Lorthioir Cédric, Alegría Angel, Colmenero Juan
Departamento de Física de Materiales, Universidad del País Vasco (UPV/EHU), Facultad de Química, Apartado 1072, 20080 San Sebastián, Spain.
Phys Rev E Stat Nonlin Soft Matter Phys. 2003 Sep;68(3 Pt 1):031805. doi: 10.1103/PhysRevE.68.031805. Epub 2003 Sep 24.
The local dynamics of the low-T(g) component in a polymer blend, dynamically asymmetric poly(styrene)-poly(vinyl methyl ether) (PS-PVME), is studied below the glass transition, via dielectric relaxation spectroscopy. A particular attention has been paid to blends with a high PS content (PS weight fraction higher than 50%). A relaxation process, slower than the localized motions inducing the PVME secondary relaxations, is detected. Even though these blends fall out of equilibrium in this temperature regime, the structural recovery process is not efficient on the time scale of this PVME motional process. This relaxation is attributed to rather localized, weakly cooperative PVME motions resulting from the topological constraints imposed by the frozen PS chains.
通过介电弛豫谱，研究了低于玻璃化转变温度时，聚合物共混物中低T(g)组分（动态不对称聚苯乙烯-聚（乙烯基甲基醚）（PS-PVME））的局部动力学。特别关注了高PS含量（PS重量分数高于50%）的共混物。检测到一个弛豫过程，其速度比诱导PVME二级弛豫的局部运动慢。尽管这些共混物在该温度范围内偏离平衡，但在该PVME运动过程的时间尺度上，结构恢复过程并不有效。这种弛豫归因于由冻结的PS链施加的拓扑约束导致的相当局部化、弱协同的PVME运动。
