Experimental Test for Viscoelastic Relaxation of Polyisoprene Undergoing Monofunctional Head-to-Head Association and Dissociation
Experimental Test for Viscoelastic Relaxation of Polyisoprene Undergoing Monofunctional Head-to-Head Association and Dissociation
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DOI：
10.1021/acs.macromol.6b01313
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发表时间：
2016-09
期刊：
影响因子：
5.5
通讯作者：
Yumi Matsumiya;H. Watanabe;O. Urakawa;Tadashi Inoue
中科院分区：
文献类型：
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作者：
Yumi Matsumiya;H. Watanabe;O. Urakawa;Tadashi Inoue
对分子量为30.5 × 103的端羧基聚异戊二烯（PI-COOH）进行了粘弹实验，该聚异戊二烯通过端羧基间的氢键作用发生链间缔合和解离。作为参考，还对纯PI单聚体（链端无COOH基团）和PI 2二聚体（M = 61.0 × 103）进行了检测，后者通过PI-阴离子（PI-COOH样品的前体）的末端偶联合成。将PI-COOH、纯单聚体和二聚体样品在低聚丁二烯（oB）中稀释至10重量%的浓度。纯的单聚体和二聚体在该浓度下表现出非缠结的劳斯行为，正如从其分子量所预期的那样。在低温下（T ≤ 0 °C），PI-COOH样品的弛豫比参比单聚体慢，但比二聚体快，而PI-COOH的弛豫随T > 0 °C的增加而接近单聚体的弛豫，PI-COOH弛豫时间的变化与角频率的变化有关。
A viscoelastic test was made for end-carboxylated polyisoprene (PI-COOH) of the molecular weight M = 30.5 × 103 that underwent the interchain association and dissociation through hydrogen bonding of the COOH groups at the chain end. As a reference, the test was made also for neat PI unimer (with no COOH group at the chain end) and for PI2 dimer (with M = 61.0 × 103), the latter being synthesized through end-coupling of PI– anions (precursor of the PI-COOH sample). The PI-COOH, neat unimer, and dimer samples were diluted in oligomeric butadiene (oB) to a concentration of 10 wt %. The neat unimer and dimer exhibited nonentangled Rouse behavior at this concentration, as expected from their molecular weights. At low temperatures (T ≤ 0 °C) the PI-COOH sample relaxed slower than the reference unimer but faster than the dimer, whereas the relaxation of PI-COOH approached that of the unimer with increasing T > 0 °C, and this change of the relaxation time of PI-COOH was associated with changes in the angular freq...