Much work has been done on the preparation and properties of propylene sulphide polymers but there is very little published data on their molecular weight-intrinsic viscosity relations. Eskin and Nesterov (3~ found the relation [rl] -----3"3 x 10-sM o.s6 (dl/g, benzene, 20:) for samples obtained by fractionation of a polymer prepared with a sodium naphthalene catalyst. For the examination of some polymers prepared with cadmium or zinc complex thiol catalysts, it was desirable to relate a series of whole polymers prepared with highly purified reagents. The relationship ['ql = 5"036 x 10 -s M o.Ts (dl/g, benzene, 31') was established from weight average molecular weight data determined by turbidity measurements (at ,~ = 4358 .~) on benzene solutions. This relation was used to calibrate a Waters Associates "Gel Permeation Chromatograph" to obtain further molecular weight data. A bulk-viscosity-molecular weight relation, for M between 5 x 103 and 10 s determined at 30', gave a value of approximately 2 x i0 ~ for the molecular entanglement point of these polymers.
POLYMERS of propylene sulphide prepared by numerous catalyst system (~) have been known for some time, but there is little published information on their viscositymolecular weight relations. Cadmium and zinc thiolate initiators with thiol chain transfer agents have made possible the production of polymers with a controlled molecular weight and functionality; (2) measurements of solution and bulk viscosities and average molecular weights are reported here.