Esterification of Microfibrillated Cellulose with Various Anhydrides to Improve Thermal and Mechanical Properties of Polylactic Acid Composite

Microfibrillated cellulose (MFC) has been discovered as reinforcement for polylactic acid (PLA) composite. This composite could replace petroleum-based polymer for automotive and electronic purposes. Hydrophilicity of MFC makes the fibers do not uniformly dispersed at the hydrophobic PLA matrix and it gives adverse effect to thermal and mechanical properties. In this study, MFC was esterified with acetic anhydride, butyric anhydride, and maleic anhydride to improve the intended properties. The success of esterification was proved by infrared spectrophotometry and supported by degree of substitution value. Prior to preparing the PLA composites, the water content in MFC and it ester was reduced using solvent inclusion with ethanol, acetone, and dichloromethane. The composites were prepared by mixing PLA (molecular weight of 200,000) and the esterified MFC at 9:1 ratio. Followed by 8 minute-kneading and hot pressing at 180 C, thermal and mechanical properties of the samples were tested. Differential scanning calorimetry analysis indicated that the presence of MFC-butyrate accelerates the crystallization of PLA. The tensile strength and maximum strain were improved by the MFC-maleate reinforcement at PLA matrix, but modulus of elasticity was improved by MFC-acetate. Carbon chain length and double bond carbon at MFC esters give different effect to thermal and mechanical properties. Proceeding International Seminar on Sciences (ISS), FMIPA, IPB. P: 155 ISSN: 978-979-95093-9-0