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CN-121975315-A - High-toughness flame-retardant PA66 composite material and preparation method thereof

CN121975315ACN 121975315 ACN121975315 ACN 121975315ACN-121975315-A

Abstract

The invention discloses a high-toughness flame-retardant PA66 composite material and a preparation method thereof, belongs to the technical field of high polymer materials, and aims to solve the technical contradiction that the toughness and the processing performance of the traditional flame-retardant PA66 are greatly reduced due to the fact that a large amount of solid flame retardant is added, and the flame retardant efficiency is weakened by a toughening agent. According to the invention, a phosphorus-containing flame-retardant structural unit is introduced into a PA66 main chain, and a chemically bonded continuous phase-disperse phase interface network structure is constructed in the melt reaction extrusion process by combining a reactive compatibilizer and a synergistic elastomer. Based on the cooperative regulation and control of the molecular layer surface and the interface layer surface, the composite material provided by the invention can meet the high-grade flame-retardant requirement, has a higher limiting oxygen index, and simultaneously still maintains excellent mechanical properties, and particularly shows remarkably improved impact toughness under the low-temperature condition, so that the cooperative optimization and balance of the flame retardant property and the mechanical toughness are effectively realized.

Inventors

  • HU LEI
  • XU XUHUI
  • CHEN YANG
  • Fang Ruzhi
  • CHEN FENG

Assignees

  • 浙江研一特材有限公司

Dates

Publication Date
20260505
Application Date
20260129

Claims (10)

  1. 1. The high-toughness flame-retardant PA66 composite material comprises base resin, an elastomer and an additive, and is characterized by comprising, by weight, 65-80 parts of intrinsic flame-retardant PA66 resin, 4-8 parts of a reactive compatibilizer, 10-20 parts of a synergistic elastomer, 0.4-0.8 part of an antioxidant and 0.1-0.3 part of a lubricant, wherein a phosphorus-containing flame-retardant structural unit DOPO-AIPA is copolymerized in the main chain of the intrinsic flame-retardant PA66 resin, the reactive compatibilizer is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer, the synergistic elastomer is a segmented polyether amide elastomer PA12-PTMEG, the hard segment of the synergistic elastomer is composed of a polyamide 12 segment, the soft segment of the synergistic elastomer is composed of a polytetramethylene ether glycol segment, the intrinsic flame-retardant PA66 resin is used as a continuous phase, and the synergistic elastomer is used as a disperse phase to form a continuous phase-disperse phase interface network structure at an interface through chemical bonding.
  2. 2. The high-toughness flame-retardant PA66 composite material according to claim 1, wherein the phosphorus-containing flame-retardant structural unit DOPO-AIPA is 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, and is introduced into a phosphorus-containing aromatic diacid structure formed by methylene bridging in a 5-amino isophthalic acid molecule, and the structure is shown as follows: 。
  3. 3. The high-toughness flame-retardant PA66 composite material according to claim 2, wherein the preparation method of the phosphorus-containing flame-retardant structural unit DOPO-AIPA is characterized in that 5-amino isophthalic acid is dissolved in absolute ethyl alcohol, nitrogen is replaced and protected, stirring is carried out, heating is carried out to 60 ℃, paraformaldehyde is added, stirring is carried out for 30 minutes, 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide is added, then, heating is carried out to a reflux state, reflux reaction is carried out for 5 hours, cooling is carried out to room temperature after reaction is finished, suction filtration is carried out, filter cakes are collected, washing is carried out, and drying is carried out, thus obtaining the product.
  4. 4. A high toughness flame retardant PA66 composite as described in claim 3 wherein said 5-amino isophthalic acid, said paraformaldehyde, and said 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide are present in a molar ratio of 1:1.1:1.
  5. 5. The high-toughness flame-retardant PA66 composite material according to claim 1, wherein the preparation method of the intrinsic flame-retardant PA66 resin is characterized in that adipic acid, phosphorus-containing flame-retardant structural unit DOPO-AIPA and hexamethylenediamine are stirred and dissolved in deionized water at 60 ℃, the pH value of a system is regulated to 7.5, nitrogen is replaced and protected, the temperature of the system is increased to 220 ℃, the pressure is controlled to 2.0MPa, the pressure is maintained for 2 hours, the temperature is continuously increased to 270 ℃, the pressure is reduced and reduced to minus 0.08MPa, the reaction is continued for 40 minutes, after the reaction is finished, the nitrogen is filled into the system to be normal pressure, the melted polymer is extruded, water-cooled to form strips, granulated and dried, and the product is obtained.
  6. 6. A high toughness flame retardant PA66 composite material as described in claim 5 wherein said adipic acid, said phosphorus containing flame retardant structural unit DOPO-AIPA, and said hexamethylenediamine are present in a molar ratio of 3.55:0.45:4.
  7. 7. The high-toughness flame-retardant PA66 composite material according to claim 1, wherein the antioxidant is a hindered phenol antioxidant and a phosphite antioxidant, the weight ratio of the hindered phenol antioxidant to the phosphite antioxidant is 1:1, and the lubricant is a fatty acid amide lubricant or a wax lubricant.
  8. 8. A method for preparing a high toughness flame retardant PA66 composite material according to any one of claims 1-7, comprising the steps of: S1, adding a dried ethylene-methyl acrylate-glycidyl methacrylate terpolymer, PA12-PTMEG, a hindered phenol antioxidant, a phosphite antioxidant and a lubricant into a pre-mixer for 3 minutes, then adding an intrinsic flame-retardant PA66 resin, and continuously mixing for 2 minutes to obtain a uniform mixture; And S2, carrying out reactive extrusion on the mixture, carrying out water-cooling bracing and granulating on the extrudate, and carrying out annealing treatment on the obtained particles to finally obtain the high-toughness flame-retardant PA66 composite material.
  9. 9. The method for preparing the high-toughness flame-retardant PA66 composite material according to claim 8, wherein the drying treatment method in the step S1 is that the air drying is carried out for 4 hours at 50 ℃, the hindered phenol antioxidant comprises an antioxidant 1098, an antioxidant 1010, an antioxidant 1076 or an antioxidant 245, the phosphite antioxidant comprises an antioxidant 168, an antioxidant 626 or an antioxidant 618, and the lubricant comprises ethylene bisstearamide, oleamide, erucamide or montan wax and polyethylene wax.
  10. 10. The method for preparing a high-toughness flame-retardant PA66 composite material according to claim 8, wherein the reaction extrusion condition in the step S2 is that the temperature is controlled to be 230-260 ℃ and the rotating speed is controlled to be 300-400rpm, and the annealing treatment condition is that vacuum treatment is carried out for 3 hours at 100 ℃.

