Journal of Applied Polymer Science, Vol.79, No.8, 1384-1393, 2001
Cold plasma surface modification of conventionally and nonconventionally plasticized poly(vinyl chloride)-based flexible films: Global and specific migration of additives into isooctane
The effect of plasma-induced surface crosslinking of poly(vinyl chloride) (PVC)-based flexible films was investigated to limit its migration from packaging into fatty foodstuffs. The global migration was monitored by immersion into isooctane and the specific migrations of di-2-ethylhexyladipate (DEHA) and epoxidized soybean oil (ESO) were monitored by supercritical fluid chromatography analysis of the resulting isooctane solution. The plasma induced modifications were monitored with respect to the surface energy, weight loss, and surface crosslinking. The global migration from conventionally plasticized film, whose composition corresponds to an ordinarily used formulation for the manufacture of PVC wrap films, was controlled by different plasma treatments and the best results were obtained with Ar plasma. Further decreases in global migration were obtained by treating permanently plasticized films containing an elastomeric ethylene-based terpolymer (EE in complete or partial replacement of DEHA. Before treatment, the replacement of DEHA with EE increased the DEHA and ESO specific migrations. Argon plasma treatment of permanently plasticized films led to samples that did not exhibit any migration.