| Abstract: | Raman spectroscopy has been used to study PVC gels made in cyclohexanone in the wet state at concentrations from 21 to 93% by weight of PVC. Parallel and perpendicular spectra were obtained in the C-Cl stretching region, and after subtraction of the solvent spectrum they were analyzed into a set of overlapping peaks due to various structural components. The positions of the peaks found were in good agreement with those found earlier for PVC samples in the solid state. The fractional contribution of the areas of peaks assigned to crystalline material to the total area under the C-Cl stretching region was used to estimate the crystallinity of the gels, and changes in their depolarization ratios and relative intensities were interpretated as providing further evidence for the presence of two types of crystallites in PVC gels. From a determination of the crystallinity at the gel transition point and reasonable assumptions, the contributions of the two types of crystallites to the total crystallinity were estimated. |
