Role of graded length side chains up to 18 carbons in length on the damping behavior of polyurethane/epoxy interpenetrating polymer networks
Role of graded length side chains up to 18 carbons in length on the damping behavior of polyurethane/epoxy interpenetrating polymer networks
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DOI：
10.1016/j.eurpolymj.2013.03.024
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发表时间：
2013-06
影响因子：
6
通讯作者：
Wenwen Yu;De-zhi Zhang;M. Du;Q. Zheng
中科院分区：
文献类型：
--
作者：
Wenwen Yu;De-zhi Zhang;M. Du;Q. Zheng
以甲苯二异氰酸酯（TDI）、聚四氢呋喃二醇（PTMG）、环氧树脂（EP）、环氧丙烷（TMP）和二元醇扩链剂为原料，制备了一系列新型的聚氨酯（PU）/环氧树脂（EP）接枝侧链长度渐变的互穿聚合物网络（IPN）复合材料。研究了侧链长度、含量和基团对阻尼性能和力学性能的影响。在PU/EP IPN体系中观察到两个阻尼峰，表明低温下峰值阻尼因子（tanδ）随侧链长度的增加而增加。非极性侧链的引入略微缩小了阻尼范围。而侧链上带有极性基团则拓宽了阻尼温度范围。PU侧链的酯基与硬段的NH之间存在较强的氢键相互作用，有利于微相分离，形成较大尺寸的微相区，并在高温下出现松弛峰。从而拓宽了有效阻尼温度范围。硬段侧链含量对PU/EP IPN的低温和高温阻尼性能均有显著影响。PU/EP IPN的tanδ峰的宽度和强度随着侧链含量的增加而增加。力学性能（拉伸强度和断裂伸长率）显着影响的侧链含量。从而确立了通过控制侧链分子结构来提高弹性体机械阻尼的重要方法。
A series of novel polyurethane (PU)/epoxy resin (EP) graft interpenetrating polymer network (IPN) composites with graded length side chains were prepared from toluene diisocyanate (TDI), polytetrahydrofuran glycol (PTMG), EP, trimethylolpropane (TMP), and diol chain extenders. The effects of the side chain lengths, content, and groups on the damping properties and mechanical properties were investigated. Two damping peaks were observed in the PU/EP IPN system, indicating that the peak damping factor (tanδ) increased with increased side chain length at low temperatures. The introduction of an apolar side chain slightly narrowed the damping range. However, the side chain carrying polar groups broadened the damping temperature range. The strong H-bond interaction between the ester group of side chain and the NH of hard segments in PU was believed to favor microphase separation to form a larger-sized domain and induce the appearance of the relaxation peak at high temperatures. Consequently, the effective damping temperature range was broadened. The side chain content tethered in the hard segment remarkably influenced the damping properties of PU/EP IPNs both at low and high temperatures. The width and intensity of the tanδ peaks of PU/EP IPNs increased with increased side chain content. The mechanical properties (tensile strength and elongation at break) were significantly affected by the side chain content. Thus, an important method of improving the mechanical damping of elastomers by controlling the side chain molecular structure was established.