Core-shell nano-latex blending method to prepare multi-shape memory polymers
Core-shell nano-latex blending method to prepare multi-shape memory polymers
复制标题
核壳纳米乳胶共混法制备多形状记忆聚合物
DOI：
10.1039/c7sm00899f
复制
发表时间：
2017-08-21
期刊：
影响因子：
3.4
通讯作者：
Gao, Xiang
中科院分区：
文献类型：
--
作者：
Li, Hongze;Luo, Yingwu;Gao, Xiang
通过共混一系列苯乙烯（St）-（苯乙烯无规-甲基丙烯酸酯（MA））-嵌段-苯乙烯三嵌段共聚物纳米乳液，制备了多种形状记忆聚合物。使用可逆加成-断裂链转移（RAFT）乳液聚合方法合成的这些胶乳具有核-壳结构。核由中间的聚（St-无规-MA）嵌段形成。它们通过调节St/MA比充当具有可变转变温度的过渡相。当胶乳与相同的PSt壳但不同的聚（St-random-MA）核共混时，壳起到防止这些聚（St-random-MA）核在热压处理后形成交联网络的聚集的作用。因此，获得了具有均匀分布的多个纳米相的聚合物，其显示出四重形状记忆行为。此外，通过改变不同胶乳的共混比例，可以有目的地提高相应过渡相的质量比，从而改善材料在一定温度下的形状记忆和回复性能。得到了在所有转变温度下形状记忆和回复率均大于80%的优化的多重形状记忆聚合物。
Multi-shape memory polymers were prepared by blending a series of styrene (St)-block-(styrenerandom- meth acrylate (MA))-block-styrene triblock copolymer nano-latexes. These latexes synthesized using a reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization method have a core-shell structure. The cores are formed by the middle poly(St-random-MA) blocks. They act as transition phases with variable transition temperatures via adjusting the St/MA ratio. When the latexes are blended with an identical PSt shell but different poly(St-random-MA) cores, the shells play a role in preventing the aggregation of these poly(St-random-MA) cores forming a crosslinked network after hot-press treatment. Therefore a polymer with well-distributed multiple nanophases is achieved, which shows a quadruple-shape memory behavior. Furthermore, the shape memory and recovery performance at a certain temperature can be improved on purpose by increasing the mass ratio of the corresponding transition phases, which can be realized via simply varying the blending ratio of different latexes. An optimized multi-shape memory polymer with the shape memory and recovery ratio higher than 80% at all the transition temperatures is achieved.