Capillary breakup extensional rheometry of semi-dilute polymer solutions
Capillary breakup extensional rheometry of semi-dilute polymer solutions
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半稀聚合物溶液的毛细管破裂拉伸流变测定
DOI：
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发表时间：
2010
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通讯作者：
C. Clasen
中科院分区：
文献类型：
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作者：
C. Clasen
本文用毛细管断裂拉伸流变仪研究了聚苯乙烯在邻苯二甲酸二乙酯中的半稀溶液的细化和断裂。该解决方案显示出长的初始粘-毛平衡，可以与0-D牛顿和幂律模型拟合。弹性毛细平衡的开始是分子量依赖性的，并且聚合物的线圈拉伸转变被移动到接近断裂点和小的长丝直径。然而，过渡是均匀的浓度高达c/c* ~ 30观察到的，由于在Caber实验中的一个强大的扩展变薄。结果表明，当局部弹性-毛细管数Ec* = 4.7时，体系发生向弹性-毛细管平衡的转变，其中包括拉伸松弛时间λE和拉伸稀化粘度ηE，app。
In this paper the thinning and breakup of filaments of semi-dilute solutions of polystyrene in diethyl phthalate is investigated with a capillary breakup extensional rheometer. The solutions show a long initial viscocapillary balance that can be fitted with 0-D Newtonian and power law models. The onset of the elastocapillary balance is molecular weight dependent and the coil stretch transition of the polymer is shifted close to the breaking point and to small filament diameters. However, the transition is even for concentrations up to c/c* ~ 30 observable due to a strong extension thinning in the Caber experiment. It is shown that the transition to the elasto-capillary balance takes place at local elasto-capillary number Ec* = 4.7 that incorporates the extensional relaxation time λE and the extension thinning viscosity ηE,app.