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CN-122011699-A - Glass fiber modified PET flame-retardant composite material and preparation method thereof

CN122011699ACN 122011699 ACN122011699 ACN 122011699ACN-122011699-A

Abstract

The invention relates to the technical field of PET (polyethylene terephthalate), and discloses a glass fiber modified PET flame-retardant composite material and a preparation method thereof, wherein the glass fiber modified PET flame-retardant composite material comprises 100 parts of polyethylene terephthalate, 30-42 parts of glass fiber, 8-14 parts of polytetrafluoroethylene and 2-7 parts of fluorine-containing DOPO (polyethylene terephthalate) polyester, and the fluorine-containing DOPO polyester improves the compatibility of the polytetrafluoroethylene and PET, reduces the influence of the polytetrafluoroethylene on the mechanical properties of the PET, and ensures that the composite material maintains good tensile strength. The fluorine-containing DOPO polyester contains phosphate flame-retardant groups, has condensed phase flame-retardant property, plays a role in synergistic flame retardance with polytetrafluoroethylene anti-dripping agent, has a large limiting oxygen index, reaches a V-1 to V-0 grade in UL-94, and has excellent flame retardance.

Inventors

  • YANG FUHUA

Assignees

  • 浙江立德新型环保材料有限公司

Dates

Publication Date
20260512
Application Date
20260318

Claims (9)

  1. 1. The glass fiber modified PET flame-retardant composite material is characterized by comprising, by weight, 100 parts of polyethylene terephthalate, 30-42 parts of glass fibers, 8-14 parts of polytetrafluoroethylene and 2-7 parts of fluorine-containing DOPO polyester; The fluorine-containing DOPO polyester is prepared by the following steps of introducing nitrogen into a reaction bottle, adding a solvent, an acid-binding agent and 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stirring, adding 2, 2-bis (4-formylchlorophenyl) hexafluoropropane into an ice bath, stirring for reaction, adding water for dilution, filtering, washing a product, and drying to obtain the fluorine-containing DOPO polyester.
  2. 2. The glass fiber modified PET flame retardant composite of claim 1, wherein the solvent is N-methylpyrrolidone or N, N-dimethylformamide.
  3. 3. The glass fiber modified PET flame retardant composite of claim 1, wherein the ratio of the acid binding agent, 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-bis (4-formylchlorophenyl) hexafluoropropane, is (2-2.4) mol (1.02-1.06) mol to 1mol.
  4. 4. The glass fiber modified PET flame retardant composite of claim 3, wherein the acid binding agent is triethylamine or pyridine.
  5. 5. The glass fiber modified PET flame retardant composite of claim 1, wherein the temperature during the stirring reaction is 70-90 ℃ and the reaction time is 6-10 hours.
  6. 6. The glass fiber modified PET flame-retardant composite material according to claim 1, wherein the 2, 2-bis (4-formylchlorophenyl) hexafluoropropane is prepared by adding thionyl chloride and 2, 2-bis (4-carboxyphenyl) hexafluoropropane into a reaction vessel, heating to 75-80 ℃, stirring, condensing, refluxing for 12-18 hours, concentrating under reduced pressure, and recrystallizing the product to obtain the 2, 2-bis (4-formylchlorophenyl) hexafluoropropane.
  7. 7. The glass fiber modified PET flame retardant composite material according to claim 6, wherein the ratio of sulfoxide chloride to 2, 2-bis (4-carboxyphenyl) hexafluoropropane is 1L (300-360) g.
  8. 8. A method for preparing the glass fiber modified PET flame-retardant composite material according to any one of claims 1 to 7, which is characterized in that the method comprises the steps of mixing polyethylene terephthalate, glass fiber, polytetrafluoroethylene and fluorine-containing DOPO polyester, extruding the mixture through a double-screw extruder, and granulating the mixture to obtain the glass fiber modified PET flame-retardant composite material.
  9. 9. The method for preparing the glass fiber modified PET flame-retardant composite material according to claim 8, wherein the temperature of each section of the double-screw extruder is 170-260 ℃, and the screw rotating speed is 40-100r/min.

