Natural Polymer Modified Starch And Its Application As Glass Fiber Sizing

Glass fiber is an inorganic material with many excellent properties. In recent years, besides traditional industry and agriculture fields, it has been involved in all areas of national production. Due to its high mechanical strength and good corrosion resistance performance, glass fiber is used both in the form of textile products and as reinforcing material in composite materials. Sizing is a critical procedure for the production of glass fiber. The sizing agent can provide temporary protection to the warp yarns from abrasive and other stress generated on the weaving machines, so as to reduce warp damage. It bundles thousands of scattered glass fiber filaments into yarn. The starch based sizing agent has the advantages of good adhesion, low cost, environmental protection, low thermal decomposition temperature and easy removal. Therefore, it has a broad development prospect.In this article, we study on the modification of corn starch and its application in glass fiber sizing. In the research, we used viscosity analyzer(RVA) instrument, surface tension instrument, potential analysis system, SEM, material tester and other test methods, to observe and analyze the surface morphology of precursor fiber sized by modified starch, the tensile strength of monofilament and other properties; the performance of surface tension, viscosity, Zeta potential and so on; compared the performances of glass fibers sized by modified starch, import starch and paraffin.(1)The process of gelatin modified corn starch: When the content of gelatin was 1.0 g, the content of starch was 15.0 g, the reaction time was 1.0 h, the temperature was 90 ?, the content of glutaraldehyde was 0.50 m L, the content of concentrated sulfuric acid was 0.20 m L, the content of polyvinyl alcohol was 0.30 g, under this circumstance, the overall performance of the modified film-forming agent was the best. The viscosity, surface tension and zeta potential of the film-forming agent were 37.99 m Pa·s, 50.40 m N·m-1 and 3.2 m V, respectively. The modified film-forming agent could splice and spread on the surface of glass fiber effectively. Compared with the pristine starch film, the film formed by the modified starch was denser. The glass fiber sized by the modified film-forming agent containing 1.0 g of gelatin had the best mechanical property. The tensile strength reached to 0.49 N·tex-1 and the stiffness was 5.50 cm. The overall performance of the obtained glass fiber yarn was excellent.(2)The process of chitosan modified corn starch: The reaction conditions were optimized via univariate and orthogonal test as follows: corn starch 12.0g, chitosan 0.60 g, reaction time 2.0 h, reaction temperature 90 ?, glutaraldehyde 0.10 m L, gelatin 1.0 g, polyvinyl alcohol 0.30 g, glycerin 1.50 m L, sodium 0.40 g. The surface tension of emulsion was 47.95 m N·m-1, viscosity was 39.68 m Pa·s, contact angle was 16.45°, Zeta potential was 3.2 m V, stiffness was 5.38 cm, tensile strength was 0.51 N·tex-1, area index was 1.140. The results show that the modified product as the film-forming agent in glass fiber sizing could ensure the successful drawing process.(3)The process of KGM modified corn starch: KGM modified corn starch was prepared and applied as film-forming agent in glass fiber sizing. The effect of the KGM content, starch content, the time of reaction and the temperature of reaction on the starch based emulsion, film and sized glass fiber was studied. The viscosity, zeta potential, scanning electron microscope, moisture absorption rate, searing rate and tensile strength were conducted in detail. In the second phase of the optimized test, six sodium phosphate was used as the cross linking agent, and the film property was optimized by the cationic modification of gelatin. The content of gelatin was analyzed by using response surface method, and the content of sodium phosphate in six sodium salt was prepared. The effect of p H on the starch infiltration of the modified corn starch by the cationic starch was analyzed. When the content of KGM was 0.8 g, the content of starch was 12 g, the content of gelatin and sodium hexametaphosphate was 0.75 g and 0.30 g, p H was 8.2, the reaction time was 1h, the temperature was 90 ?, and the overall performance of the modified film-forming agent was the best.Three different methods of modification of film-forming agent, each have advantages, the basic can guarantee the smooth progress of drawing and textile. The experimental study in the future can be based on these three kinds of modification methods of the advantages and disadvantages of the agent.