Structure–property relationships of poly(vinyl alcohol). II. The influence of molecular regularity on the crystallization–dissolution temperature relationships of poly(vinyl alcohol)

Dissolution temperatures Ts have been determined for poly(vinyl alcohol) (PVA) samples of varying tacticity as a function of crystallization temperatures Tc. From the values of Ts and Tc, one can obtain values of (Tm)∞, the dissolution temperature of crystals of infinite stepheight. (Tm)∞ is a characteristic property of a given sample. This method of characterization is very sensitive and reliable for detecting differences in molecular regularity among PVA samples. The variation of (Tm)∞ with stereoregularity is attributed in part to differences in hydrogen‐bonding characteristics. Determinations of the crystallinities of solution‐crystallized PVA have shown that stereoregularity in PVA does not result in higher crystallizability.