US EPA

7755207 

Journal Article 

Sol-gel transition curve of poly(vinylidene fluoride) in organic solvents 

Wada, R; Aihara, K; Nomoto, H; Tazaki, M; Okabe, M 

2000 

1 

Nippon Kagaku Kaishi
ISSN: 0369-4577
EISSN: 2185-0925 

Chemical Society of Japan 

TOKYO 

2000 

11 

797-802 

Japanese 

10.1246/nikkashi.2000.797 

WOS:000165771800006 

It is well known that poly(1,1-difluoroethylene) (hereafter named poly(vinylidene fluoride) (PVdF)) dissolved in some ketones or lactones at high temperature forms a thermoreversible gel in the vicinity of room temperature. In this study, the interaction parameter (χ12) between PVdF and solvent was estimated as a function of temperature by an inverse gas chromatography (IGC) method. The correlation between gelation of PVdF solution and the magnitude of χ12 value was discussed. The solvents used were hexane, cyclohexanone, γ-butyrolactone, and N,N-dimethylformamide. Moreover, sol-gel transition curve was determined for four samples with different molecular weights. The interaction parameter χ12 obtained for each PVdF/solvent system increased slowly with decreasing temperature. The gelation of PVdF occurred with decreasing temperature for the following two systems: one was the system where the parameter χ12 increased passing through 0.5 such as the system PVdF/cyclohexanone; the other was the system where χ12 approached 0.5 such as the system PVdF/ γ-butyrolactone. The sol-gel transition curve shifted to lower concentration with increasing molecular weight.