溶液缩聚法合成聚苯并咪唑及其静电纺丝研究

Synthesis of polybenzimidazole by solution polycondensation and its electrospinning

以N,N-二甲基乙酰胺为溶剂,通过溶液缩聚法合成聚苯并咪唑(PBI),并利用静电纺丝法制备PBI纳米纤维;研究了间苯二甲醛/亚硫酸氢钠摩尔比对间苯二甲醛亚硫酸氢盐加合物(IBA)纯度的影响、单体(IBA和3,3′-二氨基联苯胺)浓度对PBI比浓对数黏度(η_(inh))的影响,以及静电纺丝工艺参数(溶液浓度、电压和推进速度)对PBI纳米纤维形貌的影响。结果表明:当间苯二甲醛/亚硫酸氢钠摩尔比为16时,得到的IBA纯度高于97%,产率达81.25%;当单体质量分数为24.09%时,合成的PBI的η_(inh)为0.5033 dL/g,起始热分解温度高于550℃,800℃时质量保持率达73%;当纺丝溶液PBI质量分数为24%、电压为22 kV、推进速度为0.12 mL/h时,得到的PBI纳米纤维直径均一(约300 nm),表面光滑无串珠。

Polybenzimidazole(PBI)was synthesized through solution polycondensation by using N,N-dimethylacetamide as solvent and was produced into PBI nanofiber by electrospinning process.The influence of the isophthalaldehyde/sodium bisulfite molar ratio on the purity of isophthalaldehyde bisulfite adduct(IBA)and the monomer(IBA and 3,3′-diaminobenzidine)concentration on the inherent viscosity(η_(inh))of PBI and the electrospinning process parameters(solution concentration,voltage and feeding rate)on the morphology of PBI nanofiber was studied.The results showed that the purity and the yield of IBA was above 97%and up to 81.25%,respectively,when the isophthalaldehyde/sodium bisulfite molar ratio was 16;the obtained PBI hadη_(inh) of 0.5033 dL/g,the initial thermal decomposition temperature higher than 550℃and the weight maintenance rate of 73%at 800℃when the mass fraction of monomers was 24.09%;and the obtained PBI nanofiber had the uniform diameter of about 300 nm and a smooth surface with no beads when the mass fraction of PBI was 24%in the spinning solution,the voltage was 22 kV and the feeding rate was 0.12 mL/h.