Molecular weight distribution of different cellulosic substrates

Team leader: Paul Kosma (University of Natural Resources and Applied Life Science, Austria)

Abstract:
Molecular weight distribution profiles of celluloses by analytical GPC using different methods and analytical setups will be compared. In addition, influence of column age, derivatization, solvent systems, laser wavelengths and data evaluation will be analyzed. After the data of the round robin test are thoroughly evaluated further tasks to develop an optimized standard EPNOE procedure should be performed (not yet financed).

Objectives:
The precise and reliable determination of the molecular weight is of outmost and fundamental importance to almost any of EPNOE research activities. In particular the knowledge on the molecular weight is an indispensable tool to
Characterize native polysaccharide materials and pulp
Evaluate the impact of isolation and extraction conditions on degradation of raw materials
Establish relationships with process behaviour such as swelling and solubility and product properties (e.g. tensile strength)
Follow-up of any changes introduced during further processing into cellulose derivatives and regeneration
In particular, Fundamental Theme 2 will benefit using this common tool, since any enzymatic, chemical or physical pretreatment can be monitored. Furthermore, potential degradation reactions which may take place in ionic liquids can be documented and changes of product properties due to hydrolytic or aging conditions can be detected. Similarly, topics of Fundamental Theme 1, Fundamental Theme 3 and Fundamental Theme 4 will profit from this activity.

Importance for EPNOE community and industrial partners:
Standard methods for cellulose analysis will serve as an important method for the characterization of cellulose during different processing steps and is hence a potential source to generate interaction with industrial partners of different kinds. Within the EPNOE community a standard method will serve as supporting tool to many areas of research within the partners to characterize changes at cellulose, e.g. in cellulose functionalisation or evaluating polymer integrity.

Importance for the characterisation of the polysaccharide raw materials and process control:
The method allows for a detailed analysis of the Mw distribution of celluloses and hemicelluloses, which depends on the origin of the native material, growth conditions, cooking and bleaching and activation conditions. These changes in the molecular properties induced by the production process translate into a variability of product properties and thus limit the applicability of polysaccharide materials in general.

Importance for the characterisation of polysaccharides processability:
GPC of Cellulose and the data generated with this method belong to one of the most important parameters in processing of pulp (e.g. for the production of fibres and cellulose derivatives)

Applicability to the different kind of polysaccharides:
Close relations to starch GPC although in a completely different solvent system do exist.

Potentiality to transform them into marketable products:
The method itself can be transformed into a standard procedure to be offered to industrial partners.