论文标题
通过将二聚体聚合物混合物固定来朝着理想的玻璃过渡
Towards the ideal glass transition by pinning in a dimer-polymer mixture
论文作者
论文摘要
我们使用聚合物及其二聚体的混合物以\ emph {pinning}启发的方式控制动力学。在我们的$α$ - 甲基苯乙烯的系统中，聚合物在比二聚体更高的温度下的玻璃转变，在中等温度下，聚合物可作用于“销钉”二聚体。在此温度范围内，我们使用差分扫描量热法来推断一个点对点的长度，我们发现它受到固定程度的深刻影响。我们通过介电光谱确定了系统的动力学，发现“固定”的动力学大大减慢了，但相对于我们测量的精度，脆弱性仅显示出很小的变化。这可能表明在我们使用的方法中，脆弱性对诸如点对点长度之类的数量的依赖性相对较弱。 ％的％比人们预期的是，另一种解释是，二聚体可以作用于\ emph {塑料}聚合物，从而开放了放松的路线，这对于完全固定的系统可能无法访问。
We use a mixture of a polymer and its dimer to control dynamics in a manner inspired by \emph{pinning} a fraction of the system. In our system of $α$-methyl styrene, where the polymer has a glass transition at higher temperature than the dimer, at intermediate temperatures, the polymer acts to "pin" the dimer. Within this temperature range, we use differential scanning calorimetry to infer a point-to-set length which we find to be profoundly influenced by the degree of pinning. We determine the dynamics of the system with dielectric spectroscopy and find that while the dynamics are very substantially slowed by the "pinning", the fragility exhibits only a small change relative to the precision of our measurements. This may indicate that in the approach we have used, fragility has a relatively weak dependence on quantities such as the point--to--set length. % than one might expect, However, an alternative explanation is that the dimer may act to \emph{plasticize} the polymer and thus open routes to relaxation that may be inaccessible to fully pinned systems.
