SUMITOMO Rubber Industries, LTD, 1-1, 2-chome, Tsutsui-cho, Chuo-ku, Kobe 651-0071, Japan.
Soft Matter. 2017 Nov 8;13(43):7862-7869. doi: 10.1039/c7sm01262d.
We studied the dynamics of zinc diacrylate (ZDA) reinforced polybutadiene rubber (BR) (ZDA/BR) using the quasielastic neutron scattering technique to determine the effect of concentration of ZDA on polymer dynamics. First, we evaluated the temperature dependence of mean square displacements (〈u〉) for ZDA/BR with different ZDA volume fractions. 〈u〉 increased with temperature below 170 K, and we observed no significant ZDA volume fraction dependence. However, it increased more steeply above 170 K, and the value of 〈u〉 was smaller for the samples with increasing ZDA fraction. To elucidate the origin of the decrease in 〈u〉 with increasing ZDA content, dynamic scattering laws (S(Q,ω)) were analyzed. An increase in the elastic component, an increase in the mean relaxation time, and a broadening of distribution of relaxation time were observed with the increasing volume fraction of ZDA. In addition, the ZDA volume fraction dependence of the elastic component roughly corresponded to that of elastic modulus, indicating that the elastic component is related to its mechanical strength. Referring to the previously reported static structure of the present ZDA/BR system, a model for the heterogeneous BR dynamics was proposed. This model assumes the coexistence of immobile, mobile, and interfacial constrained mobile regions. It was found to be appropriate for the explanation of the observed dynamics. We proposed that a network-like structure of the BR having a high crosslinking density around ZDA aggregates is mainly responsible for the high elastic modulus of ZDA/BR.
我们使用准弹性中子散射技术研究了锌二丙烯酸酯（ZDA）增强聚丁二烯橡胶（BR）（ZDA/BR）的动力学，以确定 ZDA 浓度对聚合物动力学的影响。首先，我们评估了具有不同 ZDA 体积分数的 ZDA/BR 的均方位移（〈u〉）随温度的变化。〈u〉在 170 K 以下随温度升高而升高，且我们未观察到 ZDA 体积分数的显著依赖性。然而，在 170 K 以上，〈u〉的增加更为陡峭，且随着 ZDA 分数的增加，〈u〉的值更小。为了解释随着 ZDA 含量增加而导致〈u〉降低的原因，我们分析了动态散射律（S（Q，ω））。随着 ZDA 体积分数的增加，观察到弹性分量增加、平均松弛时间增加和松弛时间分布变宽。此外，弹性分量的 ZDA 体积分数依赖性大致对应于弹性模量的依赖性，表明弹性分量与其机械强度有关。参考先前报道的本 ZDA/BR 系统的静态结构，提出了一种不均匀 BR 动力学模型。该模型假设存在非活动、移动和界面约束移动区域共存。发现该模型适用于对观察到的动力学的解释。我们提出，在 ZDA 聚集物周围具有高交联密度的 BR 的网络状结构是 ZDA/BR 具有高弹性模量的主要原因。
