DYNAMICS IN POLYDIMETHYLSILOXANE - THE EFFECT OF SOLUTE POLARITY

被引:23
作者
DIACHUN, NA [1 ]
MARCUS, AH [1 ]
HUSSEY, DM [1 ]
FAYER, MD [1 ]
机构
[1] STANFORD UNIV,DEPT CHEM,STANFORD,CA 94305
关键词
D O I
10.1021/ja00082a025
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
The temperature dependent dynamics of polydimethylsiloxane (PDMS) melts are investigated by measuring orientational relaxation of a dissolved probe molecule, 2-naphthyltriethoxysilane (NTES) using time resolved fluorescence depolarization. The temperature dependent viscosity of PDMS is also reported for two molecular weights. The measurements of nonpolar NTES probe dynamics:are compared to previous measurements on the polar probe, N-(triethoxysilylpropyl)dansylamide. The activation energies for the orientational relaxation of the two probes are very different. This is discussed in terms of the influence of the polarity of the solutes an the local structure in the melts. The results have implications for possible modifications of the physical properties of PDMS materials by using solutes or side groups of varying polarity. The synthesis of the NTES probe, which can also be used as a cross-linking reagent for PDMS, is also described.
引用
收藏
页码:1027 / 1032
页数:6
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