Preparation and evalution water resistance, mechanical and morpholgical characteristics of PVA/SiO2 nanocomposites for food industry applications

Abstract

Thin films prepared from Poly vinyl alcohol (PVA) and silica nanoparticles(SiO2 ) by using solvent casting method have been studied as potential packaging materials. PVA/ SiO2 nanocomposites were characterized by Fourier transform infrared (FT-IR), Scanning electron microscopy (SEM), Differential scanning calorimetry, atomic force microscopy (AFM), Water contact angle, Water absorption capacity ,Water solubility ,and mechanical properties. The results showed that the mechanical properties such as ( tensile strength, elongation at break ,modulus) increased with increasing nanoparticle content to7wt. % compared with pure PVA, while the mechanical properties decreasing with increasing SiO2 content to 9 wt. % , but it remains higher than the matrix material, also an increase in the crystallinity with addition 7wt. % from SiO2 which interpreted and supported the improvement of results of mechanical properties for nanocomposites PVA/SiO2, but Crystallinity decreased to 0.012 with increase SiO2 to 9 wt. %. The result of water contact angle showed the surface of nanocomposite films less hydrophilic. Result of FTIR showed that it does not create chemical bond between PVA and nanoparticles but only physical interaction. AFM measurements indicated a reduced the surface roughness with increase nanoparticles and was less roughness at percent 7wt. % SiO2 .However, the roughness is increased at 9 wt. % due to agglomerate the nanoparticles. The SEM results showed the good desperation between PVA and nanoparticles.