Preparation of high molecular weight polyvinyl alcohol by emulsifier-free emulsion polymerization

In this report, high molecular weight polyvinyl alcohol (PVA) was prepared by emulsifier-free emulsion polymerization, using the redox initiator of potassium persulfate (KPS) / N,N-dimethyl ethanolamine (DMEA). The structure and property of PVA were studied by using ubbelohde viscometer, fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance hydrogen spectroscopy (1H-NMR), X-ray Diffraction (XRD), differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA). The results showed that the viscosity-average degree of polymerization (DP) of PVA 7506, which was much higher than that of PVA commonly used in industrial production. The syndiotacticity and crystallinity of PVA was 54.2 % and 35.6 %, respectively

Preparation and study of Polyvinyl Alcohol/Attapulgite nanocomposite fibers with high strength and high Young’s modulus by gel spinning

Polyvinyl alcohol (PVA)/Attapulgite (ATT) nanocomposite fibers with high strength and high Young’s modulus were prepared via gel spinning. The structures and properties of PVA/ATT nanocomposite fibers were investigated with Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimeter (DSC), thermo gravimetric analysis (TGA), x-ray diffraction (XRD), Environmental scanning electron microscope (ESEM), and mechanical testing. The results showed that ATT had a great influence on the structures and properties of PVA/ATT nanocomposite fibers. The melting temperatures, crystallinities, initial decomposition temperatures and maximum decomposition temperatures of PVA/ATT nanocomposite fibers increased firstly when ATT content was increased from zero to 3 wt%, however, they were then dropped when ATT contents were 5 wt% and 7 wt%. The highest melting temperature, crystallinity, initial decomposition temperature and maximum decomposition temperature of PVA/ATT-3 were 240.4 °C, 67.6%, 266.7 °C and 358.6 °C, respectively. Furthermore, ESEM observation indicated that ATT had good adhesion to PVA matrix. Mechanical tests showed that PVA/ATT-3 had the highest breaking tensile and Young’s modulus of 12.6 cN/dtex and 301.9 cN/dtex, respectively