Mechanical and nonisothermal cold crystallization behaviors of injection molded surface-modified chitin whiskers/poly(l-lactide) composites

To improve the mechanical, crystallization performances of poly(l-lactide) (PLLA), pristine and surface grafted chitin whiskers (CWs and g-CWs) were introduced to PLLA via melt blending. Attributed to the good interfacial compatibility between the g-CWs and PLLA matrix, the tensile, flexural, and impact performances of the g-CWs/PLLA composites were better than that of the CWs/PLLA composites with the same whiskers content. The whiskers acted as nucleating agents to promote the crystallization of the PLLA matrix on the one hand, and acted as obstacles to restrict the crystals growth on the other hand. The nonisothermal cold crystallization kinetics revealed that the crystallization rate and crystallinity of the PLLA matrix were improved by the addition of the whiskers, but the promotion effect of g-CWs was more obvious than CWs.

Automated summary

By introducing surface-grafted chitin whiskers via melt blending, the mechanical and crystallization performances of PLLA were improved. The whiskers acted as nucleating agents to promote PLLA crystallization and as obstacles to restrict crystal growth, with grafted chitin whiskers showing a more obvious promotion effect compared to pristine chitin whiskers.