Dynamics of Spinodal Decomposition in Critical Polymer Mixtures

临界聚合物混合物中的调幅分解动力学

基本信息

批准号：
60470100
负责人：
KUWAHARA Nobuhiro
金额：
$ 2.3万
依托单位：
Gunma University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

项目摘要

Dynamics of phase separation has been studied near the upper critical mixing point ( <T_c> =34.42゜C, <W_c> =12.1 wt.%) of the system polydimethylsiloxane (PDMS, <M_n> <-![> <M_w> =80 x <10^3> )-diethyl carbonate (DEC) and the lower critical mixing point ( <T_c> =31.89゜C, <W_c> =1.20 wt.%) of the system pentaethylene glycol dodecyl ether ( <C_(12)> <E_5> )-water (W). The gist obtained is as follows.1. The system <C_(12)> <E_5> -W near its critical mixing point deviates from the universality class of fluids, binary mixtures, and alloys near their critical points.2. When the critical mixture of PDMS-DEC and of <C_(12)> <E_5> -W are suddenly brought into the inside of their spinodal curves, clusters in the minority phase grow gradually and the forward scattered-light intensity I forms the maximum peak <I_m> at momentum transfer k= <k_m> .1) For PDMS-DEC at <T_c> -T <-![> 5 mK the light intensity I(k,t) increases in accordance with I(k,t)[ <t^(1.5)> at momentum transfer k=2.5 x <10^3> <cm^(-1)> for a time of t <<![> 60 sec, I(k,t)[ <t^(2.5)> at k=1.6 x <10^3> <cm^(-1)> over 60 sec <<![> t <<![> 130 sec, and then the peak of scattered light at k= <k_m> increases sharpness and shifts to smaller k with time in the range of t <>![> 190 sec.2) For <C_(12)> <E_5> -W at T- <T_c> <-![> 1 mK, I(k,t) increases in accordance with I(k,t)[ <t^(2.3)> at k=2.1 x <10^3> <cm^(-1)> for a time of t <<![> 50 sec, I(k,t)[ <t^(3.4)> at k=1.5 x <10^3> <cm^(-1)> over 50 sec <<![> t <<![> 100 sec, and then the peak of scattered light at <k_m> increases sharpness and shifts to smaller k with time in the range of t <>![> 130 sec.3. The wave length <RAMbda> (=2 <pi> /k) of concentration fluctuations in the early stage of spinodal decomposition is 26 <mu> m for PDMS-DEC at <T_c> -T <[!-> 5 mK and 29 <mu> m for <C_(12)> <E_5> -W at T- <T_c> <-![> 1 mK.

研究了聚二甲基硅氧烷系统 (PDMS, <M_n> <-![> <M_w> =) 上临界混合点 ( <T_c> =34.42゜C, <W_c> =12.1 wt.%) 附近的相分离动力学80 x <10^3> )-碳酸二乙酯 (DEC) 和较低的临界混合点 ( <T_c>体系五乙二醇十二烷基醚(<C_(12)><E_5>)-水(W)=31.89゜C，<W_c>=1.20wt.%)得到的要点如下。 1． C_(12)> <E_5> -W 在其临界混合点附近偏离流体、二元混合物和合金在其临界点附近的普遍性类别。2．当PDMS-DEC和<C_(12)><E_5>-W的临界混合物突然进入其旋节线曲线内部时，少数相团簇逐渐生长，前向散射光强度I形成最大值动量传递处的峰值 <I_m> k= <k_m> .1) 对于 <T_c> -T <-![> 5 mK 处的 PDMS-DEC，光强度 I(k,t) 根据以下公式增加I(k,t)[ <t^(1.5)> 动量传递 k=2.5 x <10^3> <cm^(-1)> 时间 t <<![> 60 秒，I(k ,t)[ <t^(2.5)> 在 k=1.6 x <10^3> <cm^(-1)> 超过 60 秒 <<![> t <<![> 130 秒,然后 k= <k_m> 处的散射光峰值会增加清晰度，并随着时间在 t <>![> 190 秒范围内移动到较小的 k。2) 对于 <C_(12)> <E_5> -W at T- <T_c> <-![> 1 mK，I(k,t) 根据 I(k,t)[ <t^(2.3)> 在 k=2.1 x <10^3> 处增加<cm^(-1)> 时间为 t <<![> 50 秒，I(k,t)[ <t^(3.4)> 在 k=1.5 x <10^3> <cm^(- 1)> 超过 50 秒 <<![> t <<![> 100 秒，然后 <k_m> 处的散射光峰值会增加锐度，并在 t 范围内随时间移动到较小的 k <>![> 130 sec.3. PDMS-DEC 在 <T_c> 时，旋节线分解初期浓度波动的波长 <RAMbda> (=2 <pi> /k) 为 26 <mu> m T <[!-> 5 mK 和 29 <mu> m 对于 <C_(12)> <E_5> -W at T- <T_c> <-![> 1 mK。