Properties and Soil Degradation Characteristics of Chitin-Reinforced Poly(butylene succinate)/Hydroxyapatite Composites

Poly(butylene succinate) (PBS) is a biodegradable polymer; however, a prolonged soil degradation rate of PBS limits its wide range of applications. Here, the impact of incorporating chitin in mechanical and thermal properties and soil degradation characteristics of PBS/hydroxyapatite (HAP) composites is investigated. Chitin is one of the most abundant natural polymers extensively used for various applications and has a fast soil degradation characteristic. Therefore, ternary PBS composites are melt-processed in a twin-screw extruder with a fixed amount of HAP (1.5 wt%) and two different loadings of chitin (1.5 and 3 wt%). Morphological characterization using transmission electron microscopy shows a homogeneous distribution of both fillers in a PBS composite containing 1.5 wt% chitin. In contrast, an optical microscopy study of the same composite at the melt state shows defibrillation and breakage of the chitin fibers during the extrusion. Incorporation of chitin decreases the elongation at break of the PBS/HAP composite, which is likely a consequence of chitin fiber morphology. However, the soil degradation characteristics and melt strength of PBS/HAP composites are improved in the presence of chitin fibers. In summary, chitin is shown to have the potential as an additive to obtain environmentally benign PBS composites for a wide range of applications.

Automated summary

The impact of incorporating chitin in PBS/HAP composites on their mechanical and thermal properties, as well as soil degradation characteristics, was investigated. Chitin was found to improve the soil degradation characteristics and melt strength of the composites, while decreasing their elongation at break.