On the partially free draining effect in the intrinsic viscosity and sedimentation coefficient of cellulose nitrate solution

Abstract

The partially free draining effect on intrinsic viscosity, sedimentation and diffusion constant was evaluated for cellulose nitrate solution. The methods used iu this study involve the analysis of (a) parameters in the KUHN-MARK-HOUWINK-SAKURADA equation, (b) intrinsic viscosity [q] and concentration dependence of sedimentation coefficient k,, (c)[q], k,, molecular weight M, and second virial coefficient Az, (d) molecular weight dependence of sedimentation constant and the exponent Q in the KUHN-MARK-HOUWINK-SAKU-RADA equation, (e) Q and molecular weight dependence of diffusion constant, (f) a and dependence of [q] on radius of gyration of a polymer chain R, (g) Q and molecular weight dependence of R, (h) [q], M, R, and the linear expansion factor a, (i) [q], M, and Az. Draining parameters thus obtained, such as X, v(X), and A which were defined in the theories of KURATA-YAMAKAWA and KAWAI-KAMIDE, are compared with those in literature. Although the methods used here have been derived from different theoretical bases using different approximations, v(X) was evaluated as 0.3 + 0.1 for cellulose nitrate with nitrogen content of 12 to 14%, irrespectively of the method used. This indicates that the draining effect can not be ignored, in other words, the intrinsic viscosity and sedimentation data can not be interpreted reasonably by the excluded volume theories without taking into account the draining effect. ZUSAMMENFASSUNG: Fur Losungen von Cellulosenitrat wird der Effekt der teilweisen freien Durchspiilbarkeit ermittelt. Dazu werden folgende GroBen analysiert : (a) die Parameter der KUHN-MARK-HOUWINK-SAKURADA-Gleichung, (b) die Viskositatszahl [q] und die Konzentrationsabhangigkeit k8 des Sedimentationskoeffizienten S, (c) [q], k,, M und zweiter Virialkoeffizient Az, (d) die Molekulargewichtsabhangigkeit von S und Q, (e) Q und die Molekulargewichtsabhangigkeit des Diffusionskoeffisienten, (f) Q und die Abhangigkeit von [q] vom Tragheitsradius R, ( 9 ) die Molekulargewichtsabhangigkeit von R und a, (h) M, R und der lineare Ausdehnungskoeffizient a, (i) [q], M und A2. Parameter fur die Durchspiilbarkeit wie X, v(X) und A aus den Theorien von KURATA-YAMAKAWA und KAWAI-KAMIDE werden mit Literaturwerten verglichen. Obwohl die benutsten Methoden auf verschiedenen Grundlagen beruhen und unterschiedliche Naherungen darstellen, wurde fur alle Methoden v(X) zu 0,3 & 0,l fur Cellulosenitrat mit 12-14y0Stickstoffgehalt gefunden. Das zeigt, daB Viskositats-und Sedimentationsdaten nicht allein durch die Theorie des ausgeschlossenen Volumens vernunftig interpretiert werden konnen. Der Effekt der Durchspulbarkeit mu13 aul3erdem berucksichtigt werden.

The Partially Free Draining Effect and Unperturbed Chain Dimensions of Cellulose, Amylose, and their Derivatives

“…(4) If both the free draining effect and nongaussian nature of a chain are reasonably taken into account, the reliable parameter A can be determined by using the thermodynamic (2D) or hydrodynamic approach (2G), proposed here. (5) Cellulose, amylase and their derivatives are not flexible, but semi-or inflexible polymers, and their dilute solution properties can not be explained by the "two-parameter" theory whose validity was widely confirmed for numerous vinyltype polymers.…”

“…This conclusion was already drawn for CN previously by Kamide. 5 An attempt was made to check the consistency among the methods utilized for estimating the unperturbed chain dimensions. For this purpose, the correlation coefficient r was calculated for any two methods arbitrarily chosen.…”

“…The molecular weight dependence of the limiting viscosity number can be expressed by the Mark-Houwink-Sakurada (MHS) equation, ( 4) where Km and a are parameters characteristic of a given polymer-solvent system and temperature. The exponent a in eq 4 can be devided into three parts 4 a=0.5+1,1(X)+n(X)s+I.Sa2 ( 5) where e=dln a 0/ dln M ( 6) a 2=d In ((S 2 ) 0 /M)/d In M…”

“…(3) In a treatment of the solution properties of these polymers (method 2B in this paper), the excluded volume parameter z are evaluated from the penetration function ¢ (eq 21), and are found to be less than unity. This indicates that the expansion factor as is only slightly larger than unity, (5) In another treatment, the unperturbed chain dimensions are estimated from the experimental data on [17] and M(Method 2E) through use of the Stockmayer-Fixman equation (eq 40) or similar equations. The result shows that cellulose and amylose chains are quite flexible and the solvents involved are good.…”