Effects of additives on the photo-induced grafting polymerization of N-isopropylacrylamide gel onto PET film and PP nonwoven fabric surface

In this study, the thermosensitive gels were grafted onto plasma-activated polyethylene terephthalate (PET) film and polypropylene (PP) nonwoven fabric surface. The Ar* plasma pretreatment was carried out and subsequent photo-induced surface graft polymerization was employed to graft the N-isopropylacrylamide (NIPAAm). The effects of additives during the grafting were accessed. The additives used were ammonium peroxodisulfate (APS, initiator), N, N, N′, N′-tetra-methylethylene-diamine (TEMED), promoter) and N,N′-methylenebisacrylamide (NMBA, cross-linking agent). The results indicate that the additives of APS, TEMED and NMBA will be beneficial in promoting the grafting. The additives, including all three, will give the best result. These grafted gels exhibit a lower critical solution temperature (LCST) at about 32 °C, which shows that the temperature-responsive behavior of bulk P (NIPAAm) hydrogel was preserved.