Food packages and kitchen utensils made of thermoplastic are very popular due to their low production costs. However, thermoplastic is easily degraded at high temperatures and has low mechanical properties. When degraded, thermoplastic produces carcinogenic monomers that can contaminate food. Thus, natural fiber-based composites are introduced. Most commercial products nowadays are made of thermosets that are difficult to degrade. In order to produce fully biodegradable composite materials, we mixed PLA (polylactic acid) pellets with bamboo. PLA is a thermoplastic polyester that is synthesized from the fermentation of plant starch. The mechanical properties of PLA/bamboo composites depend on the surface interaction between PLA and bamboo. Thus, we studied the effect of the chemical treatment of bamboo prior to composite making on the mechanical properties of PLA and bamboo. Furthermore, the morphology of bamboo was varied into powder, fiber, and strip. A four-year-old bamboo trunk was harvested and dried to minimize the moisture content. Then, it is soaked separately in cold water and 5% NaOH for 72 hours. After it is rinsed and re-dried, the fiber and powder of bamboo are extracted through mechanical treatment. The composite is made with 10% bamboo reinforcement by hot press molding technology at 220°C for 40 minutes. The tensile testing shows that only bamboo strips can improve the mechanical properties of composites. Besides, the alkali treatment was found to increase the brittleness of bamboo, causing an increase in modulus elasticity and a decrease in ductility.
DOI: https://doi.org/10.11648/j.ajpst.20230903.12
Publish Year: 2023
