Morphology Evaluation of Biodegradable Copolyesters Based on Dimerized Fatty Acid Studied by DSC, SAXS and WAXS

Aliphatic copolyesters of succinic acid (SA) and dimerized fatty acid (saturated dilinoleic acid (DLA)) were synthesized via direct copolycondensation in the presence of 1,4-butane- diol. The thermal and mechanical properties of these copolymers were investigated as a function of the hard/soft segments' ratio. The results of small-angle X-ray scattering (SAXS) investigations revealed that the characteristic d spacing of the copolyester supermolecular structure increases from 7 nm to 14 nm with increasing content of soft segments, DLA. It was found that the crystalline phase content determined by WAXS increases from 22 to 66% and was found to increase with increasing content in polybutylene succinate (PBS) se- quences and increasing polybutylene succinate (PBS) sequence length. Also, it was shown that the synthesized polymers are susceptible to biodegradation and that the highest mass losses occurred for copolymers of lower crystallinity.