Radiation grafting of poly(ethylene terephthalate) (PET) fibre,II. Hydrolysis of grafted poly(vinyl acetate) to poly(vinyl alcohol)

Poly(ethylene terephthalate) fibres grafted with poly(vinyl acetate) by γ-radiation were hydrolysed under alkaline and acidic conditions in order to obtain poly(ethylene terephthalate)-graft-poly(vinyl alcohol) fibres. In alkaline media poly(ethylene terephthalate) degraded without appreciable conversion of acetate to hydroxyl groups. During acid hydrolysis no change in tensile properties of the fibres was observed up to an extent of 50% conversion of acetate to hydroxyl groups. Further change in the tensile strength and the elongation at break was attributed partly to the grafted poly(vinyl acetate)/poly(vinyl alcohol) balance and partly to the loss due to degradation of the fibres.