Liquid Metal as a Liquid State Nucleating Agent for Poly(l-lactide)

This work for the first time reports that liquid metal (LM, gallium) behaves as a nucleating agent for the plastic poly(l-lactide) (PLLA). The LM-PLLA composites with different content (0-10%, by weight) of LM are fabricated by a twin crew extruder. The impacts of LM content on non-isothermal and isothermal crystallization behavior are systematically investigated by calorimetry combing with Avrami's theory, determining an optimal LM content (2.5%) for advancing the crystallization of PLLA. Wide-angle X-ray diffraction (WAXD) shows that the excessive LM will interfere with the crystal structure of X%LM-PLLA. As a kind of liquid state nucleating agent in plastic, the nucleation mechanism of LM for PLLA is attributed to the production of carboxylate ion clusters from the reaction between carboxylic acid on the end group of the PLLA chain and gallium, which is distinct from the epitaxy mechanism of previous solid nucleating agents.

Automated summary

This study reports for the first time that liquid metal (gallium) acts as a nucleating agent for plastic poly(l-lactide) (PLLA). LM-PLLA composites with different weight percentages of LM (0-10%) are fabricated using a twin screw extruder. The influence of LM content on non-isothermal and isothermal crystallization behavior is investigated systematically using calorimetry and Avrami's theory, revealing an optimal LM content of 2.5% for enhancing PLLA crystallization. Wide-angle X-ray diffraction (WAXD) analysis shows that excessive LM interferes with the crystal structure of X%LM-PLLA. Unlike previous solid nucleating agents, the nucleation mechanism of LM for PLLA is attributed to the production of carboxylate ion clusters through the reaction between carboxylic acid on the end group of the PLLA chain and gallium, rather than epitaxy mechanism.