Nair Devatha P, Cramer Neil B, Scott Timothy F, Bowman Christopher N, Shandas Robin
Department of Mechanical Engineering, University of Colorado, Boulder CO, USA.
Polymer (Guildf). 2010 Sep 3;51(19):4383-4389. doi: 10.1016/j.polymer.2010.07.027.
In this study we introduce the use of thiol-ene photopolymers as shape memory polymer systems. The thiol-ene polymer networks are compared to a commonly utilized acrylic shape memory polymer and shown to have significantly improved properties for two different thiol-ene based polymer formulations. Using thermomechanical and mechanical analysis, we demonstrate that thiol-ene based shape memory polymer systems have comparable thermomechanical properties while also exhibiting a number of advantageous properties due to the thiol-ene polymerization mechanism which results in the formation of a homogenous polymer network with low shrinkage stress and negligible oxygen inhibition. The resulting thiol-ene shape memory polymer systems are tough and flexible as compared to the acrylic counterparts. The polymers evaluated in this study were engineered to have a glass transition temperature between 30 and 40 °C, exhibited free strain recovery of greater than 96% and constrained stress recovery of 100%. The thiol-ene polymers exhibited excellent shape fixity and a rapid and distinct shape memory actuation response.
在本研究中，我们介绍了硫醇-烯光聚合物作为形状记忆聚合物体系的应用。将硫醇-烯聚合物网络与一种常用的丙烯酸类形状记忆聚合物进行了比较，结果表明，对于两种不同的硫醇-烯基聚合物配方，其性能有显著改善。通过热机械和力学分析，我们证明硫醇-烯基形状记忆聚合物体系具有可比的热机械性能，同时由于硫醇-烯聚合机理，还表现出许多有利性能，该机理导致形成具有低收缩应力和可忽略不计的氧抑制作用的均匀聚合物网络。与丙烯酸类对应物相比，所得的硫醇-烯形状记忆聚合物体系坚韧且柔韧。本研究中评估的聚合物被设计成玻璃化转变温度在30至40°C之间，表现出大于96%的自由应变恢复率和100%的约束应力恢复率。硫醇-烯聚合物表现出优异的形状固定性以及快速且明显的形状记忆驱动响应。
