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Relationship between Spinning Technology and Structure-Property of Polyarylsulphonamide Fiber

Author: WuWanTao
Tutor: WangHuaPing
School: Donghua University
Course: Materials Science
Keywords: Polyarylsulfone amide fiber Structure and properties Rheological behavior Spinning process Ionic liquids
CLC: TQ340.64
Type: Master's thesis
Year: 2010
Downloads: 126
Quote: 0
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Abstract


Polyarylsulfone amide fibers as China has one of the independent intellectual property rights 250 ° C grade high temperature resistant fibers, research on the relationship between its molecular structure, spinning process with fiber structure and performance, and will provide the basis for the preparation of high-performance fibers. Obtain different the polyarylsulfone amide structure, first by changing the monomer ratio of the polymerization reaction by infrared spectroscopy (FTIR), and nuclear magnetic resonance spectroscopy (NMR) analysis, analysis of their chemical structure and molecular sequence structure; ChemSketch Software molecular simulation , calculate the theoretical strength of the different structures of the poly (aryl sulfone) amide fiber; combined thermal gravimetric analysis (TGA), discussed the relationship between the structure and thermal properties of polyarylsulfone amide. The results show that, as between the benzene ring in the molecular structure of the polyarylsulfone amide bit replace part of the increase, despite the theoretical strength of the fibers is reduced, but the workability of the polymer improved thermal stability, almost no change. This indicates that the the polyarylsulfone amide has a wide spinning process window, the balance between the workability as well as product performance can be obtained by changing the composition of its molecule sequence. Anto Paar MCR301 rheometer using the steady state flow characteristics and the dynamic rheological properties of the the polyarylsulfone amide spinning liquid, and by the stability of the spinning solution to the polymer relative viscosity changes. The study showed that the polyarylene sulfone amide is more stable in solution, and does not vary with the dissolution time extension or dissolution temperature increases significant degradation; steady-state study shows that: when the low shear rate, regardless of the solution was apparent viscosity and shear rate, was Newtonian fluid properties; moved to the low rate in the high shear rate region, the solutions exhibit shear-thinning rheological behavior and the critical shear rate increases with the concentration or the temperature decreases, the occurrence of shear thinning. Dynamic rheological studies have shown that: with the increase of solution concentration or temperature decreases, the solution of viscoelastic enhancement gel point does not appear in the experimental range. Meanwhile, the discussed polyarylsulfone amide solubility characteristics of the fiber-forming polymer in the \the polyarylsulfone amide / [Bmim] Cl solution steady state flow and dynamic rheological properties compared with conventional spinning the rheological characteristics. The study showed that: the temperature above 70 ℃ Bmim] Cl polyarylsulfone amide has good dissolving capacity, and as the temperature increases, the dissolution rate is accelerated; polyarylsulfone / amide [Bmim] Cl solution and polyarylene sulfone amide N, N'-dimethyl acetamide (DMAc) was added exhibited similar rheological characteristics, but under the same conditions, zero shear viscosity of greater and greater activation energy of viscous flow. Therefore, it can be achieved by controlling the temperature, concentration, shear rate with conventional spinning liquid phase like the process equipment and process parameters to polyarylsulfone amide / [Bmim] Cl spinning liquid fiber molding and processing. The the polyamide fiber polyarylsulfone supramolecular structure and pore structure along the development and evolution of the spinning process using synchrotron radiation wide-angle X-ray diffraction (WAXD), and small-angle X-ray scattering (SAXS); combined with dynamic thermodynamic (DMA) analysis and thermal gravimetric analysis (TGA) study of the thermal properties of the fibers along the spinning process changes, and along the spinning process paragraphs mechanical properties of the fibers were detected. Studies show that spinning molding process, from the formation of the the polyarylsulfone amide spun fiber, after plastic stretching, washing step, especially in the process of heat stretching and heat setting step, the degree of crystallinity of the fibers, and The degree of orientation of the crystalline region was significantly improved, the interplanar spacing and the grain size of the crystallization zone increases, and along with the increase of the fiber holes; rupture strength and modulus of the fibers with a significant increase in the crystallinity and the increase of the degree of orientation of the crystalline region. By temperature control stretched plastic stretching process, the stretching rate, stretching the impact of temperature on the the the polyarylsulfone amide protofibers drawability, and synchrotron radiation WAXD online monitoring protofibers in tension over the CRYSTALLIZATION state structure changes; draw ratio on the mechanical properties of the fibers. Studies show that in the lower draw rate, the tensile stress with increasing stretching speed is increasing, when the stretching rate reaches 40mm/min, tensile stress occurs on a downward trend, while the l stress - strain curve of high tensile temperature and reduce the tensile rate on the stretching process; fiber fracture strength increased and elongation at break decreased in the the plastic stretching process, as the draw ratio increases, When the stretching ratio is 2.2 times, the orientation of the crystalline region of the fibers have significantly increased, and the best mechanical properties, cause excessive stretching the fiber in the formation of defects, and raw silk interrupt the emergence of the head, so that the mechanical properties of the fibers but decreased. This is closely related to the mechanical properties of the fiber drawing process as well as fiber supramolecular structure to optimize the mechanical properties of the fibers can be effective stretching process.

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CLC: > Industrial Technology > Chemical Industry > The chemical fiber industry > General issues > Production process > Spinning
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