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亲们，江湖告急，求翻译。
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Fig. 1(b) shows that the reaction time greatly influences the water absorbency of the resin, which increases with time. When the reaction time was 4 h, the resin water absorbency in distilled water was 1083.9 g/g, and 95.62 g/g in 0.9 wt.% NaCl. At a reaction time of 5 h, the resin water absorbency decreased. These observations are in line with the free radical reaction rule, which states that if the reaction time is too short, polymerization does not proceed to completion and results in low relative molecular mass and small network size after swelling with low resin water absorbency. Therefore, the prolonged reaction time can increase the degree of polymerization at the beginning of the reaction. Steady-state polymerization was reached after 4 h of reaction. In this stage, the generation rate of the free radical is equal to its consumption rate, which establishes a dynamic equilibrium wherein the reaction time has no influence on water absorbency. On the other hand, a very long reaction time causes the degradation of resin and results in a low molecular weight (Xu, Li, & Sun, 2010). In addition, stirring causes shear stress in the reaction system for a long time, thereby decreasing its viscosity. The decrease in viscosity is not conducive to polymerization, therefore, decreases the water absorbency. |
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RXMCDM: 金币+1, 多谢应助！ 2014-10-16 23:28:11
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| 图1（b）表明，反应时间极大地影响着树脂的吸水率，其随时间而增加。当反应时间为4小时时，树脂在蒸馏水中的吸水率是1083.9克/g，在0.9％的NaCl（重量百分比）中则为95.62克/克。当反应时间为5小时时，树脂的吸水率降低。这些观察结果与自由基反应的规则相符，该规则规定，如果反应时间过短，聚合会不完全，导致形成一些分子质量相对低的产物，溶胀后网络的大小小，树脂的吸水率低。因此，延长反应时间在反应的开始就可以提高聚合度。反应4小时后达到稳态聚合。在稳态聚合阶段，自由基的生成速率和其消耗速率是相等的，建立了一个动态平衡，所以此时反应时间对吸水率没有影响。在另一方面，过长的反应时间会引起树脂的降解并产生低分子量产物（(Xu, Li, & Sun, 2010）。另外，搅拌在反应体系中引起剪切应力，长时间后可降低其粘度。粘度降低不利于聚合反应，因此降低了吸水性。 |
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3楼2014-10-18 20:52:49
