Studies on Polyesters

I. Action of Metallic Salts in Polyester Synthesis

Abstract

The role of metallic salts in polyester synthesis were discussed. If the reaction products from metallic salts and the initial components of polyester act as an accelerator, then reaction will be promoted, when the metallic salts are replaced by the reaction products. The reaction product (A) of ethyleneglycol (EG) and Zn was prepared from EG and zinc acetate, and that (B) of dimethylterephthalate (DMT) and Zn was from DMT and zinc acetate in dimethylformamide solution. As a reaction accelerator, zinc acetate or the above reaction product is added to the mixture of the definite composition of DMT, EG and glycerine. All synthesis tests were done under the same condition. During the condensation, the changes of OH value, acid value and viscosity with time were measured. The effects of zinc acetate, A and B on OH value, acid value and viscosity were compared, under the same concentration of Zn. With regard to accelerating action, A is comparable to zinc acetate and is more effective than B.
The metallic salts are expected to have an accelerating property for polyester synthesis, after these react with EG and DMT.