ABSTRACT

A Capillary Break-up Extensional Rheometer (CaBER) was modified to enable measurements of the axial force in combination with the related displacement. This makes it possible to determine the separation energy $W_{sep}^N$, the tackiness, of a polymer solution between two parallel plates with the CaBER. Separation energies of solutions of linear polystyrene, comb polystyrene and linear poly(methyl methacrylate) in dimethylformamide were measured as model systems. For linear polymers at a critical polymer concentration, there was a drastic change in slope of the separation energy $W_{sep}^N\left(c\right)$. This critical concentration was shown to be the minimum concentration at which continuous bead-free fibers could be electrospun.

摘要

修改了毛细管破裂流变仪（CaBER），以结合相关位移测量轴向力。这样就可以确定分离能${\mathrm{w\; ^}}_{sËp}^{ñ}$使用CaBER在两块平行板之间的聚合物溶液的粘性。测量线性聚苯乙烯，梳状聚苯乙烯和线性聚（甲基丙烯酸甲酯）在二甲基甲酰胺中的溶液的分离能。对于处于临界聚合物浓度的线性聚合物，分离能的斜率发生了急剧变化${\mathrm{w\; ^}}_{sËp}^{ñ}\left(C\right)$。该临界浓度显示为可连续纺丝无珠纤维的最低浓度。