Shuichi Uchiyama

EFFECTS OF DISSOLVING CONDITION OF POLYACRYLONITRILE ON SOLUTION VISCOSITY AND ITS STABILITY

Acrylonitirle polymer was dissolved by heating the polymer and dimethyl formamide for 1, 2 and 3hrs. at 50°C and then for 1, 2, 3 and 4hrs. at 80°C. Polymer concentration of the solution was 26 wt. %. Then the solution was kept at 50°C for 0, 2, 4 and 6 days and falling ball viscosity was measured. Viscosity increase up to 6 days was calculated.The results obtained are as follows:1) The dissolving time at 50°C has no influence upon solution viscosity.2) The solution dissolved for longer time at 80°C has larger viscosity as well as larger viscosity increase after 6 days.

EFFECTS OF THE ADDITION OF THE THIRD COMPONENTS ON ACTIVATION ENERGY FOR FLOW AND APPARENT VISCOSITY OF CONCENTRATED CELLULOSE ACETATE SOLUTION

A third component, such as inorganic compounds, organic compounds and high polymer, was added to a concentrated solution of cellulose acetate.The activation energy for flow of the solution was calculated from temperature dependency of the falling ball viscosity.The apparent viscosiy was measured with a cone-plate viscometer at various shear rates. The results obtained are as follows:1) CaCl2 has a tendency to increase the activation energy with its certain contents and coupling is considered to form in solution. But CaCl2 decreases the energy over that content.2) Organic compounds such as methyl ethyl ketone, nitromethane and glyoxal increase the activation energy considerably. But chloroform and CCl4 do not increase it so much.3) High polymers such as polyvinyl chloride and polyvinyl acetate form some couplings in the solution, but other high polymers do not increase the energy so much.4) The relationship between η and D is as follows;η=CDd (C and d are constants.)where η is the apparent viscosity and D the shear rate.The solution with larger |d| has larger activation energy for flow.5) The solution containing a substance to increase the activation energy shows an abnormal viscosity at a certain shear rate.