Study On Wet Spinning Properties Of Regenerated Collagen Fiber Based On Microfiber Structure

In recent years,with the continuous development of the textile industry,clothing textiles with characteristics of multi-functional,high-quality and pollution-free have gradually become the favored object of people.The regenerated fiber products represented by regenerated collagen fiber stand out with their excellent performance.Regenerated collagen fiber has many advantages,such as wide source,comfortable skin,bacteriostasis and environmental protection,which regards as a prospective candidate in the textile fiber field.However,due to the special structures of collagen,it has some disadvantages,such as poor solubility of raw materials,poor spinnability and narrow processing window.At the same time,regenerated collagen fiber has shortcomings in mechanical properties,water resistance and thermal stability,resulting in difficulties in the industrial production.It has become one of the most important obstacles for regenerated collagen fiber to come onto the clothing textile market.Therefore,it is of significance to develop a kind of simple fiber forming technology that are suitable for industrial production.This technology is expected to improve spinnability of collagen,fiber mechanical properties,water resistance and thermal stability,giving full play to the excellent natural properties of collagen.It has far-reaching significance for the development of collagen fiber and downstream products.On the basis of studying the spinnability of collagen spinning solution,aiming at improving the mechanical strength,water resistance and thermal stability of collagen fiber,this paper selects deionized water as diluent and hydrochloric acid to adjust the pH value.The regenerated collagen fiber with internal microfibril reinforcement structure is prepared via wet spinning technology.Furthermore,glutaraldehyde crosslinking method was used to improve the mechanical properties,water resistance and thermal stability of the fiber,while the effects of different crosslinking methods on the properties of the fiber were studied.The main contents and results of this paper are as follows :In order to improve the spinnability,the stability of collagen spinning solution at different pH was studied.Meanwhile,the effects of concentration,temperature and swelling time on its rheological properties were explored,so as to determine the best preparation parameters of the spinning solution.The characterizations,such as scanning electron microscopy,infrared spectroscopy and circular dichroism,indicated that the prepared collagen spinning solution had a complete basic structure of collagen.To further improve the poor mechanical properties of the primary fibers,the regenerated collagen fibers were prepared by wet spinning.The effects of spinning concentration,coagulation bath parameters,spinneret draw ratio on the mechanical properties,orientation and micro morphology of the regenerated collagen fibers were investigated.The results showed that the regenerated collagen fiber had the best mechanical properties and compact structure with the optimal spinning conditions,including the solution concentration of 1.4 wt%,coagulation bath of PFG-20000 with a concentration of 20 wt%,pH of 13,coagulation bath length of 70 cm and spinneret draw ratio of 2.25.The microfiber had the characteristics of highly oriented arrangement along the long axis of fibers.Its breaking strength could reach 1.07 cN/dtex and orientation degree was 89.7%.Furthermore,to improve the mechanical properties,water resistance and thermal stability of collagen fibers,four different glutaraldehyde crosslinking methods were utilized to treat nascent collagen fibers,in which the properties of water bath crosslinked and in-situ crosslinked fibers were enhanced to varying degrees.In terms of mechanical properties,the dry breaking strength increased by 45.8%,reaching 1.56 cN/dtex,while the wet breaking strength increased by 167.3%,reaching1.31 cN/dtex.These dry and wet strengths were better than those of wool.Moreover,the water absorption of fiber decreased by 71.3%,reaching to 136%;the thermal denaturation temperature increased by 62.8%,reaching to 101.1?.In conclusion,the collagen fiber with microfibril oriented structure was obtained by wet spinning combined with glutaraldehyde crosslinking technology.The fiber had the good mechanical properties,water resistance and thermal stability,basically meeting the requirements of textile fiber.It indicated that it had a certain application prospect and commercial value in the field of textile and clothing,laying a foundation for the industrial development of subsequent products.