Chiang Mai Journal of Science

      The conventional use and disposal of fossil-based plastics has long been a major environmental problem, as they are not biodegradable and their production consumes a lot of energy. Polylactic acid (PLA), a renewable polymer derived from natural materials, has emerged as a promising alternative as it has comparable properties to conventional plastics and has minimal environmental impact. Rice straw, which is produced in abundance, contains valuable components that could be used effectively in this context. The objective of this research was to investigate the mechanical, characterization, and water stability properties of these synthesized bioplastics. Rice straw fibers (RS) were added in PLA based green bioplastic at different PLA/RS ratios of 2:1, 3:1, 4:1, and 1:0 wt/wt with 5% plasticizer based on the total solid. The compositions were mixed in an internal mixer and molded in a compression molding process to produce bioplastics. The samples were analyzed for tensile strength, elongation at break, water solubility, water absorption, contact angle, SEM and TGA. The optimum condition for the production of the bioplastic was a 2:1 ratio of PLA/RS with 5% triacetin, resulting in a tensile strength of 58.1 MPa, a water absorption of 1.55% and a water contact angle of 102.8°. SEM analysis showed that the RS exhibited robust adhesion of the RS in the PLA matrix. The biodegradability of the bioplastic was dependent on the RS content and the degradation time. The bioplastic can be reinforced with rice straw material and is potentially suitable for packaging applications at temperatures below 270°C.