Melt Processing of Polyvinyl alcohol) Through Adding Magnesium Chloride Hexahydrate and Ethylene Glycol as a Complex Plasticizer

摘要

The melt processing of polyvinyl alcohol) (PVA) was achieved using magnesium chloride hexahydrate (MgCI2·6H2O) and ethylene glycol as a complex plasticizer. The interaction between the complex plasticizer and PVA was studied by Fourier transform infrared spectroscopy (FT-IR). The PVA films were characterized using X-ray diffraction (XRD), differential scanning cal-orimetry, thermogravimetric analysis (TGA), scanning electron microscope, and dynamic thermomechanical analysis (DMA) techniques. The band shift of the observed peak around 3335 cm~(-1) in the FT-IR spectra indicates that the complex plasticizer MgCI2·6H2O and ethylene glycol could form strong interactions with PVA and thus interrupt the intermolecuiar and intramolecular hydrogen bonding in PVA. The XRD results show that the addition of the complex plasticizer would significantly destroy the crystallites of PVA and result to the decrease of the degree of crystallinity of PVA. The melting point was reduced from 229 C of pure PVA to around 170 C after the plasticization. The TGA studies show that with the complex plasticizer, the thermal stability of PVA is improved. PVA plasti-cized by 30 wt% MgCI2·6H2O and 10 wt% ethylene glycol shows the tensile strength of 33 MPa and the elongation at break of 362%.