Synthesis of sago starch laurate in densified carbon dioxide

Fatty acid starch esters are potential candidates for novel biodegradable plastics. This work describes a systematic study on the synthesis of starch laurate using sago starch and vinyl laurate (VL) in densified CO2 as a green solvent. The phase behavior of the CO2–VL system was investigated in a high pressure view cell and the critical point of the CO2‐VL mixtures was shown to increase with temperature. Within the experimental window, sago starch laurate with a maximum degree of substitution (DS) of 0.97 is obtained. To the best of our knowledge, such high DS values have never been reported before for reactions in densified CO2. Moreover, the presence of laurate chains in the starch backbone has a profound influence on the degree of crystallinity, the melt and crystallization temperature, and the degradation temperature of the final products. POLYM. ENG. SCI., 58:291–299, 2018. © 2017 Society of Plastics Engineers