Preparation of thermochromic bioplastic composite filaments for 3D printing process

Abstract

This research aimed to produce thermochromic composite filaments by utilizing poly(lactic acid) (PLA) as a matrix and two distinct thermochromic additives (red and yellow colors). To produce thermochromic composite filaments with ratios ranging from 10 to 40 phr, different quantities of a thermochromic masterbatch were integrated into the PLA matrix through an extrusion process. The physical, mechanical, thermal properties, and thermochromic behavior of the composite filaments were further examined. The results indicated that the thermochromic additives had minimal impact on thermal and mechanical properties, while also revealing a two‐phase separation between the smooth matrix and the spherical particle additives in the thermochromic composite filaments. Moreover, the analysis of thermochromic behavior revealed that an increase in the ratio of thermochromic masterbatches led to more pronounced coloration and clearer color changes, especially with red and yellow thermochromics indicating temperature variations below 22°C and over 65°C, respectively. The sample containing 40 phr exhibited the most intense color and noticeable color change. Furthermore, these thermochromic composite filaments can be utilized to 3D print various prototype products.Highlights Thermochromic bioplastic composite filaments for 3D printing were successfully prepared. The thermochromic behavior analysis unveiled vivid coloration with distinct and more pronounced color changes.