(Bio)degradable Biochar Composites of PLA/P(3HB-<i>co</i>-4HB) Commercial Blend for Sustainable Future—Study on Degradation and Electrostatic Properties

Abstract

Interesting alternatives to expensive biodegradable polymers are their composites with natural fillers. The addition of biochar to a blend of poly(lactic acid) (PLA) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) was studied, and the resulting materials were evaluated for their properties and changes during degradation. Introducing biochar as a filler brought a noticeable improvement in electrostatic properties. Surface resistivity decreased from 3.80 × 1012 for the sample without biochar to 1.32 × 1012 for the sample with 30% filler content. Degradation tests revealed distinct differences in the degradation profile for composites due to the presence of filler. Composites with a lower biochar content displayed curling crack edges during hydrolytic degradation, and when the filler content reached 20 wt%, PLA loss accelerated. This study suggests that biochar-based composites have potential to be used as sustainable materials with improved properties.

Keywords

• biodegradable composites
• PLA
• P(3HB-<i>co</i>-4HB)
• biochar
• electrostatic properties
• composting