Utilization of corn cob, an essential agricultural residue difficult to disposal: Composite board manufactured improved thermal performance using microencapsulated PCM

Abstract

Among agricultural residues, corn cob (CC) is an essential residue of corn. Unlike common agricultural residues, CC is nutrient-dense and difficult to recycle as fertilizer or feed. Its fiber composition is similar to that of wood, allowing it to act as a wood substitute. In this study, we evaluated the usability of CC in buildings by preparing a composite board composed of CC powder and microencapsulated phase-change material (MPCM). The fibrous and porous sponge structures of CC were confirmed using field-emission scanning electron microscopy (FE-SEM). The sponge structure can be impregnated with MPCM, as confirmed by the SEM image of the CCB (corn-cob composite board with MPCM). In addition, contact angle measurements confirmed the adhesiveness of the composite board, where CCB50 showed the best adhesive strength. To determine the effect of the MPCM on the composite, the thermal performance was evaluated using differential scanning calorimetry (DSC) and dynamic thermal analysis. The DSC analysis confirmed that CCB50 had a latent heat of 20.11 J/g at a melting point of 27.8 °C, and the thermal performance was greatly improved. The temperature behavior of the specimen was investigated by heating and cooling using a heating film. During the heating process, the thermal storage effect was apparent in the temperature data of CCB25 and CCB50, and a time-delay effect was observed during the cooling process; these phenomena were clearly visible in the thermal image and were caused by the thermal preservation of the MPCM. CCB is a composite manufactured from biomaterials and can be used as a building material with high thermal performance.