Preparation and properties of bamboo fiber/polylactic acid composite modified with polycarbodiimide

Bamboo fiber (BF) is favored by people for its renewability, low cost, fast growth, low density, high hardness, pollution -free, and easy harvesting. However, when preparing composites by blending and extruding BF and degradable plastic PLA, the significant difference in polarity between the two leads to a significant decrease in mechanical properties, which limits the application of BF in bamboo plastic composites. In order to improve the compatibility between PLA and BF, this study used polymerized carbodiimide (PCD) as a compatibilizer to prepare modified BF/PLA composites and investigate the effect of BF content on the composites. The results showed that the addition of PCD increased the flexural strength, flexural modulus, impact strength, tensile modulus and tensile strength of PCD-BF/PLA compared to BF/PLA composites, with the impact strength increasing the most significantly by 20.91 %. Meanwhile, the tensile strength improved by 15.06 % from 55.1 MPa to 63.4 MPa, and the flexural strength improved by 14.82 % from 80.3 MPa to 92.2 MPa. The experimental investigation of BF content revealed that when the ratio of BF to PLA was 4:6, the impact and flexural strength of the BF composites did not significantly decrease, but the flexural modulus and tensile strength increased, with the flexural modulus increasing the most significantly by 90.53 % compared to PLA, while the cost has been reduced by 13.80 %. The porosity experiment also showed that as the BF content increased, when the ratio of BF to PLA was 4:6, the porosity of the composite material was only 3.98 %, which was not further significantly increased compared to 3.62 %. The prepared high proportion biomass can be used in tableware, and other fields.