The study of environmental stabilization for natural color dyed of eggshell powder filled in polylactic acid bio-composites

Abstract

This research aimed to study the environmental stabilization for bio-composites. The weight content of eggshell powder (ESP) was set 5% by weight into the polylactic acid (PLA) matrix. Two natural colors of Sappan wood (red color) and Jackfruit tree (yellow color) were dyed into ESP. PLA was compounded with ESP and natural color dyed of ESP in the internal mixer and fabricated by injection molding. The specimens were tested light-radiation exposure to Rayong’s climate for 15 and 30 days. The physical changes in color, functional group analysis, and mechanical properties of specimens before and after exposure were determined. These results indicated that natural colors dyed ESP filled PLA, bio-composites changed the appearances of color variations more than ESP filled PLA. However, ESP and natural colors dyed of ESP did not affect functional group positions after light exposure testing, but the significant change concerned bands between 1800 and 1680 cm−1 that attributed to the carbonyl group in PLA. Crystallization behavior revealed that the Tg of specimen tended to decrease after exposure testing. Furthermore, the yellow dyed from Jackfruit tree would encouragement the crystallization that was seen a slight development in the %crystallinity of the PLA-ESP biocomposites. The tensile strength of all samples would be increased with after light exposure, but %strain at break of PLA and ESP filled PLA decreased with light exposure. On the other hand, the elongation of two natural colors dyed of ESP filled PLA tended to increase after 30 days of light exposure when compare with neat PLA.