Effect of Different Natural Fibers on Mechanical and Disintegration Properties of Compostable Biobased Plastics

This study evaluates the economic and degradation properties of natural fiber-reinforced PHBH (Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)). Compounds containing the compostable biobased plastic PHBH and 30 mass% of cotton, merino wool, wood fibers, and hemp fibers were produced, and 0.4 mm thick foils were manufactured using a laboratory hot press. Samples for mechanical characterization were produced by injection molding and were buried in bioactive soil for 16 weeks to determine the influence of fiber type on the disintegration speed in soil. The disintegration was measured by subsequent excavation, determination of dry mass loss and visual inspection. All kinds of natural fibers generally improve disintegration speed. The most significant improvement was reached by samples containing cotton and wool, respectively, which experienced similar mass loss, followed by the ones containing hemp fibers. The smallest increase in disintegration speed was achieved by samples containing wood fibers. Mechanical properties and cost-saving potential increased in the cotton and hemp samples.