Flame retardant high density polyethylene optimized by on-line ultrasound extrusion

摘要: Abstract The effect of on-line ultrasound application by a special static mixer die which promotes extensional flow simultaneously during the single screw extrusion process was thoroughly studied. proportion aluminum trihydroxide (ATH) used as flame retardant on high density polyethylene (HDPE) optimized. morphological, thermal, flammability, combustion, mechanical and rheological properties materials were investigated. morphological study pointed out that this is able to strongly reduce size ATH particles improve their dispersion distribution within polymer matrix. addition zinc borate (ZB) at low concentration (namely 3 phr) showed its well-known synergistic in oxygen index fire combustion behavior. According UL94 standard, rating for all tested changed from HB V2, with respect prepared without ultrasound; furthermore V0 achieved only 2 phr organo-clay. Rheological results under simple small amplitude oscillatory shear confirmed enhanced particle finer morphology evidenced larger values moduli deviations semicircular shape observed Cole–Cole diagram. Mechanical such Izod impact resistance, tensile strength, strain break tenacity also improved process. In work, appropriate conditions use lowest content (30 or 21.5 wt%) found, rendering HDPE optimized processability properties.