resistant heat-conducting PA10T composite material is characterized by comprising the following steps of: (1) 1, 10-diaminodecane, terephthalic acid, sodium hypophosphite serving as a catalyst and antioxidant 1010 are dispersed in deionized water by ultrasonic waves; (2) Transferring the dispersion liquid obtained in the step (1) into a high-temperature high-pressure reaction kettle, and stirring and reacting for 2 hours at 80 ℃ and 0.1MPa under the nitrogen atmosphere to obtain PA10T salt; (3) Heating for the second time under the condition of keeping stirring, heating to 240 ℃, and maintaining the pressure to 2.0-3.0 MPa for 4 hours; (4) Adding a composite reinforced chain extender into the reaction kettle, and continuously reacting for 2 hours at 240 ℃ and the pressure of 2.5 MPa; (5) And (3) decompressing and cooling the reaction kettle, placing the prepolymer into a glass culture dish, placing the glass culture dish into a high-temperature vacuum drying box, performing solid-phase tackifying for 4 hours, and then naturally cooling to normal temperature to obtain the high-strength wear-resistant heat-conducting PA10T composite material.
  2. 2. The preparation method of claim 1, wherein the raw materials comprise, by weight, 52 parts of 1, 10-diaminodecane, 50 parts of terephthalic acid, 2-8 parts of a composite reinforced chain extender, 0.1 part of sodium hypophosphite as a catalyst and 1 part of antioxidant 1010.
  3. 3. The preparation method according to claim 1, wherein the composite reinforced chain extender is formed by connecting 4,4' -diphenylmethane diisocyanate MDI, surface-activated carbon fibers and surface-activated spherical nano alumina through covalent bonds, wherein one isocyanate group of the MDI reacts with a reactive functional group on the surface of the carbon fibers, and the other isocyanate group reacts with hydroxyl groups on the surface of the alumina.
  4. 4. The preparation method according to claim 3, wherein the particle size of the spherical nano alumina is 30nm, the carbon fiber is chopped carbon fiber powder subjected to acid oxidation treatment, the diameter of a monofilament is 7 μm, the fineness is 300 meshes, the density is 1.75g/cm, and the carbon content is more than or equal to 95%.
  5. 5. The preparation method of claim 3, wherein the composite reinforced chain extender adopts a synthesis process of a two-step coupling method, and specifically comprises the following steps: 1) Performing acid oxidation treatment on the chopped carbon fiber powder, and performing heat treatment and dispersion treatment on the spherical nano-alumina to obtain surface-activated carbon fibers and surface-activated spherical nano-alumina respectively; 2) Reacting the surface activated carbon fiber with MDI in an organic solvent at a first temperature in the presence of an inert atmosphere and a catalyst to obtain an intermediate CF-MDI; 3) Adding spherical nano alumina with activated surface into the reaction system in the step 2), and continuing to react for 6 hours at 80 ℃ until the isocyanate groups of the MDI are completely reacted; 4) And (3) separating, washing and drying the solid product obtained in the step (3) to obtain the composite reinforced chain extender CF-MDI-Al 2 O 3 .
  6. 6. The method according to claim 5, wherein the catalyst in step 2) is dibutyltin dilaurate, and the solvent is anhydrous N, N-dimethylformamide.
  7. 7. The method according to claim 5, wherein the first temperature in the step 2) is 60 ℃, the reaction time is 6 hours, and nitrogen is used as the inert gas.
  8. 8. The method according to claim 5, wherein the solid is washed with acetone, which is an anhydrous solvent, a plurality of times to remove surface impurities in step 4).
  9. 9. A high strength abrasion resistant thermally conductive PA10T composite material made according to the method of any one of claims 1-8.

Description

High-strength wear-resistant heat-conducting PA10T composite material and preparation method thereof Technical Field The invention relates to the technical field of polymer composite materials, in particular to a composite material which takes semi-aromatic high temperature resistant polyamide PA10T as a matrix and is synergistically modified by multi-component and multi-scale fillers and has high strength, excellent wear resistance and high heat conduction performance, and a preparation method thereof. Background Poly (p-phenylene terephthalamide) (PA 10T) is a semi-aromatic high temperature resistant polyamide with excellent properties. The monomer decanediamine is derived from renewable resource castor oil, and has green and environment-friendly characteristics. The PA10T molecular chain contains both rigid benzene ring and flexible methylene chain segment, so that the PA has the advantages of high melting point (about 316 ℃), excellent heat resistance, good dimensional stability, low water absorption, chemical solvent resistance and the like, and has wide application prospect in the fields of electronics, electricity, automobiles, aerospace and the like. However, pure PA10T resins have some limitations, firstly, the melting point is close to the thermal decomposition temperature, the processing window is narrow, thermal degradation is easy to occur during melt processing, secondly, as typical engineering plastics, the impact toughness of the pure resins needs to be improved, furthermore, the heat conductivity coefficient of the pure PA10T resins is low, the urgent requirements of modern high-power electronic devices on the heat dissipation performance of materials cannot be met, and finally, the wear resistance of the pure PA10T resins still needs to be enhanced for moving part applications. Chain extenders are effective means of increasing the molecular weight of polymers, 4' -diphenylmethane diisocyanate (MDI) being one of the commonly used chain extenders, the isocyanate groups (-NCO) of which can react with the amino-or carboxyl-terminated groups of the polymer to effect chain extension. However, MDI alone can only increase the molecular weight, and cannot introduce additional reinforcing functions. In order to overcome the above disadvantages, modification studies on PA10T have become a hot spot. The main modification method comprises copolymerization modification and blending modification. The copolymerization modification is to introduce a third monomer (such as adipic acid, sebacic acid, isophthalic acid and the like) to break the regularity of a molecular chain, so that the melting point is reduced, the processing window is widened, and the toughness is improved. The blending modification is to introduce fillers such as fibers, particles and the like in a physical blending mode so as to improve the specific performance of the fiber, the particles and the like. However, the prior art tends to focus on improvements in single performance. For example, the addition of a large amount of thermally conductive filler (such as alumina) can improve the thermal conductivity, but can impair the mechanical properties (particularly impact toughness) and processing flowability of the material, while the addition of carbon fiber can greatly enhance the mechanical properties, but the improvement of the thermal conductivity is limited, and the performance may be suboptimal due to poor interface bonding. Therefore, the development of a novel modifier which can realize chain extension and nano reinforcement simultaneously and form strong interface combination with a matrix has important significance for preparing the ultra-high performance PA10T composite material. The invention aims to add a composite reinforced chain extender in the process of exquisite synthesis of high-strength PA10T, wherein the composite reinforced chain extender is composed of chopped carbon fiber powder and spherical nano-alumina, wherein the chopped carbon fiber powder is activated by bridging the surface of 4,4' -diphenylmethane diisocyanate (MDI) through a covalent bond. When the PA10T composite material is prepared, the composite reinforced chain extender and PA10T salt are mixed in a pre-polymerization stage, and in-situ polymerization is carried out. The MDI and the prepolymer end groups react to realize chain extension, and simultaneously, carbon fibers and aluminum oxide are uniformly and firmly introduced into the PA10T matrix through chemical bonds, so that a multi-scale reinforced network with strong interface bonding is formed, and the technical problem is solved. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a high-strength wear-resistant heat-conducting PA10T composite material with excellent comprehensive performance and a preparation method thereof. The material realizes balance and promotion of mechanical property, heat conduction property and wear resistance through multi-