PLASMA-INDUCED HYDROGEL GRAFTING OF VINYL MONOMERS ON POLYPROPYLENE

Polypropylene (PP) film was plasma-treated using a 13.56 MHz direct pl asma with argon, nitrogen, and oxygen as the plasma-forming gases. The three gases induced very different changes on the PP film surface, wh ich were studied using contact angle measurements. Because of its degr ading and oxidative effect, oxygen plasma pretreatment was not used fo r the homogeneous grafting of acrylic acid and acrylamide. Nitrogen pl asma treatment did not lead to the formation of stable peroxides on th e film surface and did not undergo grafting reactions. This may be due to the types of radicals and functional groups created on the surface during the plasma treatment. Finally, argon plasma pretreatment was f ound to be the most effective for the grafting of vinyl monomers. The amount of grafted poly(acrylic acid) was shown to be proportional to t he concentration of peroxides created by argon plasma treatment.