Study On Structures Of Male Silk And Its Dyeing Behavor

Current cocoon can only reel male and female composite silk which is difficult to mass-produced high-grade silk because male and female are mixed when drying cocoon, boiling cocoon and reeling cocoon. Male silk has the Male larvae is one of the breed of special variety of Bombyx silkworm. Male silk is one kind of the silkworm Bombyx mori.it has fine cocoon filament size, small evenness variation of cocoon filament, long cocoon filament length, and good reel ability. To our knowledge, currently reports on male silk are not much; the structure and properties of male silk is little studied.The structure and properties of male silk and normal silk were investigated by Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Thermogravimetric and Differential Thermogravimetry Analysis (TG-DTA), single silk strength tester, etc. Moisture of absorption and liberation property of male silk was tested and contrasted. After testing the moisture absorption and liberation regain of male silk in standard atmospheric conditions, moisture absorption and liberation curve were depicted and compared with normal silk. According to the curve, moisture absorption and liberation rate regression equations of the two kinds of silk in standard condition were derivatived. Based on the systematic recognition of property was established. A synthetic evaluation of physical performance of male silk was conducted by means of gray clustering analysis. Cotton, polyester, Model, Tencel, Rayon fiber, Bamboo fiber were taken as objectives. Fracture strength, elastic recovery percentage, moisture regain and mass specific resistance were discussed. In order to understand the principal dyeing performance of male silk completely, the dyeing behaviors of acid dyes and reactive dyes were tested systematically.The results were as follows: The male silk chain possessed group of amide I; amide II, etc. Compared with normal silk, male silk has the higher crystal linity, orientation degree heat resisting property and fracture strength, but the moisture absorption behavior was lower than normal silk. The results of gray clustering analysis evaluation showed that there was great similarity between method of estimating value and interpolation method. Physical performance of male silk was better than cotton and lower than Tencel and Rayon.Results showed that the optimum conditions of male silk dyeing with acid dyes were defined as follows, sodium sulfate 15g/L, pH value 6, raising the temperature from room temperature to 90℃, then keeping at this temperature for 60 minutes. The transfer dyeing properity and desorption properity of male silk were better than normal silk, but K/S value was lower at the same condition. The experimental data showed that Langmuir and Redlich-Peterson were the optimum models which were applied to describe the sorption behavior of acid dyes on male silk. The sorption process was exothermic, Langmuir sorption constant K_L decreased with the rise of dyeing temperature. The interaction force between acid dyes and male silk was electrostatic attraction. A pseudo second-order kinetic model agreed well with the dynamical behaviour for the adsorption of acid dye on male silk under different temperatures. The optimum conditions of male silk dyeing with reactive dyes were defined as follows, sodium sulfate 40g/L, NaHCO₃ 2g/L, raising the temperature from room temperature to 80℃, then keeping at this temperature for 45 minutes. The reactive dyes featured higher dye uptake, as well as satisfactory color fastness. The dye uptake rate and fixation rate for male silk were faster compared to ordinary silk, absorption and fixation in silk took place simultaneously.