丙烯腈γ辐射聚合的NMR研究

用¹H NMR、¹³C NMR谱、自旋-晶格弛豫时间（T₁）和自旋-自旋弛豫时间（T₂）研究了丙烯腈在⁶⁰Co γ射线辐射聚合后的大分子结构变化与大分子链的运动. 结果表明随着辐射剂量增大，在单体形成聚合物的过程中，聚合物主链上出现了少量的-OH基团，继续增大辐射剂量， -OH部分被氧化. 对聚合物溶液的变温氢谱的研究表明，溶剂中的残余水与上述-OH形成氢键，且随着温度升高氢键被破坏，同时H₂O与-OH之间还存在着质子交换. 利用¹³C NMR谱对丙烯腈辐射聚合的产物进行了序列结构分析. 对T₁和T₂的研究表明，辐射剂量的增大并未影响到聚丙烯腈的链运动，证明了在丙烯腈的辐射聚合过程交联反应未发生.

60Co γ Irradiation Induced Polymerization of Acrylonitrile Studied by NMR Spectroscopy

⁶⁰Co γ irradiation induced polymerization of acrylinitrile (AN) was studied by ¹H and ¹³C NMR spectroscopy. The results show that the signal intensities of AN monomer peaks decrease after irradiation, and this is accompanied by the appearance of a polymer peak, whose signal intensity increases with the irradiation dose. The sequence distribution of polyacrylonitrile was assigned using ¹³C NMR data. The results of variable temperature experiments indicate that there exist hydrogen bonds, as well as proton exchange, between residual water and the -OH group on the polymer. Relaxation time measurements show that the motion of polymer segments is not influenced significantly by the increase of irradiation dose.