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Method development for rheological characterization of microfibrillated cellulose / Utveckling av en metod för reologisk karakterisering av mikrofibrillerad cellulosa

This thesis contributes to a development of a method for rheological characterization of microfibrillated cellulose. The intended use of the method is to be able to distinguish between different grades of microfibrillated cellulose. The method that was developed had preparation procedure of suspensions, pH, dry content and conductivity as well as measuring geometry and measuring sequence in mind. The method resulted in using a propeller mixer for sample preparation and the most suitable properties of the samples for comparison of different qualities of microfibrillated cellulose was evaluated to be pH 8 with a dry content of 2.0 wt% and a conductivity of 110 µS/cm. The rheology of the microfibrillated cellulose suspensions was examined by using a dynamic rotational rheometer and a splined bob and cup (C25G/PC25G). The complex viscosity from amplitude sweeps is used as the parameter to distinguish between different grades of 2 wt% microfibrillated cellulose suspensions. At 1.0 wt% the pH of the suspensions appeared to have a very small impact on the results from rheological measurements while an increased conductivity of the suspensions resulted in an increased complex viscosity. The dry content dependency appeared to be exponential in the range of 0.5 to 3.0 wt% and it was thus easier to distinguish between different grades of microfibrillated cellulose when the dry content is 2.0 wt% compared to 1.0 or 1.5 wt%.

Identiferoai:union.ndltd.org:UPSALLA1/oai:DiVA.org:kau-78968
Date January 2020
CreatorsWahlkrantz, Elin
PublisherKarlstads universitet
Source SetsDiVA Archive at Upsalla University
LanguageEnglish
Detected LanguageEnglish
TypeStudent thesis, info:eu-repo/semantics/bachelorThesis, text
Formatapplication/pdf
Rightsinfo:eu-repo/semantics/openAccess

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