| Abstract: | The structure and properties of a ternary polymer system comprised of 1, 4 polybutadiene, cis 1, 4 polyisoprene, and the corresponding 1, 4 polybutadiene/cis 1, 4 polyisoprene diblock copolymer have been investigated. Dynamic mechanical properties were measured as a function of frequency (3.5 to 110 Hz) and temperature (?135 to 40°C). Thermomechanical analysis and transmission electron microscopy provided additional information on the, phase relationships in the various specimens. The blends studied covered the entire triangular composition diagram; both slow solvent evaporation and rapid spin casting techniques were employed in the sample preparation. Results indicate that the BI diblock is a single phase material whereas binary blends of the two homopolymers are two-phase in nature. Ternary blends of the two homopolymers with diblock and binary blends of a single homopolymer with diblock can be one or two phase materials depending on the sample composition and the ratio of B to I units in the diblock. All evidence From the dynamic, thermomechanical and microscopic experiments is used to elucidate the influence of the diblock in these polymer blends. |
