A critical angle illumination microscopy technique was used to study the in situ dissolution dynamics of polystyrene, poly (α‐methylstyrene) and the two tactic forms of poly (methyl methacrylate), (PMMA), in several solvents. The dissolution characteristics; of polymers were found to be greatly influenced by several factors: type of polymer, processing condition of the sample, type of solvent, and tacticity, Polystyrene was found to exhibit extensive swelling in several solvents while atactic PMMA exhibited extensive cracking on dissolution. Isotactic PMMA, which has a glass temperature of about 70°C lower than the atactic PMMA, showed swelling behavior similar to atactic polystyrene, while the α‐methylstyrene showed the cracking phenomena exhibited by atactic PMMA.

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Publication costs assisted by IBM CorporationA physical description of the dispersion of solutes in Poiseuille flow and its analogy to Fickian diffusion is presented. The superior accuracy of the computerized data acquisition and processing technique over the graphical method of obtaining diffusion coefficients from the retention volume distribution (RVD) of solutes in capillaries is demonstrated. The diffusion coefficients of various organic compounds in chloroform at different temperatures were measured and activation energies calculated.

Laboratory, Sun Jose, California 95193[article in J. Appl. Polym. Sci., 27,3449-3454 (1982)] On p. 3451, the last sentence in the second full paragraph should read as follows: "This is less than 10% of the measured intensity of the resonances between 115 and 131 ppm, which indicates that all other ring carbons in the structure are counted."On p. 3452, the first full sentence should read as follows: "The average number of repeat units (15.85/6.6 = 2.4) X 2 = 4.8, results in a calculated molecular weight of 804, which is within 11% of the vapor phase osmometer result."

Laboratory, Sun Jose, California 95193[article in J. Appl. Polym. Sci., 27,3449-3454 (1982)] On p. 3451, the last sentence in the second full paragraph should read as follows: "This is less than 10% of the measured intensity of the resonances between 115 and 131 ppm, which indicates that all other ring carbons in the structure are counted."On p. 3452, the first full sentence should read as follows: "The average number of repeat units (15.85/6.6 = 2.4) X 2 = 4.8, results in a calculated molecular weight of 804, which is within 11% of the vapor phase osmometer result."