Dipole Moment of The Poly(thiocarbonate) of 2,2’-bis(4-hydroxyphenyl)propane

The dipole moment of the poly(thiocarbonate) of 2,2^/-bis(4-hydroxyphenyl)propane (PMTC) has been determined in 1,4-dioxane solution at 25 °C. The “effective” dipole moment of a sample having M_n= 7.0 X 10³(i.e. x = 30 repeating units) was found to be μ_eff= (μ²)/x)^1/2= 0.97 D. Theoretical calculations were performed using the rotational isomeric state model with the scheme developed by other authors for polycarbonates. The calculated values of μ_effare almost insensitive to the conformational parameters used in the calculations. Agreement between theoretical and experimental results is obtained, assuming that the end groups of the chains have dipole moments of ca. 1.5 D, which is roughly the dipole moment of the phenolic residues that the procedure of synthesis attaches to the polymeric chain.