Component Dynamics in Polyisoprene/Poly(4-tert-butylstyrene) Miscible Blends
Component Dynamics in Polyisoprene/Poly(4-tert-butylstyrene) Miscible Blends
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DOI：
10.1021/ma8013417
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发表时间：
2008-10
期刊：
影响因子：
5.5
通讯作者：
Quan Chen;Yumi Matsumiya;Yuichi Masubuchi;H. Watanabe;Tadashi Inoue
中科院分区：
文献类型：
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作者：
Quan Chen;Yumi Matsumiya;Yuichi Masubuchi;H. Watanabe;Tadashi Inoue
研究了顺式聚异戊二烯 (PI-20; MPI = 19.9 × 103) 和聚 (4-叔丁基苯乙烯) (PtBS-16; MPtBS = 16.4 × 103) 共混物的线性粘弹性和介电行为，其中 PtBS 浓度为 wPtBS = 30 和 50 wt%。在测试温度 T ≤ 120 °C 下，PI/PtBS 共混物处于静态均匀状态。由于 PI 具有 A 型偶极子，而 PtBS 没有，因此在低角频率 ω (<105 s−1) 下测量的共混物的介电损耗完全归因于 PI 链的整体运动。在低 T 和/或高 wPtBS 下，尽管共混物具有静态均匀性，但 PI 链的介电损耗数据不服从时间-温度叠加。粘弹性和介电数据的比较表明，在共混物中 PtBS 的松弛速度比 PI 慢。因此，PtBS 可能在 PI 全局松弛的时间尺度内提供了有效淬火的、不均匀的摩擦环境，并且这种摩擦不均匀性随 T 的变化似乎导致了失败......
Linear viscoelastic and dielectric behavior was examined for blends of cis-polyisoprene (PI-20; MPI = 19.9 × 103) and poly(4-tert-butylstyrene) (PtBS-16; MPtBS = 16.4 × 103) with the PtBS concentration of wPtBS = 30 and 50 wt %. At temperatures examined, T ≤ 120 °C, the PI/PtBS blends were in a statically homogeneous state. Since PI had the type-A dipole while PtBS did not, the dielectric loss of the blends measured at low angular frequencies ω (<105 s−1) was attributed exclusively to the global motion of PI chains. At low T and/or high wPtBS, the dielectric loss data of the PI chains did not obey the time−temperature superposition, despite the static homogeneity in the blends. Comparison of the viscoelastic and dielectric data indicated that in the blends PtBS relaxed more slowly than PI. Thus, PtBS possibly gave an effectively quenched, nonuniform frictional environment in the time scale of the global relaxation of PI, and changes of this frictional nonuniformity with T appeared to result in the failure...