Abstract
It is a well known fact that a flow curve of polymer solution has a correlation to the molecular weight of the polymer. In this paper the flow curve is examined in anticipation that the flow curve of viscose has a correlation to not only the DP of cellulose, but also to the state of solution of viscose.
Four kinds of viscose which differ in the state of solution were prepared by varying DP of cellulose, distribution of DP, concentration of cellulose and r value. The flow curve was obtained by using a rotationary viscometer. To get a parameter which represents the characteristics of the flow curve, the flow curve was transformed into a straight line by plotting the viscosity (=1/fluidity) against shearing stress in a definite range. As parameters a slope of line “d” and an “intercept value” at shearing stress of 104 dyne/cm2 were chosen. These parameters were compared on the above mentioned viscoses.
The following results were obtained:
The parameter “d” increases with DP of cellulose and decreases with the concentration of cellulose in viscose. The γ value has no effect on the value of “d”. Ununiformity of the distribution of DP tends to make the value of “” larger. However the parameters are strongly dependent on the concentration and DP of cellulose. As there is little difference between the parameters before and after filtration of any viscose, a conclusion that the flow curve is of little value on evaluation of the state of solution of viscose within a range of this experiment can be drawn.
