Spontaneous pinning of domain growth during spinodal decomposition of off‐critical polymer mixtures
Spontaneous pinning of domain growth during spinodal decomposition of off‐critical polymer mixtures
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非临界聚合物混合物旋节线分解过程中域生长的自发钉扎
DOI：
10.1063/1.463562
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发表时间：
1992
影响因子：
4.4
通讯作者：
T. Izumitani
中科院分区：
文献类型：
--
作者：
T. Hashimoto;M. Takenaka;T. Izumitani
用时间分辨光散射法研究了聚(苯乙烯-无规丁二烯)共聚物与聚异戊二烯或聚丁二烯的亚临界混合物的调幅分解随混合物组成w和相分离温度T的变化。根据最大强度Im的时间变化和达到最大强度的散射矢量Qm的大小的时间变化来表征混合物的粗化行为。结果表明，对于本文所研究的非临界混合物，Im和Qm的时间变化在这里定义为“钉扎”时间的某一时刻被有效地钉扎。对于这些似乎具有较高临界溶液温度行为的体系，当w在给定的T处偏向0或1时，当相分离温度在给定的w处升高时，这种自发钉扎结构的生长发生得更早。
Spinodal decomposition of off‐critical mixtures of poly(styrene–random–butadiene) copolymer with polyisoprene or polybutadiene was investigated as a function of the composition w of the mixtures and of the phase separation temperature T by time‐resolved light scattering. The coarsening behavior of the mixtures was characterized in terms of the time change of the maximum intensity Im and that of the magnitude of the scattering vector qm at which the intensity becomes maximum. It was found that the time changes of Im and qm for the off‐critical mixtures studied here are effectively pinned at a certain time defined here as the ‘‘pinning’’ time. This spontaneous pinning of the growth of the unmixing structure was found to occur earlier when w is biased toward 0 or 1 at a given T and when the phase separation temperature is raised at a given w, for these systems which seemingly have upper critical solution temperature behavior.