Melting point and heat of fusion of poly(vinyl alcohol)

Abstract

Differential thermal analysis was used to study the effect of a diluent, glycerol, and copolymer units, acetate groups, on the melting point of poly(vinyl alcohol) (PVA). The melting point of PVA was found to be 228°C. and the heat of fusion by the diluent and copolymer methods was 1.64 and 0.56 kcal./mole, respectively, based on vinyl alcohol units. Flory's theory was used as a basis for analysis. The results are compared with literature values for the heat and entropy of fusion of polyethylene, and the differences briefly discussed.

New crosslinked cast films based on poly(vinyl alcohol): Preparation and physico-chemical properties

“…The glass transition temperature (T g ) was taken at the onset of the heat capacity jump and the melting point (T m ) at the maximum of the endothermic peak. The crystallinity degree (X c ) was calculated using the value of 162 J/g which is the most cited reference melting enthalpy for PVOH crystals [18][19][20]. Three replicates were analyzed for each film.…”

Preparation and thermal properties of thermoplastic poly(vinyl alcohol) complexes with boronic acids

“…The endothermic peak due to the melting of PVA appeared at about 226°C. 17 It can be seen that the melting temperature (T m ) of the PVA complexes decreases with increasing the boronic acid concentration. It is to be noted that the melting temperature of PVA decreases by introducing a small amount of boronic acids; in the case of PVA-PBA complexes, the introduction of boronic acids of 10 mol % lowers the melting temperature of PVA from 226 to 192°C.…”

Miscibility and interactions in poly(n-propyl methacrylate)/poly(vinyl alcohol) blends

“…where DH f is the apparent enthalpy of the fusion of PVA in the blend, W is the weight fraction of PVA, and DH 0 f is the enthalpy of fusion of completely crystalline PVA (156 J/g for PVA [20]). For polymer blends containing a crystalline component, the variation in values of T m and c c is usually attributed to interactions between the components [21][22][23].…”