Thermoplastic composites between polybutylene succinate and recycled PET adding hollow glass microspheres

Use of biodegradable polyester-based polymers in various applications has been extensively carried out in the past decades. Blending recycled poly(ethylene terephthalate) (r-PET) would be an alternative way to improve mechanical rigidity, reduce cost of the blends, and integrate recycle route with renewable resource. In this research, we attempted to prepare poly(butylene succinate) (PBS)/recycled PET (PBS/r-PET) blends via melt blending in various blend ratio (90:10, 80:20, and 70:30 wt%) and then melt compounded with hollow glass microspheres (HGM) (3, 5 and 10 wt%) to obtain thermoplastic composites that would be used in electrical or electronic applications. Mechanical properties of blends and their composites were evaluated by means of tensile and notched Izod impact tests. Compatibility and thermal behavior were characterized using DSC and TGA. Morphology of fractured specimens was studied using SEM. It was found that PBS/r-PET blends exhibited higher tensile modulus with respect to r-PET content; however, toughness of the blends was deteriorated from poor interfacial attraction and molecular weight reduction of PBS matrix. T_g of PBS phase was shifted to higher temperature because of transesterification. The composites had higher specific tensile modulus with respect to HGM loading. With the presence of r-PET, HGM surface was wetted implying r-PET acted as compatibilizer between hydrophobic PBS matrix and hydrophilic HGM, and thus, tensile modulus of composites was 10–40% increased depending on HGM loading.