Study Of Producing High-Strength Silk And Polyacrylonitrile Fabrics Grafted By Silkworm Chrysalis Protein

Silk fibers could be acquired by the forced silking of the fifth instars’larval stage Bombyx mori silkworm, and the tensile properties of silk fibers remarkably increased. But these high-strength silk fibers could not be obtained on a large scale with this forcibly silking method.In order to increase crystalline, molecular orientation and the tensile properties of silk fibers, in this paper, the silk fibers were dipped in definite solution, and then they were pulled with a machine. With this method, the high strength silk fibers were produced.An orthogonal test was conducted to investigate optimum conditions, and the pulling ratio of silk fibers increased from 1.3 to 1.7.The dipping solution recipe and pulling conditions of producing high strength silk fibers were optimized:the optimum KSCN concentration was 0.3%, peregal (O) 0.2%, temperature 30℃, and dipping time 40min.The process of producing high strenght silk was:dipping silk fiber in definite solutionâ†'pullingâ†'dryingâ†'removal impurityâ†'drying. The pulled silks were obtained by different forcibly pulling multiple. With raising forcibly pulling ratio, the average diameter and breaking elongation of silk decreased, and the tensile strength increased. The strength of forcibly pulling ratio 1.7 silk fibers increased from 0.45 GPa to 0.78 GPa. It increased by 73.3%.The tensile strength of silk removing impurity increased to1.20 GPa,and it increased by 166.7%. While its breaking elongation was still kept well.The structure of silk fibers were analyzed with infrared spectroscopy, X-ray diffraction and DSC.The results showed that the (3-structure contents, the degree of molecular orientation and decomposition temperature of samples obtained considerably increased when the silk fibers were pulled. The forcibly pulling took important effects on the structure of pulled silk fibers, and the tensile properties of samples remarkably increased.The result showed that high strength silk could be produced with dipping in definite solution and pulling method. The high strength silk fibers have attractive potential in tissue engineering, textile and protection.Polyacrylonitrile fabric has excellent wearability, but as chemical fiber, its biocompatibility is bad for people’s skin. Silkworm chrysalise has rich resource as it is byproduct in reeling silk industry, and silkworm chrysalis protein has desirable bio-capability for people’s skin.Silkworm chrysalis protein was prepared with alkali method, and synthesized a crosslinkage compound sucrose fatty acid ester glycidyl ether (SFEGE) which had softing function. For preparing the grafted fabrics which has excellent wearability and biocompatibility, hydrolysis polyacrylonitrile fabrics were grafted with chrysalis protein by sucrose fatty acid ester glycidyl ether (SFEGE)The surface of the polyacrylonitrile fibers grafted silkworm chrysalis protein was observed by SEM, and the microstructure was analyzed by infrared spectroscopy, X-ray diffraction and DSC. The wearability of the grafted fabrics was measured too. The SEM photo showed that the fiber grafted with chrysalis protein was covered with a layer of membrane; infrared spectroscopy showed that chrysalis protein could be grafed on the polyacrylonitrile fiber. X-ray diffraction revealed that the structure of the fiber grafted with chrysalis protein did not change much; DSC exhibited that the thermal stability of grafted chrysalis protein fiber kept well. The test of wearability indicated that the elasticity, softness and moisture permeability grafted polyacrylonitrile fabrics still kept well, and the hygroscopic property and the air permeability were improved.