Abstract

This research aims to modify ultrafne fully vulcanized powdered natural rubber (UFPNR) prepared by emulsion
graft-copolymerization with styrene (St) and acrylonitrile (AN) monomers onto deproteinized natural rubber (DPNR).
The efects of monomers content and St/AN weight ratio on grafting efciency and thermal stability of the devel�oped DPNR-g-(PS-co-PAN) were investigated. The results showed that grafting efciency was enhanced up to 86% with monomers content 15 phr and weight ratio St:AN 80:20. The obtained DPNR-g-(PS-co-PAN) was radiated by an electron beam at various doses, followed by a spray drying process to produce UFPNR. The obtained modifed UFPNR particles irradiated at dose up to 300 kGy were relatively spherical with a particle size of approximately 4.4 µm. Fur�thermore, the degradation temperature of 5wt% loss (Td5) of UFPNR was found in the range of 349–356 °C. The results revealed that the modifed UFPNR is suitable as a toughening fller for a broader spectrum of polymers.