Miscibility effect of biodegradable aliphatic poly(butylene succinate)/aromatic polycarbonate blends

Biodegradable polymers are gaining attention for applications in drug delivery, tissue engineering, and wound management. Methods for enhancing their potential in these applications include blending biodegradable aliphatic polyester with other biodegradable aliphatic polyester and/or blending aliphatic polyesters with aromatic polyesters to form blends with unique properties. Herein, we report on the effect of a non-biodegradable aromatic polycarbonate (PC) on the physical, mechanical, and thermal properties of biodegradable aliphatic polybutylene succinate (PBS). The PBS/PC blends contained 3, 13, and 27 wt% PC and were prepared by melt extrusion. The FTIR results revealed apparent compatibility between the two polymers. Even though the blends are compatible, the extent of miscibility depends on thermodynamics terms such as enthalpy, entropy, and Gibbs free energy. According to the SEM micrographs, adding 3 wt% PC resulted in a miscible polymer blend. Above this content, phase dispersion was observed. XRD results revealed peak shifts to higher angles and new peaks forming between 25 and 30°. This is related to the interaction between the components in the blends. The crystallinity was also improved at 3 wt% PC and this is consistent with the DSC results. TGA analysis indicated no improvement in the thermal stability of the blends. DMA revealed that at low PC content (3 wt%), there is a marked improvement in the elastic modulus. This study will benefit the field of Polymer Science because if one wants to prepare PBS/PC they will know that they perform optimally at low PC content.