Measurement of the average viscometric degree of polymerization of new and aged cellulosic electrically insulating materials
|Publication Date:||1 July 2007|
|ICS Code (Insulating materials in general):||29.035.01|
|ICS Code (Other standards related to electricity and magnetism):||17.220.99|
This International standard describes a standardized method for the determination of the average viscometric degree of polymerization n ( DPν ) of new and aged cellulosic electrically insulating materials. It may be applied to all cellulosic insulating materials such as those used in transformer, cable or capacitor manufacturing.
The methods described can also be used for the determination of the intrinsic viscosity of solutions of chemically modified kraft papers, provided that these dissolve completely in the selected solvent.
Caution should be taken if the method is applied to loaded kraft papers.
NOTE Within a sample of material, all the cellulose molecules do not have the same degree of polymerization so that the mean value measured by viscometric methods is not necessarily the same as that which may be obtained by, for instance, osmotic or ultra centrifuging methods.