Analysis of N-Methylmelamine Resins with Combined GPC, HPLC, Mass Spectrometric Techniques

Abstract

This article deals with the development of methods for characterization and structural elucidation of N-methylmelamine resins as well as the cured material and composites made with these products. Resin characterization was achieved by ESI-ion trap MS and HPLC=PDA=MS n , which made the assignment of each species in the mixture possible. GPC as well as MS were used to follow the curing of the resin. Completely cured resins and composites are no more soluble in any solvent, and, therefore, the characterization was carried out with analytical pyrolysis and thermally assisted hydrolysis and methylation (THM) hyphenated to a GC=MS system.

IR spectroscopy: Suitable method for determination of curing degree and crosslinking type in melamine–formaldehyde resins

“…. However, completely cured resins cannot be analyzed with these methods due to their limited solubility . Others used capillary zone electrophoresis‐MS (ion trap or Q‐ToF) respectively, HPLC‐MS (high‐resolution LTQ‐Orbitrap) combined with NMR and Fourier transform infrared (FTIR) analysis for the semiquantitative characterization of MF condensates.…”

Novel Electrically Conductive Melamine‐formaldehyde Nanocomposite Based on Graphite Nanosheets

“…The thickness of the nano sheets is in the nanometer scale and ranged from 100 to 400 nm. Several groups reported similar sheet sizes of 1–20 µm and sheet thicknesses ranged from 50–100 nm . The structure and size of a GNS particle are strongly depending on the degree of exfoliation which is primarily affected by the exfoliation time and temperature.…”

“…As shown in Figure , the thermal decomposition thermogram for pure MF consist of several degradation steps: a slow weight loss step between 50–150 °C; second slow weight loss step between 150–364 °C; a rapid weight loss between 364–400 °C; another slow weight loss region between 400–660 °C, and a final degradation step above 660 °C. These transition steps are attributed to water evaporation; release of formaldehyde and amine, release of formadelhdye, amine, carbon dioxide, and ammonia; degradation of melamine; and the extensive degradation of MF and the formation of HCN, CO, and CO 2 , respectively …”

Rapid Melamine-Formaldehyde Resin Characterization by Means of Quantitative13C NMR with Polarization Transfer

“…Several analysis techniques can be applied for resin investigation, such as elemental analysis, wet-chemical methods, high-performance liquid chromatography (HPLC), gel permeation chromatography (GPC), capillary zone electrophoresis, mass spectrometry (MS), and infrared and Raman spectroscopy or nuclear magnetic resonance spectroscopy (NMR) and combinations thereof. [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22] In particular, NMR-based methods often suffer from long measurement times. [3][4][5]11,13,23] Chemical compositions of melamine resins (sum parameters: formaldehyde content per melamine and degree of etherification) are mostly determined by wet-chemical methods, which are usually time-consuming procedures.…”

“…Molar mass investigations are usually performed by size exclusion chromatography. [8,18,32] For investigations of resin structure, HPLC in combination with MS detection is the method of choice. [21,22] In industry, average molar masses of melamine resins are compared by their viscosity at a certain concentration or by their content of monomeric structures.…”