Facile and Large-scale Fabrication of Biodegradable Thermochromic Fibers Based on Poly(lactic acid)附视频

To investigate the feasibility of developing biobased and biodegradable thermochromic fibers, poly(lactic acid)(PLA) fibers with visual temperature indicator functionality were fabricated using a scalable melt spinning technique(spinning speed 800 m/min), where PLA and thermochromic microcapsules were used as fiber-forming polymers and color indicators, respectively. The effect of thermochromic microcapsules on the mechanical properties and reversible color-changing function of PLA fibers was systematically investigated to achieve high tenacity and sensitive color-changing function. The difference in the fiber performance was connected to changes in the multilayer structure. The results show that PLA fibers exhibit excellent tenacity of 3.7-4.7 cN/dtex and reversible and stable thermochromic behavior over 31 ℃. The high fraction of mesophase within TPLA-1 fiber plays an important role in its tenacity. Meanwhile, the low-concentration of microcapsules(～1 wt%)with good dispersion could act as a nucleating agent inside the PLA matrix and contribute to the formation of microcrystals in the amorphous between primary lamellae, which is also beneficial to maintain the tenacity of the fibers. The agglomeration of high-concentration microcapsules within PLA fibers hampered the formation of mesophase, resulting in a decrease in fiber tenacity. Aside from the content of microcapsules, the agglomeration of high-concentration microcapsules(>5 wt%) is the main reason that limits the substantial increase in fiber color depth. This study opens up new possibilities for degradable thermochromic fibers produced using standard industrial spinning technology.