Preliminary Optimization of Composite Compositions Based on Modified Sosnowsky’s Heracleum

Abstract

Composite materials based on modified stems of Heracleum sosnowskyi (Sosnowsky's hogweed) and polyurethane binder are used for thermal insulation of building structures. The purpose of this study was to create a mathematical model for the optimization of composite compositions and the prediction of their properties. Numerical methods of mathematical statistics were used and nomogram plots were obtained. It was possible to select optimal compositions for the given characteristics of composites based on modified stems of H. sosnowskyi and polyurethane binder and predict the thermophysical properties of composites by knowing their composition. To produce thermal insulation boards with a thermal conductivity coefficient of 0.05 W/(m°C) it was necessary to use particles of H. sosnowskyi with a size of approximately 5 mm. The ratio of plant raw material and polyurethane binder was approximately 3:1 by weight. The bending strength of the thermal insulation boards was 1.56 MPa, and the compressive strength was 0.27 MPa.