Radiation grafting of acrylic acid, methacrylic acid and polyfunctional methacrylates onto poly(vinyl chloride)

Gamma and electron-beam radiation induced graftcopolymerization of acrylic acid, methacrylic acid, trimethylolpropane trimethacrylate (TMPTMA) and tetraethyleneglycol dimethacrylate (TEGDMA) onto PVC-films has been investigated. Both swelling effect and oxygen retardation effect in air radiation phase were found to be nonsignificant below the dosages of 1.2 Mrad due to the protection of free radicals by the quick formed gel's network. The graft percentage was increased with the dose-rate and the total dosage, becoming slowly levelling over the doses of 2.4 Mrad. The grafting-rate is regarded to be proportional to the n-th power of the dose- rate, where the value of n being as 1.10

1.38 for gamma-irradiation and 1.27

1.42 for electron- beam irradiation. Electron-beam irradiation, being extremely high dose-rate, stimulates the grafting-rate, especially the grafting-rate of polyfunctional TEGDMA and TMPTMA because of the quick formation of three dimensional network formed by intra- and inter-crosslinking. Although the grafting results of both gamma and electron-beam irradiation are similar, the latter irradiation favors the mass graft-processing of PVC-films.

The formation of the grafted stratum on the PVC-film surfaces was found to induce the positive effects of big improvement in tensile-strength, excellent resistant toughness against the erasure of the prints on the grafted PVC-film surfaces and strong adhesive character with several adhesive chemicals.