Thermally Reversible Cross-linkers To Facilitate the Improved Reprocessability of Poly(butyl methanol methacrylate) Rubber with Excellent Thermal and Mechanical Properties

This work takes advantage of the unique thermally reversible dissociation/association feature of C–ON bonds in alkoxyamine (Diol) to facilitate the reprocessability of poly(butyl methanol methacrylate) (PBMM) rubber with excellent thermal and mechanical properties. Isocyanate groups were incorporated into the PBMM backbone and then reacted with hydroxyl groups in Diol to obtain cross-linked PBMM rubber. Although its cross-linking degree is slightly lower than the conventional cross-linked rubber by an irreversible cross-linker (Dieg), it shows a higher tensile strength and elongation at break. Its decomposition temperature is about 50 °C higher than PBMM cross-linked by Dieg. Furthermore, the dissociation of C–ON bond at high temperature can break the cross-linking network of PBMM rubber to form a flowable and reprocessable melt and show an excellent ability of reshaping and healing; the association of thermally reversible C–ON bond can completely recover the cross-linking network and mechanical propertie...