Wang Kaojin, Jia Yong-Guang, Zhu X X
Département de Chimie, Université de Montréal, C.P. 6128, Succ. Centre-ville, Montréal, Quebec H3C 3J7, Canada.
ACS Biomater Sci Eng. 2015 Sep 14;1(9):855-863. doi: 10.1021/acsbiomaterials.5b00226. Epub 2015 Aug 7.
For the design of shape memory polymers with potential biomedical applications, we synthesized methacrylate-based monomers bearing biological compounds such as cholic acid and cinnamic acid in addition to oligo(ethylene glycol) as pendant groups and opted to use a simple radical polymerization method for the preparation of the copolymers. The glass transition temperatures of these polymers are broad and tunable and can thus accommodate dual and triple shape memory behaviors. The fixity ratios of dual and triple shape memory are all above 91%. The recovery ratio of dual shape memory is 89.5%, whereas the two recovery ratios of triple shape memory are 53.2 and 81.5%, respectively. To further improve the shape memory properties, a cinnamic acid-based methacrylate monomer was incorporated into the copolymers to enable a photo-cross-linking of the terpolymer. After irradiation, the fixity ratios remain high, whereas the recovery ratios of dual and triple shape memories are much improved. The terpolymers after light irradiation even show quadruple shape memory property. Different irradiation times were tested to optimize the shape memory effects. The recovery ratio of dual shape memory of such terpolymers can reach as high as 98.6%, whereas the recovery ratios of triple and quadruple shape memories are improved to the range of 75.3-99.1%.
为了设计具有潜在生物医学应用的形状记忆聚合物，我们合成了基于甲基丙烯酸酯的单体，这些单体除了带有作为侧基的低聚乙二醇外，还含有诸如胆酸和肉桂酸等生物化合物，并选择使用简单的自由基聚合法来制备共聚物。这些聚合物的玻璃化转变温度范围较宽且可调节，因此能够呈现双重和三重形状记忆行为。双重和三重形状记忆的固定率均高于91%。双重形状记忆的回复率为89.5%，而三重形状记忆的两个回复率分别为53.2%和81.5%。为了进一步改善形状记忆性能，将一种基于肉桂酸的甲基丙烯酸酯单体引入共聚物中，以使三元共聚物能够进行光交联。辐照后，固定率仍然很高，而双重和三重形状记忆的回复率有了很大提高。光辐照后的三元共聚物甚至呈现四重形状记忆性能。测试了不同的辐照时间以优化形状记忆效果。此类三元共聚物的双重形状记忆回复率可高达98.6%，而三重和四重形状记忆的回复率提高到75.3 - 99.1%的范围。
