Optimization of conditions for grafting acrylic acid to polyethylene terephthalate by radiation

The swelling behaviour of polyethylene terephthalate (PET) film in different media has been examined; the γ-ray induced graft copolymerization to PET of acrylic acid in these media has also been investigated. The influence of film thickness and crystallinity as well as the nature of the swelling agent are discussed with reference to the resultant degrees of equilibrium swelling and grafting. Aqueous dichloracetic acid is a suitable swelling agent for grafting to crystalline PET; methanol is adequate, but less efficient, for grafting to amorphous PET. Swelling and grafting in the case of PET fabric are complicated by dissolution and physical disintegration, respectively. However, grafting to a fairly low extent can be accomplished in dilute aqueous dichloracetic acid.