Hydrothermal Hot Pressing of CaCO₃‐Chitosan Composites with High CaCO₃ Content

Abstract

In this study, a hydrothermal hot pressing (HHP) method was used for the preparation of molded composites with high CaCO3 content. Specifically, composites consisting of chemically synthesized CaCO3 and chitosan and scallop shells milled with a ball mill were molded by the HHP method; the structures, mechanical properties, and vibration absorption characteristics of the resulting disc-shaped molded composites were investigated. All the composites had high CaCO3 contents (93%); flexural strengths (several megapascals) comparable to those of limestone and cement; and vibration absorption characteristics (logarithmic attenuation factors of 0.07–0.18) superior to those of aluminum alloys, stainless steel, and ceramics (which have logarithmic attenuation factors of <0.01). The composites prepared from the CaCO3-chitosan composites can be expected to find application as light-control materials, as materials for controlling the propagation of light, sound, and vibration waves including vibration-isolating materials and as CO2-fixation materials.