Curing behavior of epoxy resin with acetal structure and preparation and properties ofits carbon fiber composites

To investigate the forming process of bio-based epoxy resin system with acetal structure, the rheological properties and curing behavior of the epoxy resin system with acetal structure were studied by rotating rheometer and non-isothermal DSC. The glue injecting temperature is determined to be about 40℃. The curing kinetic parameters were obtained by the piecewise model combining the autocatalytic model and the n-order model. The fitting curves from the piecewise model are in good agreement with the experimental curves, indicating that the model can accurately describe the curing reaction process of epoxy resin system with acetal structure at the heating rates of 2.5-20 K/min. The curing procedure of the resin system was determined by an extrapolation method. The tensile strength and bending strength of the epoxy resin with acetal structure are 79 MPa and 130 MPa, respectively. It is found that the interfacial shear strength (IFSS) and interlaminar shear strength (ILSS) of carbon fiber/acetal epoxy resin composites are similar to those of carbon fiber/commercial epoxy resin composites, indicating that the interfacial bonding property between acetal epoxy resin and carbon fiber is similar to that of commercial epoxy resin. In addition, the tensile and flexural properties of the two composites are similar, indicating that the degradable acetal epoxy resin may replace the commercial epoxy resin and give potential competitive advantages over the applications. In addition, the carbon fiber/acetal epoxy resin composites have good degradation performance, and the single fiber tensile strength of the recovered carbon fiber is comparable to that of the original carbon fiber, indicating that high-quality carbon fiber can be effectively recycled.