Dennis Bruce Patterson

Synthesis of copolymers of m-diisopropenylbenzene and m-dimethoxybenzene

The polymerization of diisopropenylbenzenes (DIPB’s) was first reported over 25 years ago. As opposed to free radical initiated polymerizations, which produce cross-linked gels ionic initiated polymerizations produce soluble (uncrosslinked) polymer. Anioic techniques, for examples, can produce linear polymer in which only on unsaturation of each DIPB is consumed. The aromatic ring of each pendant group thus carries an unreacted isopropenyl group.1

The Microstructure of Cyclized Polyisoprene

The modification of polyisoprene by treatment with strong acid dates, in the case of natural rubber, to at least the late 18th century.1 It has been accepted for some time now that the resinification and loss of unsaturation accompanying such treatment are due, in most instances, to acid-catalyzed cyclization. The earlier work on such cyclization has been reviewed thoroughly1–6 and only a brief overview of the main aspects will be given here.