Polyamide composite and preparation method thereof
The present invention provides a polyamide composite, including the following components: 20 to 80 parts of a polyamide resin; 1 to 30 parts of a red phosphorus flame retardant; 0.01 to 10 parts of trimethallyl isocyanurate; and the polyamide composite has a cross-linked structure between polyamide molecules. By adding trimethallyl isocyanurate (TMAIC) for irradiation cross-linking treatment, and by the red phosphorus flame retardant, not only the polyamide composite can meet the needs of flame retardant, but also glow-wire ignition temperature (GWIT) and comparative tracking index (CTI) have been improved.
1 . A polyamide composite, consisting of the following components:
20 to 80 parts of a polyamide resin;
1 to 30 parts of a red phosphorus flame retardant;
0.01 to 10 parts of trimethallyl isocyanurate;
0 to 50 parts of a glass fiber; and
0 to 10 parts of an additive,
the polyamide composite has a cross-linked structure between polyamide molecules,
wherein the additive is selected from at least one of a colorant, a flexibilizer and an antioxidant.
2 . The polyamide composite according to claim 1 , wherein the polyamide resin is selected from polyamide resins obtained by polycondensation of diamine units and dicarboxylic acid units, polyamide resins obtained by ring-opening polymerization of lactam units, and polyamide resins obtained by self-condensation of aminocarboxylic acid units, or a polyamide copolymer resin obtained by copolymerizing at least two of the above-mentioned units constituting these polyamide resins.
3 . The polyamide composite according to claim 1 , wherein the red phosphorus flame retardant is selected from a red phosphorus powder or a red phosphorus flame retardant masterbatch.
4 . The polyamide composite according to claim 3 , wherein in the red phosphorus flame retardant masterbatch, red phosphorus accounts for 10% to 15% of a total weight, the red phosphorus flame retardant masterbatch is coated with a coating material, and the coating material is selected from at least one of inorganic hydroxide, phenolic resin, epoxy resin and melamine formaldehyde resin.
5 . The polyamide composite according to claim 1 , wherein the glass fiber is selected from at least one of an E-glass fiber, an H-glass fiber, an R,S-glass fiber, a D-glass fiber, a C-glass fiber and a quartz glass fiber.
6 . The polyamide composite according to claim 5 , wherein the glass fiber is selected from the E-glass fiber.
7 . The polyamide composite according to claim 5 , wherein the glass fiber has a diameter of 7 to 18 microns.
8 . A preparation method of the polyamide composite according to claim 1 , comprising the following steps: weighing the polyamide resin, the red phosphorus flame retardant, the trimethallyl isocyanurate, and the additive in proportion, and premixing in a high-speed mixer to obtain a premix, and then putting the premix into a twin-screw extruder for melt mixing, and extruding and granulating to obtain a workpiece; wherein, a screw length-diameter ratio of the twin-screw extruder is 40:1 to 48:1, a screw barrel temperature is 240° C. to 300° C., and a screw speed is 200 to 550 rpm; the extruded and granulated polyamide composite is injection-molded, with an injection moulding temperature of 270° C. to 300° C., and an injection moulding pressure of 55 to 100 MPa; and performing an irradiation cross-linking treatment to the workpiece, during the treatment, using an electron beam as an irradiation source, with an irradiation dose of 15 to 25 Mrad, to obtain the polyamide composite.
9 . The polyamide composite according to claim 6 , wherein the glass fiber has a diameter of 7 to 18 microns.