Lightweight composite materials made of paper sludge and corn starch

Abstract

Novel composite materials have been prepared by primary paper sludge (PS) and biopolymer (modified corn starch (MCS). The MCS is used as a binder. The aim of the research was to investigate the properties, microstructure and durability (water erosion) of composite materials (CM). The CM were formed from 100 wt% of paper sludge and 20 wt% of various concentrations (2.5%, 5.0% and 7.5%) of MCS were added. Corn starch was heated 3 h at 150 °C temperature. The CM produced had a bulk density of 0.89–1.18 g/cm3, compressive strength at 10% relative deformation 4.8–9.3 MPa, thermal conductivity 0.092–0.132 W/m·K. Additionally, this study underscores that the CM show good durability (resistance to water erosion) and hygrothermal qualities. In fact, the MSC solution incorporated in the paper sludge showed improved physical-mechanical properties and durability of the CM. The research shows that CM can be formed from paper sludge and MCS, and these can be used as indoor masonry units because they also have good mechanical, hydroscopic and thermal insulation properties.