Crafted stock synthesis of ABS at the ultimate high ratio of polybutadieneto poly(styrene-co-acrylonitrile)

This study describes the emulsion grafting of styrene and acrylonitrile ont o 60-70% polybutadiene (PB), in the presence or absence of tert-dodecanetio l as a chain transfer reagent with a radical initiator, and the properties of the obtained grafted stock. There was no significant difference in terms of effect of the initiation mode on the grafting efficiency resulting from the high grafting reactivity of PB, However, the grafted stock with 70% PB prepared in the presence of tert-dodecanetiol and the adequate selection o f an initiation system gave a homogeneous dispersion of the PB particles in to poly(styrene-co-acrylonitrile) (SAN) matrix. The initiation system invol ves tert-butyl peroxylaurate, tert-butyl peroxyacetate, and tert-butyl pero xyisopropylcarbonate coupled with ferrous sulfate. The efficient coverage o f the SAN grafted layer around 70% PB particles was observed by TEM to even tually give excellent impact resistance, high surface gloss, and good therm al resistance. The absence of tert-dodecanetiol resulted in a toughness red uction of ABS. (C) 2001 John Wiley & Sons, Inc.