Abstrato

Preparation of tripolyphosphatemodified graphite intercalation compound and its influence on polyethylene combustion characteristics

Xiuyan Pang,Weishu Chang, Zhixiao Zhai, Ruinian Lin

A tripolyphosphate modified expandable graphite (written as EGP) was prepared through flake graphite intercalation reaction with H2SO4 as main intercalator and sodium tripolyphosphate as assistant intercalator simultaneously. The dilatability, main intercalated function group, crystal structure of the products were detected, and its influence on combustion characteristics of linear low density polyethylene (LLDPE) were investigated. Results show that EGP exhibits higher dilatability and flame retardancy for LLDPE than the referenced single H2SO4 intercalation compound (written as EG). Addition of EGP can obviously improve LLDPE flame retardance. The limiting oxygen index (LOI) of 70LLDPE/30EGP can reach 28.4%, which is obviously higher than that of pure matrix of 17.5%. Whereas, the same dose of the referenced EG only improve the LOI of 70LLDPE/30EG to 25.1%. Furthermore, the combination of EGp and ammonium polyphosphate (II) (APP) makes the 70LLDPE/10APP/20EGP system present a LOI of 31.9%, and its UL 94 level reaches V-0.