The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Swedish Pulp and Paper Research Institute, Box 5604, SE-114 86 Stockholm, Sweden Department of Physical Chemistry, University of Uppsala, SE-751 21 Uppsala, Sweden Arrhenius Laboratory, Department of Analytical Chemistry, University of Stockholm, SE-106 91 Stockholm, SwedenHardwood kraft pulps can be completely dissolved in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc). The cellulose and hemicellulose components can be separated by size exclusion chromatography (SEC). The molecular weight distribution that corresponds to cellulose is extended up to the high molecular weight region and the weight average molecular weight (Mw) relative to pullulan of this distribution is high. Light scattering (LS) measurements were conducted on a cotton linters sample of a similar elution volume as the cellulose portion of the pulp. The true Mw of the cotton linters sample measured by LS was in close agreement with the Mw determined relative to pullulan using SEC. Gaussian curve fitting revealed an additional high molecular weight component, not apparent in the chromatogram of hardwood pulp. Based on this finding the high Mw is suggested to be due to aggregation of cellulose in LiCl/DMAc. The influence of dissolution conditions is discussed and a method for deaggregating the cellulose portion of dissolved hardwood pulps is proposed.Cellulose aggregationLithium chloride/N,N-dimethylacetamideSize exclusion chromatography
Swedish Pulp and Paper Research Institute, Box 5604, SE-114 86 Stockholm, Sweden Department of Physical Chemistry, University of Uppsala, SE-751 21 Uppsala, Sweden Arrhenius Laboratory, Department of Analytical Chemistry, University of Stockholm, SE-106 91 Stockholm, SwedenHardwood kraft pulps can be completely dissolved in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc). The cellulose and hemicellulose components can be separated by size exclusion chromatography (SEC). The molecular weight distribution that corresponds to cellulose is extended up to the high molecular weight region and the weight average molecular weight (Mw) relative to pullulan of this distribution is high. Light scattering (LS) measurements were conducted on a cotton linters sample of a similar elution volume as the cellulose portion of the pulp. The true Mw of the cotton linters sample measured by LS was in close agreement with the Mw determined relative to pullulan using SEC. Gaussian curve fitting revealed an additional high molecular weight component, not apparent in the chromatogram of hardwood pulp. Based on this finding the high Mw is suggested to be due to aggregation of cellulose in LiCl/DMAc. The influence of dissolution conditions is discussed and a method for deaggregating the cellulose portion of dissolved hardwood pulps is proposed.Cellulose aggregationLithium chloride/N,N-dimethylacetamideSize exclusion chromatography
Swedish Pulp and Paper Research Institute, Box 5604, SE-114 86 Stockholm, Sweden Department of Physical Chemistry, University of Uppsala, SE-751 21 Uppsala, Sweden Arrhenius Laboratory, Department of Analytical Chemistry, University of Stockholm, SE-106 91 Stockholm, SwedenHardwood kraft pulps can be completely dissolved in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc). The cellulose and hemicellulose components can be separated by size exclusion chromatography (SEC). The molecular weight distribution that corresponds to cellulose is extended up to the high molecular weight region and the weight average molecular weight (Mw) relative to pullulan of this distribution is high. Light scattering (LS) measurements were conducted on a cotton linters sample of a similar elution volume as the cellulose portion of the pulp. The true Mw of the cotton linters sample measured by LS was in close agreement with the Mw determined relative to pullulan using SEC. Gaussian curve fitting revealed an additional high molecular weight component, not apparent in the chromatogram of hardwood pulp. Based on this finding the high Mw is suggested to be due to aggregation of cellulose in LiCl/DMAc. The influence of dissolution conditions is discussed and a method for deaggregating the cellulose portion of dissolved hardwood pulps is proposed.Cellulose aggregationLithium chloride/N,N-dimethylacetamideSize exclusion chromatography