Influence of fiber modifications on PLA/fiber composites. Behavior to accelerated weathering

Cellulose fibers obtained by organosolv process were used in preparing PLA/fiber composites. In an attempt to improve the adhesion between the fibers and the polymer matrix, the cellulose fibers were treated chemically using stearoyl chloride as well as enzymatically by laccase. The addition of the cellulose fibers to the PLA matrix had a positive effect on some of the mechanical properties of the composites, while some properties were compromised. In addition, the thermal properties were improved, while the rheological properties were decreased. Generally, the fiber modifications did not have the desired effect of improving the mechanical properties further, while for the thermal properties, there was a significant difference when chemically modified fibers were used. Accelerated weathering generally led to the deterioration of the composites properties. However, some properties were better preserved with the inclusion of modified fibers into the PLA matrix, especially with the enzymatically modified fibers.