Glycol ethers properties/recovery

The low-molecular weight depolymerizates can be introduced directly into a polymerization system,preferentially after filtration. In this method, particular care has to be taken in order to avoid glycol ether formation, which may lead to PET of inferior properties. The glycol5dic degradation can also be pushed to further completion, leading to DGT-recovery, rather than to direct re-use. 

Physical properties are related to ester-segment structure and concentration in thermoplastic polyether-ester elastomers prepared hy melt transesterification of poly(tetra-methylene ether) glycol with various diols and aromatic diesters. Diols used were 1,4-benzenedimethanol, 1,4-cyclo-hexanedimethanol, and the linear, aliphatic a,m-diols from ethylene glycol to 1,10-decane-diol. Esters used were terephthalate, isophthalate, 4,4 -biphenyldicarboxylate, 2,6-naphthalenedicarboxylate, and m-terphenyl-4,4"-dicarboxyl-ate. Ester-segment structure was found to affect many copolymer properties including ease of synthesis, molecular weight obtained, crystallization rate, elastic recovery, and tensile and tear strengths. 

---