Preparation and properties of Diels-Alder reactive thermal-heating lignin/EPDM rubber

In order to improve the environmental pollution of rubber materials after disposal, Diels-Alder reactive thermal-heating EPDM rubber (CEF-Lig) was prepared using furfural-modified lignin (F-Lig) as a filler in the solid phase blending method. The high-temperature melt processing and low-temperature cross-linking molding of CEF-Lig composites were endowed by the fracture and reconstruction of reversible cross-linking networks, and the effects of F-Lig content on the microstructure, mechanical properties, and thermal repair properties of CEF-Lig materials were explored. The results demonstrate that the CEF-Lig composites with thermally repairable recyclable properties are successfully prepared. With the increase of F-Lig content, the tensile strength shows the trend of increasing and then decreasing, and the tensile strength of CEF-Lig7 reaches the maximum value of 4.6 MPa, which is 4.6 times of that of the control group (CEPDM) without F-Lig. The F-Lig increases the thermal decomposition temperature of the CEF-Lig, and the temperature corresponding to the maximum decomposition rate (T_max) of CEF-Lig9 was increased by 8.8 ℃ compared to CEPDM. The CEF-Lig has a good thermal repair ability, the mechanical strength of the primary repair efficiency are more than 70%, and the secondary repair efficiency are more than 60%. In addition, the solid phase blending method is adopted to effectively avoid solvent contamination and improve the production efficiency, which provides a reference for the preparation of other reversible cross-linked polymers.