Biodegradable green composites reinforced by the fiber recycling from disposable chopsticks

The use of disposable chopsticks is very popular in chopsticks-using countries, such as Taiwan, China and Japan, and is one of the major sources of waste in these countries. In this study, the fiber recycling from disposable chopsticks was chemically modified by coupling agents. Furthermore, the modified fiber was added to the biodegradable polymer (polylactic acid, PLA), to form novel fiber-reinforced green composites. These composites prepared by melt-mixing method, were examined by scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, and mechanical tests. The results indicated that the Tg of PLA was increased by the addition of fiber, which may improve the heat resistance of PLA. The thermogravimetric analysis of the composites showed that the degradation process of fiber-filled systems started earlier than that of plain PLA, but possessed a higher char yield. Mechanical tests showed that the tensile strength of the composites markedly increased with the fiber content, reaching 115 MPa in the case of being reinforced with 40 phr fiber, which is about 3 times higher as compared to the pristine PLA. Furthermore, this type of reinforced PLA would be more environmental friendly than the artificial additive-reinforced one, and could effectively reduce and reuse the waste of disposable chopsticks.