【摘要】 通过比较聚丙烯腈(PAN)纤维在空气条件下的热重分析(TG)及不同含氧量气氛中的差示扫描量热分析(DSC)结果,发现氧对PAN纤维有增重及对预氧化环化有促进作用。氧化增重是气氛中的氧对PAN分子链氧化的结果,氧化对PAN分子链螺旋结构的解旋有利于PAN预氧化环化。借助于纤维电子强力仪、显微镜等技术,测定了样品PAN的初始模量、断裂强度及断裂模量。统计结果表明,氧通过参加PAN分子链上的反应,促使PAN分子链的螺旋结构解旋,形成了非螺旋结构,有利于分子内的环化反应,提高了预氧化环化的速度及质量。更多还原

【Abstract】 Through measurements of TG in air and DSC in the different oxygen atmosphere for polyacrylonitrile(PAN) fibers,it is found that PAN fibers are weight gain(oxidation weight gain) and oxygen can promote the pre-oxidized cyclization action of PAN.Oxidation weight gain is the result of PAN reaction with oxygen.The oxidation makes the helix structure of the PAN molecule chain unspooling to the flat structure,which help pre-oxidation cyclization.Through fiber electronic strength tester,microscope and other technologies,the initial modulus,tensile strength and fracture modulus of PAN were determined.The results show that oxygen participates in the PAN chain reaction,causes the helix structure of PAN molecular chains unwinding,forms the non-helical structure,which is beneficial to the intramolecular cyclization reaction,improves the quality of oxidizing silk and final performance of carbon fibers.更多还原