含磷硅阻燃PET的制备及其结构与性能研究

Preparation and structural properties of flame retardant PET containing phosphorus and silicon

在聚对苯二甲酸乙二醇酯（PET）中引入阻燃剂[（6-氧代-6H-二苯并[c,e][1,2]氧磷杂己环-6-基）甲基]丁二酸（DDP）,采用共聚法得到含磷阻燃PET,将其与纳米二氧化硅（Si O2）共混,得到Si O2质量分数为2%~8%含磷硅阻燃PET,并对其结构与性能进行了研究。结果表明：DDP阻燃剂以共聚形式引入到PET大分子链中,含磷阻燃PET随着DDP含量的增加其特性黏数增大,但DDP的摩尔分数为7%时其聚合难度增大;DDP的加入抑制了PET的结晶,Si O2的加入促进了PET的结晶;随着DDP含量的增加,PET的起始分解温度下降,含磷硅阻燃PET在800℃氮气氛围下质量保持率可达13.6%;随DDP含量的增加,含磷阻燃PET的极限氧指数（LOI）增大,当DDP摩尔分数为5%时,LOI达到了30.2%,加入质量分数为8%的Si O2后,含磷硅阻燃PET的LOI为31.5%,垂直阻燃性能达UL-94 V-0级;Si O2的加入能提高含磷硅阻燃PET的抗熔滴效果,使阻燃后的炭层石墨化程度提高。

A flame retardant,[（ 6-oxido-6H-dibenz[c,e][1,2]oxaphosphorin-6-yl） methyl]butanedioic acid（ DDP）,was introduced into polyethylene terephthalate（ PET） to produce a phosphorus-containing flame retardant PET by copolymerization,which was blended with silicon dioxide（ Si O2） to produce phosphorus-and-silicon-containing flame retardant PET with 2%- 8%Si O2 by mass fraction. The structure and properties of the phosphorus-and-silicon-containing flame retardant PET were studied.The results showed that DDP was introduced into PET macromolecular chain by polymerization,the intrinsic viscosity of the phosphorus-containing flame retardant PET was increased with the increase of DDP content,but the polymerization process became difficult as the mole ratio of DDP was 7%; the introduction of DDP inhibited the crystallization of PET when Si O2 promoted the crystallization of PET; the initial thermal decomposition temperature of PET dropped with the increase of DDP content,and the weight maintenance rate of the phosphorus-and-silicon-containing flame retardant PET reached 13. 6% at 800 ℃ in nitrogen; the limiting oxygen index（ LOI） of the phosphorus-containing flame retardant PET was increased with the increase of DDP content and reached 30. 2% at 5% DDP by mole fraction; the LOI of the phosphorus-and-silicon-containing flame retardant PET was up to31. 5% and the vertical flammability reached grade UL- 94 V-0 at 8% Si O2 by mass fraction; and the addition of Si O2 was beneficial to promoting the anti-melt dripping behavior of the phosphorus-and-silicon-containing flame retardant PET and raising the graphitization degree of the char layer.