对位芳纶纤维及其打浆粉末端基结构的MALDI-TOF MS分析

Study on the End-group Structure of PPTA Fiber and Its Beating Powder by MALDI-TOF MS

关键词:  基质辅助激光解吸电离飞行时间质谱  对位芳纶纤维  打浆粉末  端基结构

Key Words:matrix-assisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS)  PPTA fiber  beating powder  end-group structure

摘要:利用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)对两种对位芳纶短切纤维(A1-PPTA、A2-PPTA)及其打浆粉末的端基结构进行分析,通过谱图特征峰与端基结构的对应关系,分析端基结构与反应机理的关联性及打浆过程产生粉末的原因。结果显示,A1-PPTA和A2-PPTA的聚合过程均采用了近似等摩尔的反应物来控制聚合过程；A2-PPTA的聚合过程发生溶剂链转移的几率更高；A2-PPTA中存在较多不利于纤维强度的端基结构，导致其打浆过程中产生更多粉末。

Abstract:Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was used to study the end-group structure of two kinds of poly (p-phenylene terephthalamide)-PPTA short-cut fiber (A1-PPTA fiber and A2-PPTA fiber)and the PPTA powder produced by beating the PPTA fibers during the paper-making process. The basic database of the spectral characteristic peak and the end-group structure was established to reveal the relationship between the reaction mechanism and the end-group structure, and to find the producing causes of the PPTA powder during the beating process. The results showed that polymerization process for A1-PPTA fiber and A2-PPTA fiber were both carried out with an approximate equivalent amount of reactants. The probability of chain transferring to solvent in A2-PPTA fiber was higher than A2-PPTA fiber; The existing of more end-group structures which were not benefit to fiber’s mechanical strength in A2-PPTA fiber caused more large amount of powder in the beating process.