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This selection of acrylamide (AM) as the second monomer, itaconic acid (IA) of the third monomer, the alkali metal ions of ammonium persulfate (APS) as initiator, to the aqueous phase to precipitate the synthesis of high-performance carbon fibers poly-acrylonitrile (PAN). By the polymerization reaction temperature, time, pH, initiation system, comonomer concentration, and the chain transfer agent and terminating agent to determine the optimum reaction conditions. Using Fourier transform infrared spectroscopy (FTIR), elemental analysis instrument (EA), X-ray diffraction the Miriam (XRD), differential scanning calorimetry the Miriam (DSC) and thermal gravimetric analysis (TG), nuclear magnetic resonance (NMR), R / SCC coaxial cylinder rheometer test instruments and methods copolymer AN / AM competitiveness reactivity ratio, molecular chain structure, thermal and rheological behavior discussed comonomer PAN performance and the spinning solution impact. The findings of this study system optimal reaction conditions: temperature of 60-65 ° C, the reaction time of 2 h, initiator concentration of 0.8wt% AM control within 2wt%, IA terpolymer is less than 1 wt%; composite initiator system should be selected (AS), ammonium sulfite as a reducing agent, APS with AS the molar ratio should be between 2:1 to 1:1; chain transfer agent with ethanolamine (EOA); N, N-di diethylhydroxylamine (DEHA) as efficiently terminating agent is used in this system, the amount of 2 wt ‰ in the total monomer mass. By controlling the above reaction conditions to obtain a high conversion rate and different molecular weight of the copolymer. By elemental analysis, reactivity rate was calculated AN / AM KT method: rAN = .9028 rAM = 1.397, the the YBR method of results:-N = .9043 rAM = 1.410. AN segment sequence length by feeding the content of AM, AM content of the copolymer properties. AM and IA introduction may be respectively formed in the infrared spectrum amide and the carboxyl group of the C = O stretching vibrations. On 13C-NMR spectra calculated by the three-unit structure the proportion of of miscellaneous isotactic the molecular chain of about 50%, and the introduction of AM and IA will make the copolymer regular degree decreases slightly. Presents the trend first and then decreased with the the AM amount of the increase, the degree of crystallinity, and grain size has been reduce; IA will lower copolymer crystallinity and grain size, and the remarkable reduction. Copolymers, DSC, TG, FTIR and test analysis results show that the AM and IA makes copolymer exothermic reaction in advance, and in the formation of bimodal and trimodal DSC curves, the exothermic peak width, weight loss to reduce and slow down exothermic reaction, improve the performance of the original wire, IA lowering effect. Copolymer in the air some of the main absorption peaks in the pre-oxidation process, C ≡ N, and CH2 weakened gradually and disappear, and the stretching vibration of C = C and C = n group gradually appeared and enhanced, while in the copolymer C ≡ N reduction rate is significantly higher than the homopolymer. PAN dope rheological properties of the studies show that with a solids content of the copolymer and the molecular weight increased, the viscosity of the solution becomes large, the degree of structure to improve the non-Newtonian enhanced physical stability deteriorates, the non-Newtonian index decreased . P (AN-co-AM) copolymer, molecular weight greater impact copolymer Thermosensitive presented in the lower molecular weight, molecular weight increased more sensitive to shear stress. The order of the size of the dissolving ability of the three solvents of PAN copolymers of dimethyl formamide (DMF) GT; dimethylacetamide (DMAC) GT; dimethyl sulfoxide (DMSO), and the temperature sensitivity of the opposite . P (AN-co-AM) copolymer solution, molecular weight should be around 200,000, the spinning temperature of 353K, rather the solvent should use DMAc.
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