Cerium–initiated Polymerisation of some Vinyl Compounds in Cellulose Fibres

Abstract

The effects of monomer and initiator concentration on the graft polymerisation of acrylic acid and of 2–vinylpyridine in viscose rayon and cotton, initiated by ceric ammonium sulphate in dilute sulphuric acid, have been examined. Polymerisation of acrylic acid occurs less readily in cotton treated with caustic soda, and in acid–modified cotton, than in the parent fibre. Neither preliminary treatment with initiator nor partial oxidation with sodium periodate affects the extent of subsequent grafting of poly(acrylic acid) to viscose rayon under selected conditions. The rate of polymerisation of 2–vinylpyridine in cellulose is lower than that of acrylic acid, but polymerisation is greatly accelerated by substituting dilute perchloric acid for sulphuric acid as the solvent. This is apparently a manifestation of the ‘gel effect’ and has been observed with other basic monomers that form insoluble polymer perchlorates. Proof is offered that both acrylic acid and 2–vinylpyridine afford true graft copolymers with cellulose. These polymers do not improve the mechanical properties of viscose rayon filaments. Support for the view that oxidative C (2) –C (3) bond–fission participates in the initiation of polymerisation in cellulose by eerie salts is provided indirectly by the isolation of adipaldehyde as a major product from the oxidation of cyclohexane– trans –l, 2–diol with ceric ammonium nitrate.