卟啉锌末端功能化的PMMA活性自由基聚合与非线性吸收性能研究

Atom Transfer Radical Polymerization and Nonlinear Absorption Properties of Zincporphyrin-end-functionalized Polymethacrylate

以α-溴代异丁酰溴封端的5,10,15,20-四对羟乙基苯基卟啉锌三丙酸酯为引发剂,通过原子转移自由基聚合方法(ATRP)合成卟啉锌末端功能化的PMMA高分子聚合物。通过红外光谱仪和氢核磁共振波谱对聚合物的结构进行了确定。利用GPC测试了聚合物分子量、分子量分布,研究了其聚合过程动力学,结果表明聚合过程符合一级反应动力学。通过Z-扫描技术测试了ns和ps脉冲激光下的非线性特性,拟合结果样品的非线性吸收系数β分别为4.5×10-10m/W和6.0×10-12m/W。样品对ns和ps激光均有非线性吸收特性,且ns脉冲下β值大于ps,说明样品三重激发态吸收截面大于单重激发态。

Used α-bromo-isobutyry Ibromide end-caped 5,10,15,20-tetra（p-hydroxyethylphenyl） zincporphyrin tripropionate as indicator,zincporphyrin-end-functionalized polymethacrylate（PMMA） was synthesized by atom transfer radical polymerization（ATRP） method.The structure of the prepared polymer was determined by infrared spectrum and nuclear magnetic resonance hydrogen spectrum techniques.The molecular weight and molecular weight distribution of the polymer samples were measured by gel permeation chromatograph（GPC） technique.Polymerziation reaction kinetics of the synthesized polymer was also studied by GPC.The rusults showed that polymerziation process followed a first-order reaction kinetics.By z-scan method,nonlinear optical properties of the polymer sample were tested using ns and ps pulsed laser.By fitting the experimental results,nonlinear absorption coefficient of the polymer sample,β is 4.5×10-10m/W and 6.0×10-12m/W,respectively.The results displayed that the prepared polymer sample has nonlinear absorption characteristic for ns and ps pulsed laser.Furthermore,β value under ns-laser pulse is bigger than that under ps-laser pulse,showing that the triplet excited state absorption cross-section of the sample is larger than singlet excited state absorption cross-section.