Impact of PLA Poly(Lactic Acid) and PBAT Poly(butylene adipate-co-terephthalate) Coating on the Properties of Composites with High Content of Rice Husk

Composites with high content of rice husk (80% based on the solids weight) without and with PLA (5%) and PBAT (2.5%) coating were produced and characterized. Thickness, morphology, thermal and mechanical properties, water absorption capacity and hydrophilicity were evaluated. The optical microscopy indicated a more uniform surface after double coating with PLA that was confirmed by the iodine test. The modulus of elasticity and deflection were not influenced by the thin layer of PLA. On the other hand, water absorption capacity decreased with both polymers used as coating, but lower values were reached with PLA. All materials presented hydrophobic character (contact angle higher than 90 degrees) when measured instantly, with a small decreased after 5 min. The samples coated only once with PLA or PBAT showed analogous thermograms to the uncoated composite.

Automated summary

Composites with high rice husk content and coated with PLA and PBAT were evaluated for their properties. The double coating of PLA resulted in a more uniform surface, decreased water absorption, and improved hydrophilicity.