Biodegradable homopolyesters such as poly(butylene succinate) (PBSU) and poly(butylene adipate) (PBAD) and copolyesters such as poly(butylene succinate‐co‐butylene adipate) (PBSA) were synthesized, respectively, from succinic acid (SA) and adipic acid (AA) with 1,4‐butanediol through a two‐step process of esterification and deglycolization. The polyester compositions and physical properties of both homopolyesters and copolyesters were investigated by 1H– and 13C–NMR, DSC, GPC, WAXD, and optical polarizing microscopy. The melting point (Tm) of these copolyesters decreased gradually as the contents of butylene adipate increased and the glass‐transition temperature (Tg) of these copolyesters decreased linearly as the contents of the adipoyl unit increased. PBSA copolyesters showed two types of XRD patterns of PBSU and PBAD homopolyesters. Furthermore, the biodegradation and hydrolytic degradation of the high molecular weight PBSU homopolyester, PBAD homopolyester, and PBSA copolyesters were investigated in the composting soil and NH4Cl aqueous solutions at a pH level of 10.6. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2808–2826, 2001

Biodegradable homopolyesters such as poly(butylene succinate) (PBSU) and poly(butylene adipate) (PBAD) and copolyesters such as poly(butylene succinateco-butylene adipate) (PBSA) were synthesized, respectively, from succinic acid (SA) and adipic acid (AA) with 1,4-butanediol through a two-step process of esterification and deglycolization. The polyester compositions and physical properties of both homopolyesters and copolyesters were investigated by 1 H-and 13 C-NMR, DSC, GPC, WAXD, and optical polarizing microscopy. The melting point (T m ) of these copolyesters decreased gradually as the contents of butylene adipate increased and the glass-transition temperature (T g ) of these copolyesters decreased linearly as the contents of the adipoyl unit increased. PBSA copolyesters showed two types of XRD patterns of PBSU and PBAD homopolyesters. Furthermore, the biodegradation and hydrolytic degradation of the high molecular weight PBSU homopolyester, PBAD homopolyester, and PBSA copolyesters were investigated in the composting soil and NH 4 Cl aqueous solutions at a pH level of 10.6.

Synthesis of 3-Amino-4-methylidene-2-azetidinone via a Thermal Elimination Reaction.-The probably antimicrobial active title compound (IX), in its N-protected form, is synthesized in 10 steps starting from the trans-azetidinone (III), which is exclusively formed in the (2 + 2) cyclization of compounds (I) and (II). Attempted deprotections with CF3COOH as well as H2/Pd do not give the desired title compound, thus requiring further studies. -(KIM, S. H.; NAM, G.; JANG, E. S.; CHI, D. Y.; KIM, J.-H.; Bull. Korean Chem.

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ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.