SYNOPSISBiodegradable poly( 1,4-butanediol succinate) was synthesized from 1,4-butanediol and succinic anhydride. The synthesized polymer was identified by 'H-NMR spectrometer and FT-IR spectrophotometer. The weight average molecular weights were between 4,600 and 29,000, and molecular weight distributions were in the range of 1.7 and 1.9. The glass transition temperature of poly( 1,4-butanediol succinate) was revealed at 73'C. The crystallization and cold crystallization of the polymers were investigated as a function of heating rate, cooling rate, reheating rate, and molecular weight. The biodegradation behavior of poly( 1,4-butanediol succinate) in micro-organisms such as fungi, actinomycetes, and bacteria was studied by using modified ASTM method. Based upon visual observation, the crystalline structure of films composed of larger molecular weight polymers retained their crystallinity longer than similar structures in low molecular weight samples. 0 1995

Biodegradable poly(1,2‐propanediol succinate) and poly(1,3‐propanediol succinate) were synthesized using 1,2‐propanediol and 1,3‐propanediol with succinic anhydride, respectively. The synthesized polymers were identified by NMR spectrometry and FT‐IR spectrophotometry. The weight average molecular weights were 8,900 in poly(1,2‐propanediol succinate) and 8,600 in poly(1,3‐propanediol succinate), respectively. The biodegradation behavior of polymers in microorganisms was studied by using a modified ASTM method. These polyesters were degraded to lower molecular weight compounds depending on hydrophobicity and hydrophilicity. The quantitative determination of carbon dioxide, generated during the treatment with the activated sludge, showed that poly(1,3‐propanediol succinate) was biodegraded faster than poly(1,2‐propanediol succinate). The biodegradation ability of the polymers by Aspergillus niger was monitored to check the molecular weights using GPC and to check the crystallinity change of the polymers using DSC. Based upon the visual observation of the biodegraded polymers, the crystalline structure of poly(1,2‐propanediol succinate) apparently retained its crystallinity longer than the similar structure in poly(1,3‐propanediol succinate).

New polyesters were synthesized using Krebs cycle acids. Poly(1, 4‐butanediol dilactate succinate)(PBDS) and poly(1, 4‐butanediol dilactate 2‐acetoxy succinate)(PBDAS) were prepared by the polycondensation of 1, 4‐butanediol dilactate with succinic anhydride and 2‐acetoxy succinic acid, respectively. Poly(1, 4‐butanediol succinate)(PBS) was also synthesized from 1, 4‐butanediol and succinic anhydride. PBS/PBDS and PBS/PBDAS blends were prepared by the method of solvent casting. The effects of crystallization time and temperature onto melting behavior of PBS/PBDS and PBS/PBDAS blends were investigated by differential scanning calorimetry. The compatibility of each blend system was discussed using equilibrium melting point depressions. The biodegradation behavior was studied using PBS, PBDS, and PBDAS as the sole carbon source by Aspergillus niger. The molecular weights of the polymers which were obtained from GPC analysis decreased after degradation in five weeks.