分子量分布が狭い高分子流体の分子量と非ニュートン粘度の関係について

概要

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The non-Newtonian viscosity derived from the previously proposed constitutive equation was expressed as follows, [numerical formula] where H(λ) was the relaxation spectrum and λ,γ^^・, and β were the relaxation time, shear rate and a nondimensional parameter of order 1, respectively. When polymers are approximated in their narrow-distribution H(λ) by [numerical formula] the non-Newtonian viscosity calculated from these equations can be superposed as shown in Fig.1. If λ_1 is replaced by the natural time λ_N defined by λ_N=η(0)J(0), which is more directly related to measurable quantities, the reduced shear rate in Fig.1 becomes [numerical formula] were J(0) is steady-state compliance and δ_s=1+1.8δ^0.86_0. Prest's data of J(0) are expressed in terms of entanglement density E as follows [numerical formula] where I_<Rc> is the Rouse steady-state compliance at the critical molecular weight M_c. If this experimental equation is used with assumptions that β is independent of M and δ^<-1>_0=E, the relation between the characteristic time λ_<ch> and M is to be expressed as [numerical formula]. This is in the same relation as Graessley's and is applied to the narrow distribution of polydimethyl siloxane melts with fairly good agreement as shown in Fig.2. The solid line in this figure shows the viscosity curve at δ_0=1 in Fig.1.
社団法人日本材料学会の論文
1972-05-15