Bio-R: Applications for treating Cellulosic bodies with supercritical carbon dioxide
The project has been aborted due to a lack of success. The water absorbance of cellulose fibres (Lyocell), which were produced according to the amine oxide method, has not increased considerably by means of supercritical dehydration. Because of the expected high operational costs and the necessary substitution of the dissolver it was not possible to ensure profitability. Furthermore the utilisation of an organic dissolver would not fulfil the principles of the subprogramme "Factory of Tomorrow".
An optimal selection of the dehydration conditions could possibly adjust the size of the pores of the fibre in a way that enables a specific disposal of the agent. However, in that case the substances which are pharmacologically interesting should be well known, so it would be necessary to cooperate with a pharma company.
The target of this project is the screening of the opportunities, resulting from the combination of treating Cellulosic bodies with supercritical carbon dioxide. The main focus is the investigation of incorporation opportunities of active substances within Cellulosic fibres, e.g. produced with the NMMO process. It is likely to increase the number of incomparable compounds in an environmental friendly way by using the technique of supercritical fluids. The usage of supercritical carbon dioxide may open a door for compounds which are not usable by classical incorporation technologies. D-Panthenol, Tocopherol and Tocopherolacetate were selected as model compounds. The incorporation of D-Panthenol was successful over the cross section of a Cellulosic fibre. It was also possible to incorporate Tocopherolacetate. Contrary to these results the trials with Tocopherol were not successful.
Alternatively the tested compounds (D-Panthenol and Tocopherolacetate) could be deposited on fibres by use of the simple spray on technique, but the distribution of the active compound is inhomogeneous. With the help of micro capsules we were successful to load Tocopherol on Lyocell fibres. Because the incorporated active compounds are easily removed by a single washing step, these fibres are only useful for single use applications. This behaviour is independent from the way of incorporation.
A low release effect could be observed for the incorporated compounds D-Panthenol and Tocopherol. No slow release effect could be observed in case of Tocopherolacetate.
Dr. Gregor Kraft
Werkstraße 2, 4860 Lenzing
Tel.: +43 (7672) 701 - 3099
Fax: +43 (7672) 701 - 3099