Wet-spun blend biofibers of cellulose-silk fibroin and cellulose-chitin-silk fibroin

Each spinning solution of silk fibroin-sodium cellulose xanthate (viscose) in aqueous NaOH, and silk fibroin-viscose-sodium N-acetylchitosan salt (alkaline chitin) in aqueous NaOH was spun at room temperature through a spinneret (0.1 mm in hole diameter) into a 10% aqueous sulfuric acid solution containing 40-43% ammonium sulfate. Novel white blend biofilaments were obtained in over 95% yield. The cellulose-silk fibroin filaments containing less than 10% silk fibroin had 4.9-9.9 denier for the titer value, 1.08-1.20 g/denier for the tenacity value and 29.7-35.0% for the elongation value. The cellulose-chitin-silk fibroin filaments containing less than 43% silk fibroin had 3.9-5.0 denier for the titer value, 0.70-0.93 g/denier for the tenacity value and 20.6-28.6% for the elongation value. (C) 2002 Elsevier Science Ltd. All rights reserved.