Plasma Homo- and Copolymerization of Allyl Alcohol and Styrene

A pulsed plasma was used to initiate homo- and copolymerization of allyl alcohol and styrene. The pure monomers and a mixture of both components in a molar ratio 1:1 were polymerized at different duty cycles. The concentration of hydroxyl groups of the resulting plasma polymer layers was determined by derivatization with trifluoroacetic anhydride (TFAA) and XPS. In this way the number of OH groups at the surface of the (co)polymer layers could be adjusted from 0 (styrene homopolymerization) to 31 OH groups/100 C atoms (allyl alcohol homopolymerization). It was found that the copolymerization corresponds to a pure chemical (radical) copolymerization. Thus, the variation of OH group density is possible only in a small range of comonomers mixing ratio, otherwise, styrene homopolymerization dominates.