The relationship between the molecular weight and intrinsic viscosity of polystyrene

Abstract

AbstractThe polymerization of styrene using γ,γ′‐azo (γ‐cyano‐n‐valeric acid) as initiator was studied at 100°C. in DMF solution.It has been shown that the rate of polymerization is proportional to the square root of the initiator concentration and 3/2 power of the monomer concentration. The chain‐transfer constant for styrene radicals and dimethylformamide has been determined at 100°C., with the result Cs = 1.08 · 10−4.Several samples of polystyrene of low molecular weights (below the osmotic pressure range) were prepared under a variety of conditions in the presence of this initiator. Their molecular weights were determined by viscosity and end group titrations, both for fractionated and unfractionated samples. The results are compared with those obtained by other workers.