Vinylidene fluoride solvent effect

Yoo M, Frank CW, Mori S, Yamaguchi S (2004) Interaction of poly(vinylidene fluoride) with graphite particles. 2. Effect of solvent evaporation kinetics and chemical properties of PVDF on the surface morphology of a composite film and its relation to electrochemical performance. Chem Mater 16 1945-1953. doi 10.1021/cm0304593... 

The radiation-initiated polymerization of vinylidene fiuoride is used on a laboratory scale only. The effect of polymerization conditions on the chain defects, content, and changes in the crystalline phases have been studied [528,536,537,544]. Doll and Lando [544] used a °Co source with an average dose rate of 0.33 Mrad/h. The polymerization was carried out between 0 and 400 °C at a pressure equal to the vapor pressure of the solvent-vinylidene fluoride mixture. Esters and ketones (acetone, methyl ethyl ketone, ethyl acetate, acetophenone), DMF, DMSO, and y-butyrolactone were used as solvents. All these solvents are good chain-transfer agents for vinylidene fluoride. The molding characteristics of the resulting polymers were very poor and the intrinsic viscosity of the sample polymerized in acetone solution was low (0.183 dL/g) compared to that of a suspension-polymerized polymer (1.68 dL/g) [544]. 

M.L. Yeow, Y.T. Liu, and K. Li. (2004). Morphological study of poly(vinylidene fluoride) asymmetric membranes Effects of the solvent, additive, and dope temperature, J. Appl. Polym. ScL 92 1782-1789. 

From Eq. (3.1) to Eq. (3.3), surface tension, viscosity, and ambient temperature are parameters that will have an effect on the measured contact angle. While viscosity will primarily influence the rate of relaxation of 0d during wetting, surface tension will have effects on both the relaxation rate Eq. (3.2) and the final contact angle Eq. (3.1). Surface tension is a property of liquid caused by uneven attraction of liquid molecules (or surface cohesion) at or near the surface, the higher the surface tension, the larger the resistance for the liquid to wet. The effect of solvent on contact angle has been studied on many polymer surfaces, such as poly(tetrafluoroethylene), poly(vinylidene fluoride), poly(ethylene), poly(vinyl chloride), poly(vinylidene chloride), polystyrene, and the like and adsorbed monolayers from aliphatic fatty acids and perfluoro fatty acids. The subject was summarized well by Zisman [2]. The solvent effect is usually plotted as cos 0 versus /lv of the liquid. A typical plot... 

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