157 FIBRES & TEXTILES in Eastern Europe January / December 2007, Vol. 15, No. 5 - 6 (64 - 65) n Introduction The strive to use less popular biopoly- mers, has, amongst other, increased interest in feather-derived keratin. Vig- orous expansion in the manufacture of pharmaceutical and sanitary products has fostered a market demand for textile materials which manifest specifc fea- tures like the ability to absorb and retain humidity. The keratin contained in feath- ers seems to be a promising candidate as raw material in the preparation of composite hygiene products. Many publications identify innovative products, which include feather fber keratin in their compositions [1 - 7]. The aim of our research work was to ob- tain different fbrous forms, such as fbres and fbrids, with a content of keratin ex- tracted from chicken feathers. We chose cellulose already used to manufacture biocomposites for medical and hygiene applications as the second component. An assumption was made that by using the hydrophilic properties of keratin, the application of this biopolymer should result in the manufacture of fbrous com- posite materials with increased sorption properties. The investigations included: n preparing stable keratin solutions with an addition of cellulose, n estimating the properties of the com- posites obtained. n Materials and reagents Keratin The raw material for obtaining keratin came from chicken feathers, which were characterised by the following contents: n a sulphur content of 2.9%, n a nitrogen content of 15.5%, n an ash content of about 1%. The method of obtaining keratin from chicken feathers is described in [8], whereas the properties of the keratin we used in this research are presented below: n a sulphur content of 2.3%, n a nitrogen content of 15.2%, n a cystein content of 16,94 % n a WRV of 155.5 % n a sorption factor 188.5% n an Mw of 144.6 kDa n an Mw/Mn of 2.6 n colour, shape white powder. Biomodifed cellulose The cellulose pulp used for obtaining biomodifed cellulose is characterised by an polymerisation degree of DP = 670. A commercial enzymatic preparation produced by AB Enzymes Oy (Finland) under the trade name of Econase CE was used as the bio-modifying agent. The properties of the biomodifed cellu- lose we used in this research are pre- sented below: n Solubility of cellulose Sa 99.7% n Content of α-cellulose α cel 93.9% n Water retention value WRV 78.0% n Average polymerisation degree DP 349.0. The biomodifcation process is described in more detail in the European Pat- ent [9]. The chemical agents used for obtaining the keratin were of analytical purity. n Methodology Preparing biomodifed cellulose spinning solution The solution prepared was used for tests consisting of the formation of cellulose fbres and flms [10]. To prepare an al- kaline spinning solution, a biomodifed cellulose pulp containing 75% of water is put into a 10.2% aqueous solution of sodium hydroxide, which also contains zinc oxide, urea and surfactants. The biomodifed pulp is dissolved in a mixing tank equipped with a high-speed agitator and cooling jacket. The process is com- pleted over 30 minutes at a temperature rising from 0 to 13 °C. The spinning solution obtained is fltered on a frame press through a standard flter cloth, as used in the viscose fbre industry, and then deaerated. Preparing cellulose-keratin spinning solutions for fbres Cellulose-keratin solutions were prepared by mixing the fltered and aerated alkali (6.24%) biomodifed cellulose solution with an alkali keratin suspension. Alkali keratin solutions with different concen- tration within the range from 5% to 20% were also prepared. The keratin suspen- sion was mixed with different ratios of the biomodifed cellulose spinning solu- tions. In order to perform this, a keratin Novel Biocomposites with Feather Keratin Krystyna Wrześniewska-Tosik, Dariusz Wawro, Maria Ratajska, Włodzimierz Stęplewski Institute of Biopolymers and Chemical Fibres, ul. M. Skłodowskiej-Curie 19/27, 90-570 Łódź, Poland Abstract This work deals with the preparation and characterisation of cellulose-keratin biocompos- ites. A method of manufacturing fbrous composite materials by wet spinning is presented. We used natural polymers, biomodifed cellulose and keratin obtained from chicken feath- ers. Keratin waste is a potential renewable starting material. Spinning solutions were prepared from these polymers, and after fltration and aeration they were used for the for- mation of fbres and fbrids . The investigations included the preparation of biomodifed cel- lulose-keratin spinning solutions of different keratin content, estimation of the infuences of formation speed and drawing on the fbre properties, estimation of the sorption properties of the composites obtained. The biomodifed cellulose-keratin fbres obtained are charac- terised by better sorption properties, higher hygroscopicity and smaller wetting angle, than those of cellulose fbres. The introduction of keratin into cellulose fbres lowered their me- chanical properties, but they reach a level which enables the application of these fbres for manufacturing composite fbrous materials. Composting tests, carried out at 50 0 C, showed the better biodegradability of composite fbres than that of cellulose fbres. The biomodi- fed cellulose-keratin fbrids are also characterised by better sorption properties than those of cellulose fbrids. As a result of the lyophilisation of composite fbrids cellulose-keratin sponges were obtained. Key words: keratin, biomodifed cellulose, composite fbres, fbrids, sponge, biodegradation.