Development of high barrier biodegradable poly(butylene carbonate-co-terephthalate)-based blends with balanced mechanical properties by self-reactive compatibility and co-crystallization

Compatibility and crystal structure are the most crucial factors to affect the mechanical properties of blending materials. In this work, dozens of kilogram-scaled biodegradable polyester poly(butylene carbonate-co-terephthalate) (PBCT) have been synthesized by a 150L pilot plant, and successfully prepared a series of PBCT-based blends with excellent compatibility by self-reactive compatibility without any extra compatibilizer. The tensile results illustrated that blending PBCT with these industrial biodegradable polyesters could significantly improve the mechanical properties, including tensile strength and elongation at break. Based on the analysis of molecular weights, thermal properties, rheology behavior, and long-period structure, it was clear that the compatible mechanism of PBCT-based blends conformed to reactive compatibility. Wide-angle X-ray diffraction indicated that the reactive compatibility facilitated the formation of co-crystallization. Thus, the chain segments’ reactive compatibility and co-crystallization behavior simultaneously improve the mechanical properties of PBCT-based blends. In addition, the improvement of barrier properties of PBCT-based blends indicated that PBCT as a blending material would significantly expand the application scope of biodegradable polyesters and reduce the dependence on compatibilizer.