Reactive blending of poly(butylene succinate) and poly(triethylene succinate): characterization of the copolymers obtained

Poly[butylene-co-(triethylene succinate)] block copolymers (PBSPTES), prepared by reactive blending of the parent homopolymers (PBS and PTES) in the presence of Ti(OBu)4, were analysed by nuclear magnetic resonance (NMR), wide angle X-ray diffraction, thermogravimetric analysis and differential scanning calorimetry techniques, in order to investigate the effects of the transesterification reactions on the molecular structure and thermal properties. 1H-NMR analysis evidenced the formation of copolymers whose degree of randomness increased with mixing time. After melt quenching, all the copolymers were found to be semicrystalline with the exception of a random copolymer. The results obtained indicated that the block size has a fundamental role in determining the rate of crystallization and therefore the phase behavior of the block copolymers.