In this study, we have proposed a theory which was derived from the Ree-Eyring theory of non-Newtonian flow, and predicts the normal stress coefficient.
The flow parameteric values appearing in our viscosity equation were obtained by applying our theory to experimental values of viscosity for various systems. By using the parameteric values of $\beta_1$ and $X_i\beta_i/\alpha_i$ (i = 1 or 2) the values of $\eta$ were recalculated from our theoretical equation. The theoretical values of $\eta$ were compared with experiment for various viscoelastic materials. We found that the agreement between theory and experiment is excellent. By using the parameteric values, the normal stress coefficients ratio $\Theta/\Theta_o$ were also calculated from our normal stress coefficient equation. For viscoelastic materials investigated in this study, the agreement of the theory with experiment was satisfactory. Viscoelastic materials investigated in this study are listed below:
7.0% aluminum soap solution, post mortem synovial fluid, 2.5wt polystyrene, 4.0wt% polystrene, 5.0wt% polystyrene, 0.75wt% polyacrylamide, 1.5wt% polyacrylamide, 2.0wt% polyisobutylene, 5.0wt% polyisobutylene, HDPE melt, LDPE melt, polypropylene melt and phenoxy-A melt.
본 연구에서 non-Newtonian flow의 Ree-Eyring식을 사용하여 normal stress coefficient를 예언하는 이론을 제안했다.
점도식에 있는 flow parameter 값들은 점도의 실험값에 Ree-Eyring 이론을 적용하여 구하였다. parameter값 $\beta_i$와 $x_i \beta_i/\alpha_i (i = 1, 2)$을 사용하여 이론식으로써 점도값을 다시 계산하였다. 여러가지 점탄성물질에서 점도값과 실험값을 비교해 본 결과 잘 일치했다. normal stress coefficient비 $\theta/\theta_o$는 제안한 normal stress coefficient 식에 parameter값을 사용해서 계산했다. 본 연구에서 고찰한 점탄성물질에서는 이론과 실험이 만족할만큼 일치했다. 이들 물질은 아래에 나열되어 있다.
7.0% aluminium soap 용액, post mortem synovial fluid, 2.5wt% polystyrene, 4.0wt% polystyrene, 5.0wt% polystyrene, 0.75 wt% polyacrylamide, 1.5wt% polyacrylamide, 2.0wt% polyisobutylene, 5.0wt% polyisobutylene, HDPE melt, LDPE melt, polypropylenemelt, phenoxy-A melt.
