Non-equimolar alpha-methylstyrene/maleic anhydride copolymer(s) prodn. - by radical-initiated soln. copolymerisation in presence of organo-bromine cpds., esp. tetra-bromo-methane, or excess alpha-methylstyrene

摘要

A process (a) for the prodn. of non-equimolar alpha-methylstyrene / maleic anhydride (AMS/MA) copolymers (I) comprises soln. polymerisation at 40-100 deg.C in the presence of radical initiators (II) and 0.01-6.0 wt.% CH2Br2, CHBr3, CBr4, CBr3Cl or CBr2Cl2 (III). Alternatively, the reaction can be carried out (b) in the presence of a Br cpd. (III) which has been pre-reacted with a vinylaromatic or alpha-olefin in the presence of a radical initiator (IIA), or (c) in the presence of 0.01-3.0 wt.% of a combination of (III) and FeCl3 in the wt. ratio (100:1)-(1:1), or (d) in excess AMS in the presence of 0.5-5.0 wt.% initiator (II). USE/ADVANTAGE - The process enables the prodn. of statistical, (non-alternating) AMS/MA copolymers with mol. wt. 400-20,000. (I) have Tg 150-200 deg.C and m.pt. 190-250 deg.C without decompsn.; they are therefore suitable for reactive compounding with OH and amino gp.-contg. polymers such as polyesters and polyamides (contrast prior-art alternating AMS/MA copolymers).