交联网络和浓溶液中高分子链运动的NMR研究 Ⅱ质子自旋-自旋弛豫与凝胶和浓溶液体系中高分子链段运动
The NMR Studies of Macromolecular Segement Movement in Crosslink Network and Concentrated Solution 2. Proton Spin-Spin Relaxation vs Macromolecular Segment Movement in Gel and Concentrated Polymer Solution Systems
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摘要: 用自旋-自旋弛豫时间考察了线型聚苯乙烯溶液与溶胀交联聚丙烯酰胺-丙烯酸凝胶的质子弛豫行为。发现在溶胀交联体系中,不论交联度高低,聚丙烯酰胺-丙烯酸质子的弛豫时间弛豫都呈现出双指数衰减特征;而在线型溶液体系中,聚苯乙烯质子的弛豫时间弛豫符合单指数衰减特征。说明在线性聚苯乙烯溶液中,高分子的链段运动是一种均匀行为,而在溶胀交联聚丙烯酰胺-丙烯酸体系中,不论交联度高低,高分子链段运动始终存在快慢不同的两部分。Abstract: The spin-spin relaxation time (T 2) is used to study the proton relaxation behavior in crosslinked (polyacrylamide-acrylic acid) (P(AAM-AAc)) network and linear polystyrene (PS) solution. It is found that the proton T 2 relaxation time of P(AAM-AAc) sh