Synthesis And Characterization Of Poly(Vinyl Propional) With High Acetalization RateAuthor(s): Neelotpal Sen Sarma, Prafulla Chetri, Narendra Nath Dass
In this paper an attempt has been made to dissolve poly(vinyl alcohol) (PVA) in non-aqueous medium in the presence of catalytic concentration of C2H5ONO2⋅DMSO (EN⋅DMSO). Poly (vinyl propional) (PVPL) was prepared by acid catalysed homogeneous acetalization of PVA of molecular weight 14,000 with propanaldehyde. The formation of the acetal was confirmed by IR and 1H-NMR spectroscopy. The PVPL prepared had a degree of acetalization of 92 mol%. The molecular mass of the acetal was determined by gel permeation chromatograpy (GPC). The glass transition temperature,Tg and other kinetic parameters were measured from differential scanning calorimetric (DSC) thermograms. Thermal stabilities were checked by thermogravimetric analysis (TGA) and differential thermagravimetric (DTG) method. The acetal decomposed in three stages. The corresponding initial decomposition temperatures were found to be 280, 410 and above 500oC.