Multi-recyclable Shape Memory Supramolecular Polyurea with Long Cycle Life and Superior Stability

Shape memory polymers (SMPs) have attracted a wide range of interest owing to their technological impact. It remains a great challenge to construct SMPs with both excellent shape memory recoverability and durability and satisfactory reprocessability. Herein, by incorporating low-content noncovalently bonded linkers into the covalent network of SMP, a shape memory supramolecular polyurea (SMSP) with excellent reprocessability and shape memory properties has been successfully constructed. The SMSP was endowed with remarkable shape memory performance and solvent resistance owing to its covalent cross-linking. It displayed outstanding shape memory cycle stability with above 92.7% of shape recovery ratio even after 20 consecutive shape memory cycles. In addition, SMSP could be recycled for 7 times without clear decline in mechanical properties, exhibiting excellent multiple reprocessability. It is anticipated that this work will provide a new insight into designing SMPs with excellent reprocessability and cycle stability.