磁场对聚苯胺结构、掺杂行为及热稳定性的影响

在恒定磁场(0.8T) 和无磁场环境下,采用化学氧化聚合法合成了分别用磺基水杨酸(SSA)、对甲基苯磺酸(TSA)以及用十二烷基苯磺钠/盐酸(SDBS HCl)掺杂的聚苯胺盐,并采用X射线光电子能谱(XPS)、傅立叶红外光谱(FT-IR)、X粉末衍射(XRD),热重分析(TGA)等手段研究了磁场对聚苯胺结构、掺杂行为及热稳定性的影响.结果表明在合成聚苯胺的过程中,作为表面活性剂的十二烷基苯磺酸钠在无机酸存在条件下转变成十二烷基苯磺酸并与无机酸共同掺杂进入聚苯胺链;磁场环境下合成的聚苯胺盐比无磁场下合成的聚苯胺盐的链更加规整,热稳定性更好,掺杂程度以及结晶性能也有所提高;从红外光谱分析中可知,磁场取向作用使分子链更加伸展,分子链离域程度更大,但磁场没有明显地改变聚苯胺的基本单元结构.     

磁场(0.8T)环境中聚苯胺宏观掺杂动力学行为探讨

在恒定磁场(0.8T)环境下,采用乳液法合成复合磺酸掺杂聚苯胺(PAn),探讨了PAn的掺杂机理,并对聚合过程中PAn的宏观掺杂动力学行为进行了研究.研究结果表明:外加磁场能明显提高苯胺聚合的反应速率,其取向作用能使PAn分子链更加伸展,有利于掺杂以及分子链的增长,具有更快的掺杂速率、更高的掺杂程度、特性粘度和溶解率,且掺杂主要发生在反应初始阶段.粒径分析结果表明磁场环境下合成的PAn粒子其粒径更小,分布更窄.     

Effect of magnetic field on property and structure of polyaniline doped with multiple sulfonic acids

Polyaniline（PAn） doped with multiple sulfonic acid system of dodecylbenzenesulfonic acid（DBSA） and sulfosalicylic acid（SSA） was synthesized by emulsion polymerization using ammonium persulfate（APS） as an oxidizing agent in the presence and the absence of a constant magnetic field（MF）of 0.8 T. The structure and properties of the PAn were characterized by X-ray diffractometer（XRD）, thermogravimetric apparatus（TGA）, FT-IR spectroscope（FT-IR） and four probe digital multimeter. The results indicate that, when the molar ratio of DBSA to SSA is 1/3, that of dopant to An is 3/2, that of APS to An is 4/5 in the synthesizing media, and the doping time is 3 h, the conductivity of the PAn synthesized in the presence of the MF of 0.8 T reaches 5.88 S/cm, which is higher than that of the PAn synthesized in the absence of the MF. The thermal stability, the crystallinity and the doping degree of the PAn synthesized in the presence of the MF are also improved. MF not only enhances the conductivity, but also reduces the doping time, the dosage of the dopant and the oxidizing agent when the conductivity reaches the maximum.