SOLUTION PROPERTIES OF ULTRAHIGH-MOLECULAR-WEIGHT POLYMERS - 21 - CONFORMATIONAL CHARACTERISTICS OF POLY(METHYL METHACRYLATE)

The behavior of ultrahigh-molecular-weight poly(methyl methacrylate) ( M-w = 9.564 x 10(6) to 23 x 10(6)) in dilute solution in toluene, chlo roform, and dimethylformamide at 25 degrees C has been investigated by viscometry; the chloroform solutions were also studied by light scatt ering at 20 degrees C. The corresponding Mark-Houwink relations have b een established and the unperturbed dimensions have been determined by the extrapolation methods of Lenka, and Stockmayer-Fixman and Burchar d. A correction term, depending on the a exponent of the Mark-Houwink relation, was proposed to be introduced into the Stockmayer-Fixman-Bur chard equation. The correlation between this correction term and the f lexibility of polymethacrylates is discussed using present and previou s data.