Preparation and characterization of poly(ethylene terephthalate) powder-filled high-density polyethylene in the presence of silane coupling agents

Micron-size crystalline particles of Poly(ethylene terephthalate) (PET), ob tained from PET bottles by crystallization and grinding, were used as a fil ler in high-density polyethylene (HDPE). The composite of PET particle-fill ed HDPE was prepared by melt mixing at 190 degreesC, which was well below t he melting temperature of PET. Silane coupling agents (SCAs) were used to e nhance the interaction between PET and HDPE in the composite. A chain exten der (CE) and maleic anhydride (MA) were also used to provide further intera ction with SCAs between these two materials. The ultimate tensile strength, especially at highest content 40% PET-filled HDPE, and the impact strength of SCAs-treated PET-filled HDPE was found to be highly improved compared t o untreated PET filling into HDPE. Dynamic mechanical analyses (DMA) demons trated that T-g of the main matrix polyethylene was depressed from 3 to 10 degreesC. Scanning electron microscopy (SEM) studies indicated a strong int eraction between PET powder and HDPE when SCAs were present in the system. (C) 2000 John Wiley & Sons, Inc.