Centre for Education and Research on Macromolecules (CERM), University of Liege (ULg), Building B6a, 4000 Liège, Belgium.
Macromol Rapid Commun. 2011 Aug 17;32(16):1264-9. doi: 10.1002/marc.201100250. Epub 2011 Jun 20.
A new concept to build shape memory polymers (SMP) combining outstanding fixity and recovery ratios (both above 99% after only one training cycle) typical of chemically crosslinked SMPs with reprocessability restricted to physically crosslinked SMPs is demonstrated by covalently bonding, through thermoreversible Diels-Alder (DA) adducts, star-shaped poly(ε-caprolactones) (PCL) end-functionalized by furan and maleimide moieties. A PCL network is easily prepared by melt-blending complementary end-functional star polymers in retro DA regime, then by curing at lower temperature to favour the DA cycloaddition. Such covalent network can be reprocessed when heated again at the retro DA temperature. The resulting SMP shows still excellent shape memory properties attesting for its good recyclability.
通过热可逆 Diels-Alder（DA）加合物共价键合，将呋喃和马来酰亚胺官能团末端官能化的星形聚（ε-己内酯）（PCL），展示了一种将交联化学 SMP 的出色固定和恢复比率（仅经过一个训练循环后均超过 99%）与限制在物理交联 SMP 的可再加工性相结合的新概念。在 retro DA 条件下熔融共混互补端官能团星形聚合物，然后在较低温度下固化以促进 DA 环加成，很容易制备 PCL 网络。当再次在 retro DA 温度下加热时，这种共价网络可以进行再加工。所得 SMP 仍表现出优异的形状记忆性能，证明其具有良好的可回收性。
