Novel low temperature processing techniques for apatite ceramics and chitosan polymer composite bulk materials and its mechanical properties

摘要

A co-precipitation method was used for processing chitosan (CHI)/calcium hydrogen phosphate dehydrate (DCPD) hybrid material. CHI solution was mixed into 1.0-M calcium nitrate solution. CHI/DCPD hybrid material was prepared by the above explained addition of CHI and Ca ion source to 1.0-M diammo-nium hydrogen phosphate solution. It was observed by transmission electron microscopy that CHI and DCPD were mixed within submicron meter scale. CHI/HA bulk materials derived from the CHI/DCPD hybrid materials were obtained by using a hydrothermal hot-pressing (HHP) method. A pressure of 40MPa was initially applied to the sample. An HHP autoclave was heated up to 150℃ for 2h. Modified 3-point bending tests were conducted to obtain an easy estimate of the fracture toughness for the CHI/HA bulk materials made with the HHP method. The critical stress intensity factor K_c of the fabricated CHI/HA bulk materials was enhanced from 0.30 to 0.40 MPam~(1/2) by the hybridization of CHI into DCPD.