Poly(ester amide)s Derived from l-Tartaric Acid and Amino Alcohols. 1. Regic Polymers

Abstract

Stereoregular poly(ester amide)s (PEATn) containing equal amounts of ester and amide groups have been obtained by polycondensation in solution from di-O-methyl-l-tartaric acid and aliphatic amino alcohols H2N(CH2)n-1CH2OH. Suitable synthetic routes were designed to prepare either syndioregic (s-PEATn, n = 5,6) or isoregic (i-PEATn, n = 5, 6, 11) polymers. All the newly synthesized poly(tartarester amide)s were characterized by elemental analysis, size exclusion chromatography, and IR and NMR spectroscopies. They all display optical activity in solution and, except for s-PEAT5, are highly crystalline with Tm's within the range 100−150 °C and Tg's oscillating between 10 and 30 °C. Thermal decomposition of PEATn onsets above 200 °C with Td values depending upon both the regicity of the chain and the length of the polymethylene segment. For comparative purposes, two poly(esteramide)s, one syndioregic (s-PEAS6) and another isoregic (i-PEAS6), were prepared from succinic acid and 6-amino-1-hexanol, and their properties were evaluated in parallel. Major differences between PEAS6's and PEAT6's concerned solubility and hygroscopicity whereas crystallinity and thermal transitions were found to be scarcely affected by the presence of the methoxy side groups.