Description

High-toughness flame-retardant PA66 composite material and preparation method thereof Technical Field The invention belongs to the technical field of high polymer materials, and particularly relates to a high-toughness flame-retardant PA66 composite material and a preparation method thereof. Background Polyamide 66 (PA 66) is widely used in the fields of electronics, electrical, traffic, engineering structural members, and the like due to its excellent mechanical properties, heat resistance, and processability. With the continuous improvement of the cooperative requirements of the high-grade flame retardant property and the high toughness of the material in the application field, the traditional PA66 material has difficulty in meeting the related use requirements at the same time. The existing flame retardant modification of PA66 is usually realized by adding flame retardants, such as red phosphorus, melamine salt, brominated flame retardants or halogen-free metal salt flame retardants such as diethyl aluminum phosphinate, wherein the red phosphorus and brominated flame retardants have migration and precipitation and environmental health risks, and the halogen-free metal salt flame retardants often need higher filling amount, and the mechanical property and processing fluidity of the materials are easily and obviously damaged. In order to make up for the weakening of toughness by flame retardant modification, polyolefin elastomers are often introduced in industry for toughening, but the addition of the organic phase weakens the efficiency of a flame retardant system, and further the consumption of a flame retardant is required to be further improved, so that a countermeasure relation which is difficult to reconcile between the flame retardant property and the mechanical property is formed. The Chinese patent CN119320554A discloses a high-toughness flame-retardant PA66 composite material for connectors and a preparation method thereof, and the core technology is characterized in that a styrene block copolymer, a polyolefin elastomer or ethylene propylene diene monomer, maleic anhydride and an initiator are grafted and modified and then used as a carrier, brominated polystyrene, organic silicon resin and a flame-retardant synergist are coated to prepare flame-retardant master batches, and then the flame-retardant master batches and a PA66 matrix are mixed and granulated. In summary, the existing flame-retardant PA66 technical route is difficult to realize the requirements of high-grade flame retardance and high toughness simultaneously on the premise of not obviously sacrificing mechanical properties and processability. Therefore, developing a novel PA66 material system with excellent toughness and flame retardant property becomes a key technical problem to be solved in the field. Disclosure of Invention The invention aims to solve the technical contradiction that the toughness and the processing performance of the traditional flame-retardant PA66 are greatly reduced due to the addition of a large amount of solid flame retardant, and the flame-retardant efficiency is weakened by the toughening agent. The specific technical scheme is as follows: The high-toughness flame-retardant PA66 composite material comprises, by weight, 65-80 parts of an intrinsic flame-retardant PA66 resin, 4-8 parts of a reactive compatibilizer, 10-20 parts of a synergistic elastomer, 0.4-0.8 part of an antioxidant and 0.1-0.3 part of a lubricant, wherein a phosphorus-containing flame-retardant structural unit DOPO-AIPA is copolymerized in the main chain of the intrinsic flame-retardant PA66 resin, the reactive compatibilizer is an ethylene-methyl acrylate-glycidyl methacrylate terpolymer, the synergistic elastomer is a segmented polyether amide elastomer PA12-PTMEG, the hard segment of the synergistic elastomer is composed of a polyamide 12 segment, the soft segment of the synergistic elastomer is composed of a polytetramethylene ether glycol segment, the intrinsic flame-retardant PA66 resin is used as a continuous phase, and the synergistic elastomer is used as a disperse phase to form a continuous phase-disperse phase interface network structure at an interface through chemical bonding. Further, the phosphorus-containing flame retardant structural unit DOPO-AIPA is a phosphorus-containing aromatic diacid structure formed by introducing 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide into 5-amino isophthalic acid molecules through methylene bridging, and the structure is shown as follows: 。 The preparation method of the phosphorus-containing flame-retardant structural unit DOPO-AIPA comprises the steps of dissolving 5-amino isophthalic acid in absolute ethyl alcohol, replacing nitrogen, protecting nitrogen, stirring and heating to 60 ℃, adding paraformaldehyde, stirring for 30 minutes, adding 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, heating to a reflux state, carrying out reflux reaction for 5 hours, cooling to room tem