Description

Glass fiber modified PET flame-retardant composite material and preparation method thereof Technical Field The invention relates to the technical field of PET, in particular to a glass fiber modified PET flame-retardant composite material and a preparation method thereof. Background Polyethylene terephthalate PET is a high-performance resin with high mechanical strength, large modulus, good high temperature resistance and biodegradability, and is widely applied to the aspects of fiber, packaging, electronic electric ‌, automobile manufacturing and the like. However, PET has poor flame retardance, serious molten drop phenomenon exists during combustion, scalding and secondary disasters can be caused, and flame retardance modification of PET is the important point of research. The PET flame retardant mainly comprises inorganic flame retardants such as antimony trioxide and the like, organic flame retardants such as phosphorus and nitrogen and the like, polytetrafluoroethylene has strong high-temperature resistance, can be depolymerized into small molecules preferentially at high temperature or during combustion, has no molten drop formation, is a common anti-dripping agent, and has important application in the aspect of flame retardant materials. However, the poor compatibility of the polytetrafluoroethylene and the PET can affect the mechanical strength of the PET, and the flame retardant property of the PET is difficult to be effectively improved by only adding the polytetrafluoroethylene. Disclosure of Invention The invention solves the problem of lower flame retardant property of PET material and maintains good mechanical strength. The technical scheme of the invention is that the preparation method of the glass fiber modified PET flame-retardant composite material comprises the following steps: (1) Adding thionyl chloride and 2, 2-bis (4-carboxyphenyl) hexafluoropropane into a reaction vessel, stirring for reaction, concentrating under reduced pressure, and recrystallizing the product in n-hexane to obtain 2, 2-bis (4-formylchlorophenyl) hexafluoropropane. The reaction formula is: 。 (2) Introducing nitrogen into a reaction bottle, adding a solvent, an acid-binding agent and 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, stirring, adding 2, 2-bis (4-formylchlorophenyl) hexafluoropropane into an ice bath, stirring for reaction, adding water for dilution, filtering, washing a product with water and ethanol, and drying to obtain the fluorine-containing DOPO polyester. The reaction formula is: 。 (3) And mixing polyethylene terephthalate, glass fiber, polytetrafluoroethylene and fluorine-containing DOPO polyester, extruding by a double-screw extruder, and granulating to obtain the glass fiber modified PET flame-retardant composite material. Further, the ratio of thionyl chloride to 2, 2-bis (4-carboxyphenyl) hexafluoropropane in (1) was 1L (300-360) g. Further, the temperature during the stirring reaction in (1) is 75-80 ℃, and the reaction time is 12-18h. Further, the solvent in (2) is N-methyl pyrrolidone or N, N-dimethylformamide. Further, the ratio of the acid-binding agent, 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 2-bis (4-formylchlorophenyl) hexafluoropropane in (2) was (2-2.4) mol (1.02-1.06) mol to 1mol. Further, the acid-binding agent in (2) is triethylamine or pyridine. Further, the temperature during the stirring reaction in (2) is 70-90 ℃, and the reaction time is 6-10h. Further, the amount of polyethylene terephthalate is 100 parts by weight, the glass fiber is 30-42 parts by weight, the polytetrafluoroethylene is 8-14 parts by weight, and the fluorine-containing DOPO polyester is 2-7 parts by weight. Further, the temperature of each section of the twin-screw extruder in the step (3) is 170-260 ℃, and the screw rotating speed is 40-100r/min. The invention has the beneficial technical effects that 10- (2, 5-dihydroxyphenyl) -9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 2, 2-bis (4-formylchlorophenyl) hexafluoropropane are polymerized to obtain fluorine-containing DOPO polyester, and then the fluorine-containing DOPO polyester is mixed with reinforcing agent glass fiber, polytetrafluoroethylene anti-dripping agent and polyethylene terephthalate to obtain the glass fiber modified PET flame-retardant composite material. The fluorine-containing DOPO polyester contains polyester molecular chains similar to PET, contains a plurality of fluorine-containing groups, has similar polarity to polytetrafluoroethylene, can play a role in compatibilizing PET and polytetrafluoroethylene, improves the compatibility of polytetrafluoroethylene and PET, reduces the influence of polytetrafluoroethylene on the mechanical properties of PET, and ensures that the composite material maintains good tensile strength. The fluorine-containing DOPO polyester contains phosphate flame-retardant groups, has condensed phase flame-retardant character