Viscosity-temperature relationships for dilute solutions of cellulose derivatives: II. Intrinsic viscosities of ethyl cellulose

摘要: Abstract Temperature variations of intrinsic viscosities and some other viscosity parameters for ethyl cellulose fractions in representative solvents are considered terms current hydrodynamic thermodynamic treatments the dilute polymer solutions. The value [η] decreases strongly with increasing temperature, dependence being approximately linear. temperature coefficient appears to be linearly related molecular weight polymer. Except case chloroform, which aggregation may occur, values exponent a expression = KMa decrease slightly increase suggesting decreasing chain extension. Values Porod-Kratky persistence length q, Kirkwood-Riseman effective bond b, angle between successive planes chains suggest stiffness as increases. Flory treatment is applied obtain qualitative information regarding contributions different factors negative coefficients [η], that these primarily due ( r 0 2 M) , where mean-square unperturbed end-to-end distance M weight. its solvent briefly discussed.