셀룰로스 나노크리스탈 복합화에 의한 Poly(vinyl alcohol-co-ethylene) 필름의 기체차단성 향상 효과

Barrier properties of packaging materials can be enhanced by controlling their microstructure and/or blending them with nanofillers such as cellulose nanocrystals (CNCs). CNCs have attracted considerable attention for use in reinforcing composite materials because of their exceptionally high specific strength and modulus, low density, chemical tunability, renewable nature, and relatively low cost. In this study, barrier films were prepared by incorporating CNCs into a poly(vinyl alcohol-co-ethylene) (EVOH) matrix. The CNCs prepared by acid hydrolysis of microcrystalline cellulose were ~348 nm long and 20 nm in diameter, with aspect ratios of 16. The nanocomposites were prepared by incorporating 1, 2, and 3 wt.% CNCs into an EVOH matrix using solution casting. Turbiscan analysis and contact angle measurements show that the EVOH/CNC composite films possessed interfacial interactions and good dispersion properties. As a result, these composite films may not show any decrease in their transparency. In particular, the oxygen transmission rate in the composite films significantly decreased from 3.2 cm3/(m2·day) to 1.3 cm3/ (m2·day) when the CNC was added, indicating that the EVOH/CNC nanocomposite films can be used as barrier packaging materials.