The Plasticizing Mechanism and Effect of Aluminium Chloride and Glycerin on Poly(vinyl alcohol) Films

Poly(Vinyl Alcohol) (PVA) films were prepared with AlCl3·6H2O/glycerin and AlCl3·6H2O/poly glycerin as two kinds of complex plasticizer. The micromorphology of pure PVA film and PVA films plasticized with complex plasticizer was observed by Scanning Electron Microscope (SEM). The interaction between complex plasticizer and PVA molecules was investigated by Fourier Transform Infrared (FT-IR) spectroscopy. The influence of complex plasticizer on crystalline, thermal and mechanical properties of PVA films was studied by X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC), ThermoGravimetric Analysis (TGA), and tensile tests, respectively. The results showed that both AlCl3·6H2O/glycerin and AlCl3·6H2O/poly glycerin complex plasticizers could interact with PVA molecular and then effectively destroy the crystals of PVA. PVA films plasticized with AlCl3·6H2O/glycerin, and AlCl3·6H2O/poly glycerin complex plasticizers became soft and ductile, with lower tensile strength and higher elongation at break compared with pure PVA films. This is an important cause of plasticization of AlCl3·6H2O /glycerin and AlCl3·6H2O /poly glycerin on PVA films.