ION-FREE LATEX FILMS AS DUAL-PHASE ELECTROLYTES - STYRENE-BUTADIENE RUBBER AND NITRILE-BUTADIENE RUBBER SYNTHESIZED BY EMULSION POLYMERIZATION WITH POLY (VINYL PYRROLIDONE) STABILIZER

Ion-free latices of styrene-butadiene rubber (SBR) and nitrile-butadiene rubber (NBR) were synthesized by emulsion polymerization with use of poly(vinyl pyrrolidone) (PVP) stabilizer. The goal was to prepare ion-free latex films, possessing dual-phase latex particle morphology, and swell the films with liquid electrolyte to yield dual-phase polymer electrolytes (DPE). SBR/PVP latex was prepared readily, but NBR/PVP latex was sensitive to coagulation. Differential scanning calorimetric (DSC) and scanning electron microscopic (SEM) analyses of latex films provided morphological evidence concerning particle structure and phase separation. Blends of NBR/PVP and PB/PVP latices (PB = polybutadiene) were also investigated, but particle structure was not present in the blended latex film, even though particle structure was present in the individual NBR/PVP and PB/PVP latex films. After extensive swelling of SBR/PVP latex films, PVP was extracted from the films, and ionic conductivities greater than 10(-3) S/cm were achieved. (C) 1994 John Wiley & Sons,Inc.