The influence of additives on polymer matrix mobility and the glass transition
The influence of additives on polymer matrix mobility and the glass transition
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DOI：
10.1039/d0sm01634a
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发表时间：
2021-01-14
期刊：
影响因子：
3.4
通讯作者：
Lipson, Jane E. G.
中科院分区：
文献类型：
--
作者：
DeFelice, Jeffrey;Lipson, Jane E. G.
在界面附近的区域中，玻璃形成液体的微观性质可能从其平衡体积值受到扰动。在这项工作中，我们探讨了分散在基体中的添加剂颗粒的界面效应如何影响材料的局部流动性及其玻璃化转变温度T-g。实验测量和模拟结果表明，添加剂，如纳米颗粒、气体分子和低聚物，可以改变周围聚合物基质的迁移率和T-g（即使对于相对小浓度的添加剂;例如，5- 10体积%），从而导致T-g增强或抑制。因此，添加剂为改变聚合物材料的性质而不显著改变其化学组成提供了潜在途径。在这里，我们应用有限迁移率（LM）模型来模拟一个矩阵包含添加剂物种。我们发现，添加剂的浓度，以及其非常局部的影响周围的基质材料的强度，将决定是否系统的Tg升高或降低，相对于纯基质。我们表明，将添加剂纳入简单的LM模拟方法，成功地描述了散装和薄膜玻璃态固体的行为，导致直接连接与广泛的聚合物/添加剂系统的实验和模拟结果。
In the region near an interface, the microscopic properties of a glass forming liquid may be perturbed from their equilibrium bulk values. In this work, we probe how the interfacial effects of additive particles dispersed in a matrix can influence the local mobility of the material and its glass transition temperature, T-g. Experimental measurements and simulation results indicate that additives, such as nanoparticles, gas molecules, and oligomers, can shift the mobility and T-g of a surrounding polymer matrix (even for relatively small concentrations of additive; e.g., 5-10% by volume) relative to the pure bulk matrix, thus leading to T-g enhancement or suppression. Additives thus provide a potential route for modifying the properties of a polymer material without significantly changing its chemical composition. Here we apply the Limited Mobility (LM) model to simulate a matrix containing additive species. We show that both additive concentration, as well as the strength of its very local influence on the surrounding matrix material, will determine whether the T-g of the system is raised or lowered, relative to the pure matrix. We demonstrate that incorporation of additives into the simple LM simulation method, which has successfully described the behavior of bulk and thin film glassy solids, leads to direct connections with available experimental and simulation results for a broad range of polymer/additive systems.