Mechanical, thermal and acoustical characterizations of an insulating bio-based composite made from sunflower stalks particles and chitosan

•An insulating bio-based composite was made with chitosan and sunflower's stalks particles.•Its thermal, mechanical and acoustical properties were determined.•Its mechanical and thermal performances are competitive with those of other insulating bio-based materials.

This study has for objective the determination of thermal, mechanical and acoustical properties of insulating bio-based composite made with chitosan and sunflower's stalks particles. An experimental design was established to find the size grading of particles, the ratio chitosan/sunflower particles and the stress of compaction influencing the thermal and mechanical properties. Composites with a thermal conductivity (κ) of 0.056 W m−1 K−1, a maximum stress (σmax) of 2 MPa and an acoustic coefficient of absorption (α) of 0.2 were obtained with a ratio of chitosan of 4.3% (w/w) and a size grading of particles higher to 3 mm. These mechanical and thermal performances are competitive with those of other insulating bio-based materials available on the market.