|
POM is a high-density, high crystallinity linear polymer, with excellent overall performance. With its preparation POM POM fiber can inherit most of the advantages and can play to their potential advantages of high strength, high modulus and excellent dimensional stability, thermal stability and alkali resistance, chemical resistance, light resistance, weatherability , abrasion and other properties, is one of the best overall performance synthetic fibers, has good application prospects. POM preparation of a variety of fibers, melt spinning method so far is to reduce production costs, improve production efficiency, the best way to achieve industrial production. However, POM high crystallinity, the crystallization rate is fast and the melting point and decomposition temperature close POM spun fiber is likely to cause uneven structure, which affects the mechanical properties of the finished fibers and thermal properties, a stable production and improve fiber performance bottlenecks. Therefore, melt-spinning process of POM and drawing technology, to achieve the industrial production of fiber POM significance. This topic has been sliced ??on POM thermal, rheological properties of POM slice analysis and thermal decomposition kinetics; explored POM fiber melt spinning and drawing process water bath to study the crystallization properties of POM fibers, orientation structure, mechanical properties and acid and alkali resistance. POM slices used in the experiment melting point of 162.03 ℃, melt index 9g/10min. Found, POM thermal decomposition reaction is first decomposition activation energy E = 367.87kJ/mol, below 230 ℃, the thermal decomposition rate of less than 0.02% / min; POM melt non-Newtonian fluid, the melt temperature from 190 ℃ increased to 230 ℃, POM non-Newtonian index increased 0.53 to 0.61, macromolecular chains capacity enhancement activities. In the same shear rate, the apparent viscosity decreases with increasing temperature; shear rate of 90-2500s-1 range of changes, POM activation energy of viscous flow distribution 11.36-24.90kJ/mol range. In this study, a twin-screw melt spinning machine spinning POM spun fibers, obtained using the method of drawing water bath POM fibers. As fast heat transfer medium has a water bath, heat capacity, temperature fluctuations of small features, while the presence of water molecules play the role of plasticized, the internal stress of the fiber can be reduced, so that relative sliding between the molecular chains becomes easy, the fiber is stretched greatly reduce internal defects to stabilize production and improve the performance of the fiber. As the bath temperature, POM fiber crystallinity, the maximum draw ratio increases; with the increase of draw ratio, POM fiber orientation degree, tensile strength, initial modulus increases, elongation at break less small. POM experiment obtained maximum tensile strength of the fibers 7.44cN/dtex, the maximum Young's modulus of 54.04cN/dtex, the minimum elongation at break of 15.00%.
|