On the production of compatibilized polyethylene terephthalate - Styrene butadiene rubber blends

Styrene-butadiene rubber (SBR) is chemically modified with maleic anhydride (MAH) in a continuous process (reactive extrusion) at three different extr usion speeds with and without reaction initiator (benzoyl peroxide). the re sulting modified rubber is used to produce compatibilized blends with polye thylene terephthalate (PET). The amount of grafted MAH groups on the rubber is determined by chemical titration and the degree of grafting is measured by infrared analysis. The degree of compatibilization between SBR and PET is determined indirectly through measurements of mechanical properties and average molecular weight of the blends. The anhydride and peroxide concentr ation influences the grafting reaction strongly and hence the mechanical pr operties and impact resistance of the blends. Compatibilization of the elas tomeric and plastic phases at specific processing conditions gives rise to large improvements in the impact resistance of the blend over that of PET a lone. (C) 2000 John Wiley & Sons, Inc.