Radical copolymerisation of maleic anhydride with trans‐stilbene

Radical copolymerisations of maleic anhydride and trarcs-stilbene have been carried out in methyl ethyl ketone at 60°C using 2,2′-azo-bis-isobutyronitrile as initiator. The copolymers formed at all feeds are slightly rich in maleic anhydride units but are heterogeneous with regard to both composition and molecular weight distribution. It is concluded that this effect is probably produced by phase separation during the copolymerisation and that any interpretation of copolymerisation rates or copolymer compositions in terms of mechanism is not straightforward.