Study On Flame Retardancy Of ABS Resin Using Silicone With Methyl And Phenyl

Acrylonitrile-Butadiene-Styrene (ABS) resin is one of the most extensive engineering plastics, which has excellent performances. Nevertheless the limiting oxygen index (LOI) of ABS resin is only about 18%, it is very esay burning in the air. Halogen-containing flame retardants were the most important flame retardent system, which have lower adding quantity, good flame retardant effect, mezzo price and good mechanics performances for flame retardant ABS resin. But when it was burning, it could give birth to plenty of black smoke, poisonous halogen hydride gas and carcinogen. Halogen-containing flame retardants for ABS resin were badly striked when WEEE injunction (Waste Electrical and Electronic Equipment) and RoHS injunction (The Restriction of Hazardous Substances in Electrical and Electronic Equipment) were enacted in European Union. So more and more researchers were studying innocuous or lower poisonous halogen-noncontaining flame retardant systems for ABS resin, which have high flame retardant effect and lower producing smoke.Silicon-containing flame retardants have low burning rate, low thermal liberating rate, preventing dropping and excellent flame retardancy. They can give good process ability and mechanics performances for substrate material. Especially, they are recognized by people because of producing low smoke and low carbon monoxide, and environment amity. Organic silicone (also called polysiloxane) were rapidly developing among silicon-containing flame retardants.In this article, flame retardant of silicone with methyl and phenyl was successfully synthesized through hydrolysis condensation reaction by using alkoxysilane as raw materials and acid as catalyst. The influence of the thermal stability and molecular weight of silicone resin were discussed by changing the factors of reaction time, water volume, mode of dropping, etc and reaction method. The fitting reaction conditions: reaction time was 2 hours, reaction temperature was 80℃, water volume was from 5 times to 10 times, alkoxysilane was mode of positive dropping, acetic acid was catalyst and end capping time is 45 minutes. The thermal weight loss rate of the best thermal stability silicone with methyl and phenyl was only 26.03% at 1000℃in protecting gas, which the molecular weight was 16418. The key of flame retardance for silicone with methyl and phenyl was excellent thermal stability and promoting char yield of system.For the first time, silicone with methyl and phenyl, potassium 4-(phenylsulphonyl) benzenesulphonate and silicone with methyl and phenyl admixture were respectively melt blending with ABS resin. The flame retardant effect, physics and mechanics performances of ABS blending system were studied. With adding the flame retardancy of silicone with methyl and phenyl, LOI, thermal stability, heat distortion temperature and Vicat softening point temperature of ABS resin was enhanced, but mechanics properties of ABS resin was falling, the impact strength was the most evident falling among mechanical properties, melting index was also falling which can't influence any process ability. Compared adding silicone with methyl and phenyl and 0.5wt% potassium 4-(phenylsulphonyl) benzenesulphonate admixture with adding equal silicone with methyl and phenyl, the LOI of ABS resin was increasing 1 percent, thermal stability was increasing, heat distortion temperature and Vicat softening point temperature of ABS resin were hardly change, melting index was appreciably increasing, mechanics properties was appreciably falling.When adding 20wt% silicone with methyl and phenyl and 0.5wt% potassium 4-(phenylsulphonyl) benzenesulphonate admixture through melting blending with ABS resin, thermal stability of ABS blending system was obviously enhanced, the LOI was 22.8%. Comparing with pure ABS resin, the LOI enhanced 30.3%, the heat distortion temperature enhanced 2.5℃, the Vicat softening point temperature enhanced 4.8℃, but the impact strength was falling 53.4%, the tensile strength was falling 32.1%, the fracture elongation was falling 43.1%, the bend strength was falling 34.7%, the deflection was falling 40.6%.