Flame-retardant chain-extended polybutylene terephthalate composition and preparation method thereof

Abstract

The invention discloses a flame-retardant chain-extended polybutylene terephthalate (PBT) composition and a preparation method of the PBT composition. The composition comprises the following raw materials by weight: 85%-90% of PBT, 9%-12% of aluminum diethylphosphinate, 0.4%-3% of polysiloxane containing an epoxy group in the side group, and 0.3%-0.7% of processing agent, wherein the processing agent is an antioxidant and an anti-dripping agent. According to the invention, the adopted polysiloxane containing the epoxy group in the side group and aluminum diethylphosphinate have obvious flame retardant synergistic effects on PBT. When the flame retardant property reaches to UL94V-0@1.6mm, the dose of aluminum diethylphosphinate is reduced by about 20% and the total flame retardant dose is reduced by about 12%. Under the premise of same flame retardant level, the mechanical properties of the composition provided by the invention is greatly improved.

Description

technical field [0001] The invention relates to a flame-retardant chain-extended polybutylene terephthalate composition, which belongs to the technical field of polymer material modification. Background technique [0002] Polybutylene terephthalate (PBT) is a thermoplastic semi-crystalline resin with excellent mechanical, electrical, chemical corrosion resistance, easy molding and low moisture absorption. It is an engineering plastic with excellent comprehensive properties. It is widely used in the fields of electronic and electrical, automobile industry, mechanical instrumentation, communication equipment and lighting components. However, PBT itself is easy to burn, and it will release a lot of heat when it burns, accompanied by a lot of smoke and toxic gases. Therefore, it is necessary to carry out flame-retardant modification of PBT, especially environmental protection flame-retardant modification, to reduce its potential fire hazard. It is a major problem that needs to ...

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Problems solved by technology

Aluminum diethylphosphinate has the advantages of lower density, better color, higher CTI value (up to 600V) and higher thermal stability (decomposition temperature > 350°C), etc. Its flame retardancy is not enhanced by PBT, and its quality is When the dosage is 13%, the flame retardant grade of PBT can reach UL94 V-01.6mm , but at this dosage, the mechanical properties of PBT such as tensile strength, bending strength, notched impact strength, etc. all have a large degree of decline, and the degree of decline is directly related to the dosage. The greater the dosage, the more obvious the impact on the mechanical properties; In addition, aluminum diethylphosphinate is currently very expensive, and the flame retardant cost is very high at this dosage, which has become a major obstacle to its practical application. Therefore, reducing its dosage is very important to maintain its mechanical properties and obtain practical applications. the meaning of

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