ポリプロピレン溶融物の線形粘弾性と毛細管定常流動性との関係
スポンサーリンク
概要
- 論文の詳細を見る
It is the object of the present study to obtain clear knowledge of the relations in the polypropylene melt between its linear viscoelasticity and its non-linear steady capillary flow, paying particular attention to the elastic properties in its capillary flow. By representing the linear viscoelasticity numerically with zero-shear viscosity, η_o, and steady-state compliance, J_e^0, evaluation has been made of the properties concerning the elasticity of polymer in the capillary flow, such as non-Newtonianity, the entrance pressure loss, the end correction, the Barus effect and the melt fracture. The steady flow viscosity, η, the entrance pressure loss, P_o, the critical shear stress,τ_c, and the critical shear rate, γ^^・_c, at which melt fracture begins to occur, are subject to η_o as follows : logη∝logη_o, logP_o∝logη_o, τ_c∝-logη_o, logγ_c∝-logη_o. From the well-known relationship between η_o and the average molecular weight, M^^-_w, these quantities are governed by M^^-_w. Meanwhile, for such quantities as structural viscosity index, N, end correction coefficient, ν, and elastic pressure loss ratio, P_o/P, following correlations hold : N∝log(η_o, J_e^0), logν∝log(η_o^2・J_e^0). As η_o and J_e^0 are respectively determined mainly by M^^-_w and the molecular weight distribution, M. W. D., these quantities are governed by both M^^-_w and M. W. D. Physical meanings of η_o・J_e^0 and η_o^2・J_e^0 are respectively mean relaxation and a measure of stored energy in steady flow. Barus effect has positive correlation to J_e-o, ν and P_o/P The symbol employed here, ∝, means the positive correlation.
- 社団法人日本材料学会の論文
- 1971-05-15