Semi-dry technology-mediated coir fiber and Scots pine particle-reinforced sustainable cementitious composite panels

Abstract

The demand for natural fiber-reinforced sustainable products is increasing continuously worldwide. The technology to produce lignocellulosic fiber-reinforced cementitious materials is currently limited; hence, new routes for composite development are being explored. The current study presents an innovative semi-dry technology implemented on lignocellulosic material (coir fiber and Scots pine particle) reinforced composite panels. Composite panels of 12 mm thickness and 1200 kg/m3 nominal densities were prepared from lignocellulosic materials and OPC (Ordinary Portland cement). Measurements determined the dimensions of the lignocellulosic materials to be the following: coir fibers were within 0.1 to 1.25 mm in length while Scots pine particles ranged from 0.355 to 1.6 mm in length. The lignocellulosic materials were loaded in different proportions (100% Scots pine, 60% Scots pine/40% coir, 50% Scots pine/50% coir, 40% Scots pine/60% coir, and 100% coir) to produce five composite panels. The proportions of water glass additive and OPC remained constant. A cheaper and more convenient novel fabrication approach (semi-dry technology) was utilized to produce the composite panels via pressing implementation (3.2 to 7.1 MPa). Finally, the thermal, physical, morphological, and mechanical properties of all the composite panels were tested. The experimental results were significant and could facilitate composite manufacturers with potential and sustainable products possessing superior performance characteristics. The most promising finding of this research is the increased thermal and mechanical properties of the composites along with significant dimensional stability against moisture with the increase in loading of coir fibers in the matrix system. The SEM (scanning electron microscopy) and SEM-mediated EDX (energy-dispersive X-ray spectroscopy) also provided the morphological and elemental analysis of the fibers, cements, and associated composites. The FTIR (Fourier transform infrared spectroscopy) study also further confirmed the successful reinforcement of the lignocellulosic materials and OPC. Moreover, the perceived thermal conductivity of the composite materials also indicates promising routes toward the development of insulation materials using renewable lignocellulosic materials.