Abstract: | The temperature coefficient of chain dimensions, d ln〈r2〉0/dT, was determined for stereoirregular 1,4-polybutadiene and poly(α-methylstyrene) via dilute solution viscometry. The 1,4-polybutadiene was examined in oligomeric 1,4-polybutadiene (an athermal solvent), and poly(α-methylstyrene) was evaluated under near-theta conditions using 1-chloro-n-alkanes as solvents. Both approaches minimize the potential for influence by specific solvent effects. The resulting temperature coefficients, ?0.10 × 10?3 deg?1 for 1,4-polybutadiene and ?0.30 × 10?3 deg?1 for poly(α-methylstyrene) are in excellent agreement with rotational isomeric state calculations. |