Surface modification of poly (vinyl chloride) coated steel sheet by electron beam induced graft-polymerization

Surface modification of poly (vinyl chloride) (PVC) coated steel sheet by electron beam induced graft-polymerization with various monomers was investigated. As solubility parameters δ of monomers increased, mutual solubility of monomers and plasticized PVC decreased. As a result, apparent graft decreased with increasing δ of monomers. Degree of stain for grafted PVC coated steel sheet decreased with increasing δ of monomers. It is assumed that graft chains, which consisted of monomers with larger δ, prevented plasticizer from migrating in the interior side of PVC film. As grafting temperature increased, thickness of graft layer and average graft concentration increased, and degree of stain decreased. On the other hand, formability of grafted PVC coated steel sheet decreased with increasing grafting temperature. Layer grafted with methacrylic acid was rigid and made formability of PVC coated steel sheet decreased. In case of grafting with 2-hydroxyethyl methacrylate, graft layer was more flexible and hardly spoiled excellent formability of original PVC coated steel sheet. (author)