Novel antifog modification for controlled migration and prolonged wetting of LLDPE thin films

Abstract

This paper focuses on the development of a novel modification method of commonly used antifog (AF) additives such as glycerol monooleate (GMO) and sorbitan monooleate (SMO). In this method, the AF organic molecules were grafted to vinyl silane, methacryl-oxypropyl-trimethoxy-silane (MEMO), to form MEMO grafted GMO (MEMO-g-GMO) and MEMO grafted SMO (MEMO-g-SMO). A thorough study of linear low density polyethylene (LLDPE) containing the modified AF (LLDPE/MEMO-g-AF) was performed, including investigation of the additives' migration from the LLDPE matrix.Thermal gravimetric analysis (TGA) and Fourier transform IR (FTIR) measurements showed a successful grafting of GMO and SMO to MEMO. Thermal analysis showed that 1 part per hundred parts resin (phr) MEMO-g-GMO has no effect on the thermal decomposition of LLDPE. According to hot fog test results, it was found that only LLDPE films containing 1phr MEMO-g-GMO exhibited excellent antifog performance, while LLDPE films containing 1phr MEMO-g-SMO exhibited poor antifog performance. It was found that LLDPE/MEMO-g-GMO system is characterized by a slower AF migration rate and a lower diffusion coefficient, compared to the reference system, LLDPE/GMO; these results are well correlated with the hot fog test results. Morphological studies revealed a fine dispersion of the MEMO-g-GMO in the polymer.