Synthesis of Poly(ester amide)s Derived from Glycolic Acid and the Amino Acids: β‐Alanine or 4‐Aminobutyric Acid

Abstract

The polymerization of metal salts of N‐chloroacetyl‐β‐alanine and N‐chloroacetyl‐4‐aminobutyric acid was investigated. The former gives a mixture of polymer and a seven‐membered cyclic compound constituted of glycolic and β‐alanine units, and its reaction proceeds in the solid state. However, liquefaction is observed in the second case giving rise to a polymer with a moderate molecular weight. Condensation kinetics of both sodium and silver salts of N‐chloroacetyl‐β‐alanine have been studied by differential scanning calorimetry. Copolymers of glycolic acid and β‐alanine with a molar ratio of glycolic acid/β‐alanine varying from 0.5 to 1.0 have been synthesized by thermal reaction of co‐precipitated crystals of the sodium salts of chloroacetic acid and N‐chloroacetyl‐β‐alanine. NMR spectroscopy indicates that copolymers tend to have a random distribution. The resulting new poly(ester amide)s have been characterized by spectroscopy and thermal analysis.DSC heating runs corresponding to different mixtures of the sodium salts of chloroacetic acid and chloroacetyl‐β‐alanine.magnified imageDSC heating runs corresponding to different mixtures of the sodium salts of chloroacetic acid and chloroacetyl‐β‐alanine.

New Method of Synthesis of Poly(ester amide)s Derived from the Incorporation of Glycolic Acid Residues into Aliphatic Polyamides

“…The molecular weight is adequate to give good film‐ and fibre‐forming properties, as demonstrated by the corresponding X‐ray diffraction patterns (Figure 3c). These results clearly improve our previous work on β ‐alanine derivatives14 where polymerization competes with a cyclization reaction.…”

Synthesis and Characterization of Poly(glycolic acid‐alt‐6‐aminohexanoic acid) and Poly(glycolic acid‐alt‐11‐aminoundecanoic acid)

“…Cyclization reactions become important when the number of methylene groups is low. Thus, the seven‐membered ring of 4‐oxo‐azepan‐2,5‐dione is mainly obtained from the derivative of β ‐alanine 17. However, polymers with high molecular weights can be easily prepared when cycles are less stable, as is the case of the aminohexanoic derivative 18.…”

Novel Biodegradable Copolymers with a Periodic Sequence Structure Derived from Succinate Butan‐1,4‐diol, and Butan‐1,4‐diamine

“…Many types of aliphatic polyester‐amides have been synthesized by various techniques 1–20. Copolymers with random, multi‐block, or alternative distributions of ester and amide groups were produced by bulk‐, melt‐, and solution polycondensation reactions, and the ester‐amide interchange reaction, and the structures, physical properties, and degradabilities of these polyester‐amides were characterized.…”