An effective charring agent,poly(para-phenylene terephthanlamide)(PPTA),for halogenfree flame retardant polypropylene was synthesized through solution polycondensation,and the effects of PPTA on flame retardance of glass fiber-reinforced polypropylene(GF-PP)/IFR system were studied.Thermogravimetric analysis(TGA)data implied that loading of PPTA could improve the thermal stability of GFPP/IFR system.PPTA could considerably enhance the fire retardant performance as evidenced by the increase of limiting oxygen index(LOI)values,the results of UL-94tests.Scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR)and Laser Raman spectroscopy(LRS)of the composites revealed that PPTA could promote the formation of compact intumescent charred layers in GF-PP/IFR system after burning.The problem ofcandlewick effectrelates to the glass fiber is successfully solved by introduction of the charring agent PPTA.

A charring agent(CA)was prepared by modifying pentaerythritol(PER),then it was mixed with the intumescent flame retardant(IFR)for glass fiber-polypropylene(GF-PP).The flame resistance and flame-retardant mechanism were studied by Fourier transform infrared spectrometer(FT-IR),thermogravimetry(TG),cone calorimetry analysis,scanning electron microscope(SEM)and Raman spectroscopy.The resultsindicate that with an addition of 1%CA toGF-PP/IFRsystem,UL-94 of GF-PP/IFRsystem can achieve V-0,the limiting oxygen index(LOI)can reach 27.9.The flame-retardant mechanism of CA is that CA can increase the graphitization content and compactness of GF-PP/IFR system proved by FT-IR,Raman spectra and SEM photos.

The invention discloses a formula of PC/ABS alloy modified by PC defective material, which comprises the following parts:45-60% PC recycling material, 20-35% ABS, 1-5 % grafted copolymer, 1-5% flexibilizer, 3-10% epoxy resin, 0.1-0.5% anti-oxidant, 6-12% bromoflameproof agent, 1-2% antimony flameproof agent, 1-2% inorganic flameproof agent, 0.1-1% smoke suppressor, 0.1-1% lubricate and 0.2-0.8% politef. The alloy can do blended modification for PC recycling material and ABS, which reduces viscosity of PC fuse without extra burden for environment.