论文部分内容阅读
极性-共轭双取代乙炔-苯丙炔酸在Pd(PPh3)2Cl2催化下直接通过易位催化机理聚合为低聚物.单体苯丙炔酸由两步制得,先通过液溴和肉桂酸的加成反应得到二溴代苯丙酸,然后消去两分子溴化氢得到单体.通过红外光谱(IR)、核磁共振(NMR)对单体及低聚物的结构进行了表征.凝胶渗透色谱(GPC)结果显示,聚合反应以甲苯作溶剂,75℃下效果最好,产率中等.这种共轭低聚物可以溶于四氢呋喃(THF)等极性溶剂,TGA结果表明低聚物热稳定性高.紫外可见吸收光谱(UV-Vis)显示,由于聚合后共轭主链大大增长,苯丙炔酸低聚物骨架上电子的跃迁使得低聚物的四氢呋喃溶液在波长高于310 nm光谱的区域中有吸收.荧光光谱(FS)显示,低聚物的四氢呋喃溶液在342 nm激发光下发蓝光,420 nm处有特征荧光发射峰.
Polar-conjugated disubstituted acetylene-phenylpropynic acid polymerizes directly to oligomer under the catalysis of Pd (PPh3) 2Cl2 through metathesis catalytic mechanism.The monomer phenylpropynic acid is obtained from two steps by liquid bromine and Addition reaction of cinnamic acid to dibromobenzenepropionic acid, and then remove two molecules of hydrogen bromide to obtain the monomer.The structure of monomer and oligomer were characterized by IR and NMR. Gel permeation chromatography (GPC) showed that toluene was the best solvent for the polymerization at 75 ℃, and the yield was moderate.The conjugated oligomers could be dissolved in polar solvents such as tetrahydrofuran (THF) The thermostability of the oligomer is high. UV-Vis shows that due to the great increase of the conjugated main chain after the polymerization, the transition of the electron on the phenylpropynic acid oligomer skeleton makes the tetrahydrofuran solution of the oligomer at the wavelength Absorption was observed in the region above 310 nm, and the fluorescence spectrum (FS) showed that the oligomer in THF solution showed blue light at 342 nm and characteristic fluorescence at 420 nm.