The Study Of Free Radical Polymerization Of Acrylonitrile Under Magnetic Field And Its Product Performance

To produce high-performance polyacrylonitrile(PAN)-based carbon fiber,it is essential to produce high quality polyacrylonitrile precursor,and to get high-quality polyacrylonitrile precursor,high-quality polyacrylonitrile polymer is needed.High-quality polyacrylonitrile generally need to have high purity,high average molecular weight,narrow relative molecular weight distribution and high regularity of the molecular structure and so on.Given that several traditioal methods of produce PAN nowadays can not measure efficacy with quality,also,with the developement of technology,equipment with high magnetic will be easy using in chemical reaction study.This paper aim to explore a new efficient method for the preparation of quality polyacrylonitrile,through a series of free radical polymerization of polyacrylonitrile in different magnetic filds,and the high magnetic fild effect of these reaction in different magnetic filds was studied systematically,also,the PAN raw fibers were synthesized and analysed.13CNMR,FTIR,GPC,XRD,TG and DSC was used to verify its structure and properties.The results showed that the preparation efficiency of PAN was higher under 9 T strong magnetic field,The yield is increased from 41.7% under the condition of 0 T magnetic field to 63% under 9 T magnetic field condition,and the PAN structure prepared under the condition of 9 T magnetic field is more excellent,and the isotactic content is increased from 25 % of 0 T magnetic field to 43 % of 9 T magnetic field,the number average molecular weight is increased from 8.44(�105)to11.63(�105),and crystal and thermal properties of the PAN prepared under 9 T magnetic field conditions has more excellent.Also,the two kinds of PANs obtained under the condition of 9 T(strong magnetic field)and 0 T(no magnetic field)were synthesized,the structure and properties of these two polyacrylonitrile raw fibers were studied.It was shown that the spinnability of the obtained PAN under the strong magnetic field and the structure and mechanical properties of the corresponding precursor are better than those obtained when the magnetic field is not obtained.The results show that the protrusions prepared by PAN without magnetic field are obtained by elemental analysis,crystallization analysis and structural analysis of these two kinds of preoxidized raw silk fibers(0 T,9 T).The preoxidation of the precursor prepared byPAN under the magnetic field conditions is easier and the preoxidation is more complete,showing better preoxidation.