【摘要】 作者等使用一种全部由玻璃制成的管形渗透计,半透膜用硝化纤维素溶液涂在熔结玻璃筒的外面,经脱硝基处理后使用。玻璃筒内置溶剂,筒外置溶液。这种渗透计构造简单,操作简便,特别适合于对混合溶剂、粘度大的溶液和在几个温度下的渗透压测量。聚甲基丙烯酸甲酯一个级份（M_n=6.3×10⁵）在甲苯-乙醇溶液里的渗透压和粘度数据（25°）指示γ=0.17（沉淀剂的体积分数）时A₂和[η]都呈现最大值。各溶液的粘度都微有切变速度依赖性,与牛顿流动的偏差亦在γ=0.17附近最大。在C=1×10^-3克/厘米³时的沉淀点γ=0.68₂。更多还原

【Abstract】 A new type all-glass osmometer of very simple construction using asintered glass cylinder as rigid support for de-nitrated collodion membrane isdescribed. The solvent is put inside the osmotic cell and the solution outside.Not more than 10 ml of solution is needed for a determination, while theamount of solvent used is extremely small. No special technique is requiredfor the manipulation of the osmometer. It is especially suited for theosmometric studies with mixed solvents, for very viscous solutions and formeasurements at several temperatures. A polymethylmethacrylate fraction （M_n=6.3×10⁵） was dissolved invarious mixtures of toluene-ethanol for osmometric and viscometric studies.Osmotic pressure data show that the value of A₂ goes through a maximum atthe volume fraction of ethanol γ= 0.17, and γ（A₂= 0） = 0.67 estimated fromthe initial slopes of the л/C vs C plots which are appreciably curved. The values of intrinsic viscosity also show a maximum at γ= 0.17, and inthe whole range of the mixed solvents the values of [η] and A₂ are symbatic.The solution viscosity shows slight shear rate dependence, and the deviationfrom Newtonian flow is greatest arround γ= 0.17 and becomes very smallnear the precipitation point, which occurs at γ(c= 1.10^-3g/cm³)= 0.68₂. The experimental results indicate that the polymer coil is most expandedat γ= 0.17, where A₂ and [η] values are at their maximum and the solutionviscosity shows greatest shear rate dependence. This seems reasonable as thecohesion energy density of polymethylmethacrylate （12.2） lies between those oftoluene （8.94） and ethanol （12.80）.更多还原