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The introduction of other monomers of acrylonitrile copolymerized modified by changes in the composition and structure to alter the thermal properties of polyacrylonitrile, acrylonitrile polymer becomes possible to melt completely non-meltable. Experimental part mainly includes three parts: ⑴ acrylonitrile (AN), methyl acrylate (MA) and acrylic acid (AA) terpolymer; ⑵ AN and MA binary copolymer; ⑶ polymer electrospinning. AN, MA and AA terpolymer, using water as the reaction medium, to potassium persulfate (KSP) and sodium bisulfite (SBS) as the initiator, explore monomer ratio, reaction temperature, monomer concentration and initiator content polymerization. Because it is a ternary reaction, and the value of AA on the pH of the reaction system impact, the influence of the ratio of monomers discussed more complicated, the the AA proportion of content of the polymerization reaction. In the case of other conditions remain unchanged, the content of the monomer concentration and initiator increases, the reaction speed, a short time to achieve high conversion rates, and therefore both the content is not too high, to avoid polymerization excessive insecurity . Reaction temperature influence on the polymerization reaction, 60 ℃ dramatic implosion in caking; temperature is below 40 ° C, the conversion rate is too low, can not even polymerization. AN and MA binary copolymer, water and dimethyl formamide / water (DMF/H2O) two reaction medium, to potassium persulfate (KSP) and sodium bisulfite (SBS) as the initiator and isopropanol as chain transfer agent, respectively, the monomer ratio, reaction temperature, monomer concentration, initiator content, the influence of the reaction medium composition and the chain transfer agent is used in an amount on the reaction process and the polymerization product. Indicators investigated by viscosity average molecular weight of the polymer product, conversion rate, and the use of infrared spectroscopy (FTIR), DSC analysis and microscopic morphology analysis means analysis and discussion of the structure and properties of the product. The experiment found that the greater impact, the specific performance of reaction temperature on the reaction process: the reaction temperature is high, the polymerization reaction is rapid, even explosive polymerization reaction is too severe and; reaction temperature is low, the polymerization reaction proceeds slowly, do not even occur polymerization. Monomer ratio, monomer concentration, initiator content of the reaction medium and chain transfer agent major impact on the structure and properties of polymer products. By adjusting the experimental parameters, you can make the reaction process of security and stability, and acrylonitrile copolymer melt. The best experimental conditions were: reaction temperature between 40 ~ 45 ℃ monomer ratio AN / MA 85/15 to 90/10, the monomer concentration in the range of 20% to 25%, potassium persulfate content accounting monomer content 0.3 wt% sodium bisulfite content accounting for the amount of monomer, 2 wt%, reaction medium composition H2O/DMF was 90/10, the amount of monomer of the chain transfer agent is used in an amount of 4 wt%. Finally, the resulting polymerization product was dissolved in dimethylformamide (DMF), spinning was conducted using an electrostatic spinning method, explore the electrostatic spinning process and polymer spinnability. The results showed that at a polymer concentration of 8 to 10%, an applied voltage of 15 kV, to obtain polyacrylonitrile fiber mat.
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