Cerium–initiated Polymerisation of Some Vinyl Compounds in Polyamide Fibres

Abstract

Several vinyl polymers have been grafted onto nylon 6. 6 with ceric salts as initiators. Some factors influencing the polymerisation of acrylic acid have been examined in detail, and evidence obtained that the products are true graft copolymers. Grafting of both 2–vinylpyridine and 4–vinylpyridine is slow from solutions in dilute sulphuric acid or nitric acid, but rapid from perchloric acid. Slow diffusion of initiator into polyamide fibres is apparently responsible for a non–uniform distribution of polymer sometimes observed. Nylon 6. 6 is oxidised slowly, but extensively, by cerie salts and the reaction is accelerated by oxygen. Analyses of the products are consistent with oxidation at methylene groups adjacent to the amide nitrogen rather than at amine end–groups. A paradox, thatdinitrophenylation renders nylon less susceptible to grafting of poly(acrylic acid), but not to oxidation by eerie salts, is tentatively explained. The surface electrical resistivity of nylon fabric is not lowered by grafted polyacrylamide or its N–alkyl derivatives, whilst salts of poly(acrylic acid) and poly(vinylpyridines) impart only a temporary lowering. Poly(1–rnethyl–4–vinylpyridinium) perchlorate was more permanently effective. Attempts to polymerise some potentially antistatic betaine–type monomers in nylon were unsuccessful.

Ceric-Ion-Initiating Surface Graft Polymerization with Regional Control and Dimensional Precision

“…In general, ceric-ion-initiated radical polymerization is affected by several reaction variables such as ceric ion concentration, , monomer concentration, and pH of the medium . The ceric ion concentration dependence of surface composition upon graft polymerization of acrylamide on the PVA-fixed PET surface is shown in Figure .…”

“…The oxidative initiation of radical polymerization by Ce IV ions on hydroxylated polymers such as PVA and cellulose has been extensively investigated over the years. − In particular, in their recent article, Storey and Goff summarized the complexity of mechanisms as follows. According to the well-accepted mechanism for ceric-ion-inducing graft polymerization on PVA, there are two pathways involved in the formation of a free radical.…”