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对低温聚合丁苯橡膠一个级分(M=1.0×10~6)的甲苯溶液在切变速度 D=10—20,000秒~(-1)范国内测定了五种浓度溶液的粘度数据(25.0℃)。粘度计采用 Tsuda 的水平毛细管水平流出体积计量管的设计,且在全部切变速度范围内都从同一毛细管流出,使不同范围内的数据很好衔接。实验结果证明在低切变速度区域牛顿粘度η(?)(0)的存在。并且从lnη(?)—ln D 曲线的反曲点(?)值不依赖于浓度和对反曲点的对称性估计η(?)(∞)值和整个切变速度范国内的粘度行为。取几个等 D 值时的 lnη(?)按(lnη(?)/C)-C 的线性外推得到[η]_D,明确表示在低切变速度区域[η](?)的存在。两种牛顿流动间转变区域的实难数据可以采用下列两公式线性化:x(D)=(1/2)[1-erf(kln(?))],x(D)=(1/1+(?))~n,式中x=(lnη(?)-lnη(?)(∞)/lnη(?)(0)-lnη(?)(∞)),erf(z)=(?)-u~2du,k 和 n 是依赖于浓度的参数,但在较高浓度时均趋向一恒定值。([η]_D/[η]_0)-ln D 曲线相当符合于刚性橢球轴比 p=4—5间的理论曲线,这样得到的转动扩散系数(?)_(rot)=6.6×10~2秒~(-1),但是从(?)_(rot)和[η]_0值按 Scheraga-Mandelkern 方法计算得到的分子量值与实际不符,所以丁苯橡膠分子线团不是刚性结构;而以1/(?)值作为高分子线团弹性变形的松弛时间,按 Bueche 理论计算得到的分子量值与实际极相一致。
The viscosity data of five concentration solutions (25.0 ℃) were measured in a toluene solution with one fraction (M = 1.0 × 10 ~ 6) of low temperature polymerization of styrene butadiene rubber at shear rate D = 10-20,000 s -1 ). The viscometer utilizes Tsuda’s horizontal capillary horizontal outflow metering tube design and flows out of the same capillary tube at all shear rates, allowing good data connectivity across the range. The experimental results demonstrate the existence of Newtonian viscosity η (?) (0) in the low shear rate region. And the viscosity behavior of the η ()) (∞) value and the whole shear rate are estimated from the values of the inflection point (Δ) of the curve of lnη (?) - ln D, independent of the concentration and the symmetry of the inflection point. Taking a few values of D for η (η) and η (η) for the linear extrapolation of (lnη (?) / C) - C, it shows the existence of [η] The hard data for the transition between two Newtonian flows can be linearized using the following two equations: x (D) = (1/2) [1-erf (kln (?))], X + (?)) ~ n where x = (lnη (?) - lnη (?) (∞) / lnη (?) (0) -lnη (?) ) -u ~ 2du, k and n are concentration-dependent parameters but tend to be constant at higher concentrations. The curve of [η] _D / [η] _0) -ln D is in good agreement with the theoretical curve of rigid ellipsoid axis ratio p = 4-5. The rotative diffusivity (?) = ~ 2 seconds ~ (-1), but the molecular weight calculated by the method of Scheraga-Mandelkern from (?) - (rot) and [η] _0 values does not match with the actual value, so the SBR molecular coil is not a rigid structure; The value of 1 / (?) Is taken as the relaxation time for the elastic deformation of macromolecule threads, and the molecular weight calculated by Bueche theory is consistent with the actual polarity.