NGHIÊN CỨU THAY THẾ BỘT ĐÁ BẰNG THẠCH CAO PHẾ THẢI ĐỂ CHẾ TẠO VẬT LIỆU POLYME COMPOZIT CHỐNG CHÁY TRÊN NỀN POLYETYLEN TỈ TRỌNG CAO/COPOLYME ETYLEN VINYL AXETAT (HDPE/EVA)

Tóm tắt

In this study, waste gypsum (WGS) and CaCO3 powder were used as the fillers for the high density
polyethylene/copolymer ethylene vinyl acetate (HDPE/EVA) polymer blend. To improve the fire
resistance, the additives including zinc borate and decabromodiphenyl ethane were added to the
HDPE/EVA/WGS and HDPE/EVA/CaCO3 composites. Their processability, mechanical properties, fire
resistance and thermal stability were compared and discussed. The processing data showed that there
is no significant difference in the torque behaviors between HDPE/EVA/WGS and HDPE/EVA/CaCO3
composites. It proves that WGS can process easily as CaCO3 powder. By adding WGS, the flame
resistance of HDPE/EVA/WGS composites was fireproof grade V2 according UL94 standard. On the
contrary, CaCO3 particles did not effectively improve the fire resistance of the material. The tensile
characteristics and hardness (shore D) of HDPE/EVA/CaCO3 composites were higher than that of
HDPE/EVA/WGS compsites. Thermal gravimetric analysis (TGA) showed that onset degradation
temperature of HDPE/EVA/WGS (10%) composite was lower than that of HDPE/EVA/CaCO3 (10%)
composite; however, its maximum rate decomposition temperature (Tmax) was higher. Scanning
electron microscopy (SEM) images showed WGS and CaCO3 particles dispersed regularly in polymer
matrix that demonstrated the good adhesion of the both with the matrix. The obtained results
comfirmed that CaCO3 powder could be substituted by WGS to prepare the flame retardant composites.