UV 방사선 그라프팅 중합을 이용한 고밀도 폴리에틸렌 시트의 표면 개질

Abstract

1,6-Hexanediol diacrylate(HDDA) was grafted onto high density polyethylene(HDPE) substrates in the presence of benzophenone(BP) and isopropylthioxanthone(ITX) photoinitiators, and then polyurethane acrylate formulation were coated onto the HDDA-g-HDPE substrates using UV radiation. Grafted amount and grafting efficiency of the polymerzations were determined by gravimetric method. The effects of the photoinitiator concentration and the UV radiation intensity on the physicochemical surface properties and the grafting efficiency of the UV radiation grafting polymerizations were investigated in detail using contact angle measurements, fourier-transform infrared spectroscopy with attenuated total internal reflection (FTIR-ATR), and scanning electron microscopy (SEM) as characterization. The results showed that the grafted amount and the surface polarity of the HDDA-g-HDPE substrates were increased linearly with increasing the BP photoinitiator concentration and the UV radiation intensity; the addition of a small amount of ITX markedly enhanced both the grafted amount and the surface polarity of the HDDA-g-HDPE substrates probably due to the photosensitization effect. The adhesion of the UV-cured coating onto the HDDA-g-HDPE substrates was evaluated by using the crosshatch adhesion test. The results indicated that the grafted amount of HDDA onto the HDPE substrates requires above about 1 × 10-2 mmol/cm2 to be shown the satisfactory adhesion with the UV-cured coating.