MALDI‐TOF MS Investigations of Polyamides Synthesized in Autoclave and Microwave Assisted Processes

Abstract

Summary: Due to their excellent physical and chemical properties polyamides (PA) are used in many industrial processes. The most common products are the aliphatic polyamides synthesized by a conventional melt-polycondensation method of AH-salt in an autoclave. High temperatures, high pressure and long reaction times are necessary. On the other hand the polyamide synthesis can conducted as solution polycondensation in a microwave oven. Moreover the higher heating efficiency of microwave irradiation reduces the reaction time to about 20 minutes. The main focus of this study lies on the end group analysis by MALDI-TOF MS (matrix assisted laser desorption/ionization time of flight mass spectrometry) of aliphatic polyamides produced by autoclave -as well as microwave assisted synthesis by AABB-type condensation. The results show differences in the end group formation depending on the chosen reaction conditions. In case of following modification or protecting group chemistry, it is of course important to know the kind of end groups of the polyamide.

Thermal stability of ester linkage in the presence of 1,2,3‐Triazole moiety generated by click reaction

“…Another peak ( γ ) at m / z ≈ 1484 corresponds to carboxylic acid form of PS (13 repeating units). It is noted that two sodium ions are attached to carboxylic acid end functionalized polymers when NaTFA was used as a salt for MALDI‐TOF . Because the olefin form of PS degraded further to carboxylic acid form of PS easily, the intensity of the γ peak was much higher than β peak.…”

Co(III) complex mediated microwave‐assisted synthesis of PAN

“…The main advantages of microwaves over traditional heating (hot plates, bunsen burner, etc.) for preferring an organic reaction are an increased rate of production, shorter reaction time (usually 1/1000), improved product characteristics, uniform processing, less floor space required, and convenience and controllability of the process 6–10. The mechanism of energy transfer using microwave field is considerably different from the well‐established modes (radiation, conduction, and convention) of heat transfer.…”