Mineral Microparticles and Wood Flour as Fillers of Different Biocomposites

In this work, authors attempted to present and compare test results of two different injection molded biopolymers: thermoplastic wheat starch and cellulose blend as matrices for biocomposites. They were filled with commonly available wood flour or tuff microparticles as an alternative to cellulose-based natural fibres. Physical, mechanical, processing and surface properties of biocomposites were tested, as well as degradation in water or physiological saline and its influence on tensile properties. Also, the tensile fracture surfaces were studied using scanning electron microscope. There was different influence of wood flour and tuff on each biopolymer. The fillers gave stiffness improvement of all biocomposites compared to neat biopolymers and the effect was stronger for tuff powder. Moreover, tuff addition caused hardness increase and reduction of water uptake. While tuff may be considered as stabilizer, reinforcement and even fertilizer for biodegradable products, wood flour advantages are: common availability, stiffness increase effect and possibility of controlling composite degradation time.