Effect of jute fibers on morphological characteristics and properties of thermoplastic starch/biodegradable polyester blend

The current work aims to study the effect of jute fiber (JF) on the characteristics and performance of a thermoplastic starch/poly(lactic acid)/poly(butylene adipate-co-terephthalate) (TPS/PLA/PBAT) blend. TPS/PLA/PBAT/JF composites with a constant TPS:PLA:PBAT weight ratio of 60:30:10 and 5, 10, and 15 wt% additions of JF were fabricated using an extruder. The obtained green composites were then molded into test specimens using an injection molding machine. The TPS/PLA/PBAT/JF composites exhibited higher Young's modulus and storage modulus but lower elongation at break and impact strength than the TPS/PLA/PBAT blend. The Young's modulus and storage modulus of the composites significantly increased with increasing JF concentration. The crystallinity of PLA in the blend also increased with the addition of JF, while its T-g, T-cc, and T-m decreased. SEM confirmed a co-continuous phase structure of both TPS/PLA/PBAT blend and TPS/PLA/PBAT/JF composites; however, the phase size of each polymer decreased with the addition of JF. JF plays roles as a reinforcing agent, nucleating agent for PLA, and compatibility promoter between the TPS and PLA/PBAT phases. Although JF reduced thermal expansion, it retarded the biodegradation of the blend. The obtained green TPS/PLA/PBAT/JF composites have great potential as materials for biodegradable and environmentally benign injection-molded products.

Automated summary

The study demonstrates that the addition of jute fiber can improve the modulus of the starch/poly(lactic acid)/poly(butylene adipate-co-terephthalate) blend, but decrease its elongation at break and impact strength. With increasing jute fiber concentration, the modulus of the composites significantly increases, while the crystallinity of PLA also increases and the thermal properties change.