Heat-treatment Of The Dry-wet Spun Fibers From Regenerated Silk Fibroin Solution

Tussah silk has been noted for its excellent property. But the waste came fromproduction is serious. Regenerated silk fibroin fibers realized the fiber-regeneration ofabandoned silk fibroin which obtained by using dry-wet spinning technology, while theproperties and structure of the fibers were imperfect, post-treatment of dryingdensification and draw in stream on the RSF as-spun fibers was studied to improve theproperties and structure of RSF fibers. This paper made a study of the process andmechanism of the post-treatment. The shrinkage, mechanical properties, thermalproperties of RSF fibers made in various drying densification conditions, includingtemperature, humidity ratio and methods were tested and their structure were analyzedwith the help of polarizing microscope, scanning electron microscopy and X-raydiffraction. The results showed that the diameter and boiling water shrinkage ratio, breakstrength, thermo stability of RSF fibers obtained under the condition of temperature is120℃, humidity is60%has been improved, which also with homogenous and densestructure, decreased orientation degree. The state of the RSF fibers had great effect ontheir structure and properties. The shrinkage, break strength of RSF fibers were improvedafter the tension drying densification, while the dimensional stability and the TG weredecreased. The impacts of the draw down ratio in steam on the structure and properties ofRSF fibers were studied. The dimensional stability, mechanical property and thermalproperty of different ratio were studied by the test of boiling shrinkage, break strengthand TG which were improved with the increase of the draw in steam ratio. The structure of RSF fibers were characterized by polarizing microscope, X-ray diffraction and infraredspectra, which showed that parts of Silk Ⅰ transformed into Silk Ⅱ and the orientationwas enhanced with the increase of the draw ratio.