MALDI-TOF MS对难溶聚芳酰胺PA6T的分析表征  

Characterization of Insoluble Polyamide-6,T by MALDI-TOF MS

作　　者：常静[1] 顾雪萍[1] 冯连芳[1] 胡国华 

机构地区：[1]浙江大学化学工程与生物工程系,化学工程联合国家重点实验室,浙江杭州310027 [2]法国洛林国家理工学院化学工程科学实验室,法国南锡54001

出　　处：《光谱学与光谱分析》2010年第1期159-164,共6页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(50728302);化学工程联合国家重点实验室项目(SKL-ChE-08D03)资助

摘　　要：选用五种样品试剂三氟乙酸、四氢呋喃、甲酸、乙腈、60%乙腈/5%三氟乙酸和两种不同的制样方法,采用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)表征难溶性聚合物聚对苯二甲酸己二酰胺(PA6T)的结构和分子量。发现以60%乙腈/5%三氟乙酸为样品试剂所得谱图的分子质量范围和信噪比最大,且溶剂法一步点样优于无溶剂法制样。获得了离子液体中合成产物PA6T的链结构,表明其主链为线性,未发现环状聚合物的存在,存在三种端基结构聚合体:两端均为氨基或羧基、或一端为氨基另一端为羧基。采用MALDI-TOFMS和SEC两种方法对比测量了PA6T的平均分子量和分子量分布指数,表明MALDI-OF MS测得的平均分子量低于SEC法,分子量分布指数也低于SEC法,这是由于MS处理数据时忽略了低分子量部分,且高分子量部分因难以离子化而无法得到引起的。对于难溶的聚芳酰胺类聚合物的结构和分子量及其分布表征,MALDI-TOF MS仍不失为一个好方法。Five different sample solvents （trifluoroacetic acid, tetrahydrofuran, formic acid, acetonitrile, 60% acetonitrile/5%trifluoroacetic acid） and two kinds of sample preparation methods were chosen for characterizing the structure,mole mass and mass distribution of insoluble polymer of polyamide-6, T （PA6T） by matrix assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF MS）. It was shown that the spectra with wide mole mass and high signal-to-noise （S/N） ratio were obtained, when using 60% acetonitrile/5% trifluoroacetic acid as solvent, and solvent sample preparation with one step droplet method was better than non-solvent sample preparation. The main chain structure of PA6T polymerized in ionic liquid was analyzed, which was linear without the presence of cyclic polymer. Three structures of end groups were obtained, carboxyl group or amino group at both ends or carboxyl group at one end and amino group at the other. The mean mole mass and mass distribution were obtained by MALDI-TOF MS and size-exclude chromatography （SFC）. It was shown that the mean mole mass by MALDI-TOF MS is lower than that by SEC and the mass distribution was narrower than that by SEC method, which resulted from the default of low mass fraction when calculated by exploring data and high mass fraction hardly detected for the difficulty of ionization. MALDI-TOF MS is a suitable method for the characterization of the structure and mole mass of insoluble poly（aro matic amide）.

关 键 词：MALDI-TOF MS PA6T 链结构 分子量 分子量分布 

分 类 号：O631.6[理学—高分子化学]