期刊
MACROMOLECULES
卷 41, 期 21, 页码 8030-8037出版社
AMER CHEMICAL SOC
DOI: 10.1021/ma8010526
关键词
-
资金
- National Science Foundation [DMR-0355470, CHE-9629688]
Deuterium NMR at Larmor frequencies of 15.6 and 76.7 MHz was used to study the segmental dynamics of perdeuteriopoly(ethylene oxide) (d(4)PEO) in miscible blends with poly(vinyl acetate) (PVAc). Blends with PEO compositions of 2% and 50% were studied. The segmental dynamics of PEO are 9 orders of magnitude faster than the PVAc segmental dynamics for a 2% PEO blend near the blend T, and could be described by the Lodge-McLeish model with a self-concentration of 0.3. The segmental dynamics of PEO in blends with PVAc show a weaker temperature dependence than the terminal dynamics of PEO in the same blends. We also compare the segmental and terminal dynamics of components in several other miscible polymer blends. For the fast component in a blend, it is commonly observed that terminal relaxation has a stronger temperature dependence than segmental relaxation. This effect correlates with the difference between the T-g values for the pure components and also with the ratio of the activation energies of the segmental dynamics for the two components in the blend.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据