Low output in stress and energy in rubbery state has been a bottleneck for wide-spread applications of thermoset shape memory polymers (SMPs). Traditionally, stress or energy storage in thermoset network is through entropy reduction by mechanical deformation or programming. We here report another mechanism for energy storage, which stores energy primarily through enthalpy increase by stretched bonds during programming. As compared to entropy-driven counterparts, which usually have a stable recovery stress from tenths to several MPa and energy output of several tenths MJ/m3, our rubbery network achieved a recovery stress of 17.0 MPa and energy output of 2.12 MJ/m3 in bulk form. The giant stress and energy release in the rubbery state will enhance applications of thermoset SMPs in engineering structures and devices.
展开▼
机译:橡胶态应力和能量的低输出一直是热固性形状记忆聚合物(SMP)广泛应用的瓶颈。传统上,热固性网络中的应力或能量存储是通过机械变形或编程来减少熵。我们在这里报告了另一种能量存储机制,该机制主要通过在编程过程中通过拉伸键的焓增加来存储能量。与通常在十分之一到几MPa范围内具有稳定恢复应力且能量输出只有十分之几MJ / m 3 sup>的熵驱动的对应物相比,我们的橡胶网络实现了17.0 MPa的恢复应力和能量批量输出2.12 MJ / m 3 sup>。橡胶态的巨大应力和能量释放将增强热固性SMP在工程结构和设备中的应用。
展开▼