GRAFT COPOLYMERIZATION OF ACRYLONITRILE ON ALLYLATED PINEAPPLE (ANANASCOMOSUS) FIBRE USING REDOX PAIR OF POTASSIUM PERMANGANATE AND N-BUTYLACETATE

Abstract

The graft copolymerization of acrylonitrile onto allylated pineapple (Ananascomosus) fibre by potassium permanganate, n-butylacetate as redox pair in aqueous media was investigated. Potassium permanganate, n-butylacetate redox pair was effective for the initiation of graft copolymerization of acrylonitrile onto cellulose and its ally derivative.The effect of permanganate on grafting of acrylonitrile onto modified and unmodified fibre was also examined. The graft yield was significantly higher for the unmodified fibre giving values of up to 290% compared to 130% for the allyl derivative at 12.5 x 10^-3M of KMnO₄. Resonance stabilization of the allyl radical and consequent reduction in its reactivity for graft reaction accounted for the difference in grant yield. At permanganate concentration greater than 12.5 x 10^-3M, the graft yield for the unmodified fibre decreased with increase in KMnO₄. This was associated with the termination of the graft reaction by manganite ion.The IR spectra of the unmodified, allylated and grafted pineapple (Ananascomosus) fibre were recorded. The absorption band of value 3419.83 cm^-1 confirmed the presence of unbounded hydroxyl groups of anhydrous unit of the unmodified fibre. The absorption band of -C=C-, -C-O-C- and -C-H bending at values of 1642.58 cm^-1, 1157 cm^-1 and 898.01 cm^-1 respectively which confirmed the presence of allylic moiety in the allylated pineapple (Ananascomosus) fibre. The absorption bands of -C=C-, -C-O-C-, =C-H, and C=N at values of 1634.28 cm^-1, 1160.74 cm^-1, 896.79 cm^-1 and 2346.40 cm^-1 respectively confirmed the grafting of acrylonitrile onto pineapple (Ananascomosus) fibre.