Structure, Mechanical, and Swelling Behaviors of Poly(vinyl alcohol)/SiO2 Hybrid Membranes

Abstract

Poly(vinyl alcohol) (PVA) has a wide application in industry and the biomedicine area, but its poor water resistance and insufficient mechanical strength have severely limited its application. To overcome these limitations, in this study, inorganic silica sol was used to modify organic PVA. The tensile results show that the tensile strength and Young’s modulus of these hybrid films were greatly improved compared to the neat PVA film. For the sample containing 20 wt% silica, compared to PVA matrix, considerable increases in tensile strength and Young’s modulus by factors of 1.9 and 3.2, respectively, were achieved. The solubility measurements showed that the hybrid has an enhanced water resistance, in other words, the solubility and degree of swelling decreased with the addition of silica. FTIR, DSC, XRD, and ESEM were used to investigate the chemical and crystal structure of the hybrids, morphology, and composition of the particles in the matrix, respectively. Strong interfacial bonding between the silica and the PVA matrix and homogenous distribution of the silica particles in PVA are supportive of markedly improved mechanical strength. These modified properties of PVA with the addition of silica broaden the applications of PVA, especially giving insight in to the applications of PVA in medical materials.