The reaction of acid chlorides with poly(viny1 alcohol) (PVA) leads to vinyl alcohol-vinyl ester copolymers. The esterification by Schotten-Baumann enables degrees of modification to be reached which depend on the chemical structure of the pendant unit introduced. High degrees of modification were o
Crosslinking of poly(vinyl alcohol) using dianhydrides as hardeners
✍ Scribed by V. Giménez; A. Mantecón; V. Cádiz
- Publisher
- John Wiley and Sons
- Year
- 1996
- Tongue
- English
- Weight
- 532 KB
- Volume
- 59
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
The crosslinking reaction of poly(viny1 alcohol) (PVA) with 3,3',4,4'-tetracarboxybenzophenone dianhydride, pyromellitic carboxylic acid anhydride, and Epiclon B-4400 as hardeners was studied either in solution or by differential scanning calorimetry. A catalyst agent had to be used in all cases. Depending on the concentration of hardener and catalyst, differences are observed. TB values increase with the ratio of hardener and catalyst, while activation energies decrease with the amount of catalyst but little changes can be seen when different dianhydride amounts are used. The thermal properties of the final products were unaltered by the hardener used. The decomposition temperature is initiated at a similar temperature in linear and crosslinked PVA, but while uncured PVA undergoes a complete degradation in one step, crosslinked PVA degrades in several steps.
📜 SIMILAR VOLUMES
## Abstract Crosslinked poly(vinyl alcohol) (CPVA) microspheres were first prepared via the suspension polymerization of vinyl acetate and the alcoholysis of poly(vinyl acetate). Afterwards, a two‐step method involving graft polymerization and Hofmann degradation was used to prepare functional poly