Self‐association through hydrogen bonding and sequence distribution in poly(vinyl acetate‐co‐vinyl alcohol) copolymers

Abstract

Correlation between hydrogen-bonding self-association and sequence distribution in poly(vinyl acetate-co-vinyl alcohol) copolymers (ACA) with different degrees of basic hydrolysis and sequence distributions has been studied by thermal analysis and NMR spectroscopy. 13C NMR spectroscopy has also been used to elucidate the blocky nature, branching, and tacticity of the copolymers. Thermal analytical studies indicate that hydrogen bonding distribution in block alcohol and vinyl acetate copolymers strongly depend on the sequence distribution wherein hydroxyl-hydroxyl self-association is preferred.

Melting behavior and surface morphology of poly(vinyl acetate‐co‐vinyl alcohol) copolymer

“…In our earlier work, the constant crystallization temperatures of polymer samples were determined by DSC. Subsequently, DSC results were analyzed by Flory's and Baur's theories and then compared with the NMR data 3…”

“…After each heating, the weight of the pan was recorded, which is given in the Table I. The equilibrium melting temperature was obtained in our earlier work 3. Differential scanning calorimeter (DSC) data were obtained using a Perkin–Elmer DSC‐7 equipped with a thermal analysis data station.…”

“…The equilibrium melting temperature was obtained in our earlier work. 3 Differential scanning calorimeter (DSC) data were obtained using a Perkin-Elmer DSC-7 equipped with a thermal analysis data station. A polymer sample was run in aluminum pans with a sample weight of 8 -12 mg under a nitrogen atmosphere.…”

“…The former is usually made from a block copolymer in which corona‐forming blocks are longer than are the core‐forming blocks, while the latter is made from a copolymer in which the core‐forming blocks are much longer 1. The thermal analytical technique has been widely used to characterize the comonomer sequence distribution in the poly(vinyl acetate– co –vinyl alcohol) (ACA) copolymer 2, 3. The micelle formation in ACA copolymers was observed by thermogravimetric and X‐ray analyses 3…”

“…1 The thermal analytical technique has been widely used to characterize the comonomer sequence distribution in the poly(vinyl acetate-co-vinyl alcohol) (ACA) copolymer. 2,3 The micelle formation in ACA copolymers was observed by thermogravimetric and X-ray analyses. 3 Amphiphilic copolymers are an important material in the fields of natural science and biochemistry as well as in the industrial field.…”