Wet spinning of silk polymer

Wet spinning of Bombyx mori silk fibroin dissolved in N-methyl morpholine N-oxide and properties of regenerated fibres

“…This suggests that crystallization of SF to Silk II structure occurred almost entirely during the coagulation process and that it was independent on drawing or, at least, it was not significantly influenced by drawing within the range of draw ratio examined. Similar results were reported for regenerated SF fibres obtained by a wet spinning process using formic acid as solvent and methanol as coagulating agent [18]. Another interesting IR feature is the behaviour of the full-width at half-maximum (FWHM) of the amide I band at 1622 cm −1 , which decreased exponentially as a function of the draw ratio (Fig.…”

“…However, the extremely high cost of these solvents has prevented any further scale-up for a possible industrialization of the spinning process. More recently, results obtained from spinning SF in formic acid were reported by Park et al [18] and Hudson et al [19], who particularly focused on the role of the processing technique on fibre properties. "As spun" fibres were drawn by hand in a wet state, after 4 h of residence in a coagulation bath, and fibres with very interesting properties were obtained, i.e.…”

Characterization of chemically treated bacterial (Acetobacter xylinum) biopolymer: Some thermo-mechanical properties

“…In the case of chemically treated membranes, only one peak was noticed between 350.95 • C and 355.8 • C (Table 2), indicating an effective removal of proteinaceous matter and other media ingredients by the alkali treatment. It was also found that after alkali treatments, the T max of the cellulose membranes increased by about 40 • C. Since thermal degradation behaviour is affected by the structural parameters such as molecular weight, crystallinity and orientation, these variables should be explained in a cohesive manner while discussing the improved thermal stability [18]. Due to chemical treatments at higher temperatures (100 • C), low molecular weight impurities were removed causing variation in crystallinity and orientation of cellulose fibrils.…”

Effect of shearing on formation of silk fibers from regenerated Bombyx mori silk fibroin aqueous solution

“…A number of groups have attempted to spin silk fibers from regenerated silk fibroin (RSF) solution or recombinant spidroin solution. In these works, some organic solvents were used to form the dope, such as hexafluoro-2-propanol and formic acid, etc., and methanol or acetone was used as coagulation bath [7][8][9][10][11][12][13]. In contrast to hazardous solvents and harsh conditions needed to produce aramid fibers, in natural, however, spider silk and silkworm silk are spun into air at ambient temperature and using water as the solvent.…”