BATCH AND SEMICONTINUOUS EMULSION COPOLYMERIZATION OF VINYLIDENE-CHLORIDE AND BUTYL METHACRYLATE .2. PHYSICAL AND MECHANICAL-PROPERTIES OF COPOLYMER LATEX FILMS

Vinylidene chloride (VDC)-butyl methacrylate (BMA) copolymer latex films of various compositions (83: 17, 60: 40, 33: 67 in mol %), prepared by batch and semicontinuous processes, were investigated for their physical properties by infrared spectroscopy, C-13 solid-state NMR spectroscopy, X-ray diffraction, solubility in various solvents, differential scanning calorimetry (DSC), and water vapor transmission rates (WVTR), and for their mechanical properties by dynamic mechanical spectroscopy (DMS), and tensile strength measurements. Semicontinuous latex films were found to be homogeneous in composition and amorphous in character. On the other hand, batch latex films containing high VDC monomer content were heterogeneous in composition and crystalline in character. These differences were found to reflect the effect of mode of monomer addition during the emulsion polymerization process, and correlated well to the results on kinetics, colloidal, and surface properties of the VDC-BMA copolymer latexes, as described in the first part of this study.