Poly(vinylidene fluoride) poly(vinyl alcohol-co-vinyl acetate) blends: 2. Study by infrared spectroscopy

Blends of poly(vinylidene fluoride) (PVDF) and some poly(vinyl alcohol-co-v inyl acetate) copolymers (PVAAc) with various molecular weights and acetate contents are studied by Fourier transform infrared spectroscopy (FTIR). Fi rst. two sets of blends of PVDF with two different copolymers at various co ncentrations are analysed. Then, 50/58 (wt/wt) blends of seven PVAAc with P VDF are studied. Two carbonyl bands are observed corresponding to free and bonded carbonyls. The rate of bonded carbonyls and the interaction enthalpi es are determined. The results are in good agreement with the occurrence of a rather strong interaction between the carbonyls of the residual acetate groups and the hydroxyl groups of the copolymers. No interaction between th e carbonyls and PVDF were observed. The experimental results are in a good agreement with the foresights of the Coleman-Graf-Painter interaction model . (C) 1998 Elsevier Science Ltd. All rights reserved.