STRUCTURAL AND THERMAL CHARACTERIZATION OF A EGUF THERMOSTABLE COATING VIA CHROMATOGRAPHIC-MASS SPECTROMETRY ANALYSIS

ABSTRACT

This study investigates the thermal and structural properties of a EGUF (ethylene glycol–urea–formaldehyde system) - based thermostable coating synthesized using ethylene glycol–urea–formaldehyde derivatives. Chromatographic-mass spectrometry (GC-MS) was employed to determine the molecular composition and fragmentation behavior of the synthesized compound. The ionization of the thermostable coating revealed the presence of molecular and fragment ions with m/z values of 221, 189, 161, 110, 73, and 58 within the retention time of 10.639 to 10.708 minutes. The detailed fragmentation pathway indicates sequential dissociation starting from side chains followed by the breakdown of the main chain, confirming the proposed molecular structure and thermal stability of the coating.

АННОТАЦИЯ

В данной работе изучены термические и структурные свойства термостойкого покрытия, синтезированного на основе системы ЭГМФ (этиленгликоль–мочевина–формальдегид). Для определения молекулярного состава и поведения фрагментов соединения при ионизации использован метод хромато-масс-спектрометрии (ГХ–МС). В результате ионизации термостойкого покрытия были зафиксированы молекулярные и фрагментные ионы с m/z значениями 221, 189, 161, 110, 73 и 58 в пределах времени удерживания от 10.639 до 10.708 минут. Подробный анализ путей фрагментации показал, что распад молекулы начинается с боковых цепей и продолжается разрушением основной цепи, что подтверждает предложенную молекулярную структуру и термическую стабильность покрытия.

Keywords: EGUF (ethylene glycol–urea–formaldehyde system), thermostable coating, Chromatographic-mass spectrometry (GC-MS), fragment ions, ethylene glycol, urea, formaldehyde

Ключевые слова: ЭГМФ (система этиленгликоль–мочевина–формальдегид), термостойкое покрытие, хромато-масс-спектрометрия (Х–МС), фрагментные ионы, этиленгликоль, мочевина, формальдегид.

1. Introduction 

Chromatographic-mass spectrometry (XMT) is a modern analytical technique that integrates chromatography (GC or LC) with mass spectrometry (MS) to provide precise qualitative and quantitative analyses of complex mixtures[1]. It is widely applied across various fields including pharmaceuticals, materials science, petrochemicals, and environmental monitoring due to its high sensitivity and reliability[2]. This study utilizes XMT to analyze a EGUF-based thermostable polymer coating synthesized from ethylene glycol–urea–formaldehyde, aiming to elucidate its molecular structure, fragmentation pattern, and thermal behavior under controlled analytical conditions[3-5].

2. Materials and Methods 

The EGUF thermostable coating was synthesized via a condensation reaction involving ethylene glycol–urea–formaldehyde derivatives, under the following general reaction pathway:

The chromatographic-mass spectral analysis was conducted using an Agilent MSD 5975C-GC7890A system equipped with a standard HP-5MS column. The control parameters ranged from 0°C to 300°C, with an initial sample temperature between 30°C and 100°C. The coating was first ionized to form molecular and fragment ions, which were subsequently analyzed based on their m/z values.

3. Results and Discussion 

The GC-MS analysis of the synthesized thermostable EGUF coating revealed the primary molecular ion peak at m/z 221, corresponding to the molecular weight of the target compound. The formation of this ion occurred between 10.639 to 10.708 minutes under selected chromatographic conditions (Figure-1).

Figure 1. Chromato-mass spectrum image of the EGUF thermostable coating

Subsequent fragmentation led to the identification of the following significant ions:

- m/z 189: Formed by the loss of an amine group radical from the parent ion, corresponding to the (((2-acetoxyethoxy)carbonyl)amino)methyl acetate ion.

- m/z 161: Attributed to the loss of a carbonyl group (CO), forming the 5,10-dioxo-2,6,9-trioxa-4-azaundecan-1-ylium ion.

- m/z 110: Corresponds to the 2-((propoxycarbonyl)amino)ethan-1-ylium ion, resulting from further side-chain fragmentation.

- m/z 73: Derived from the elimination of a methylene radical from the previously formed ion.

- m/z 58: Generated due to the release of an -NH- radical from the oropyl ethylcarbamate ion, indicating the presence of 2-ethoxy-2-oxoethane-1-ylium ion.

The ion formation patterns adhered to expected kinetic and thermodynamic fragmentation laws. The initial dissociation of low-energy side chains was followed by progressive degradation of the polymer backbone. These findings confirm the structural validity and stability of the synthesized thermostable coating.

4. Conclusion 

The application of chromatographic-mass spectrometry in this study enabled a detailed structural and thermal characterization of the EGUF thermostable coating. The formation of specific molecular and fragment ions supports the proposed molecular structure. The fragmentation pathway aligns with theoretical dissociation mechanisms, demonstrating the efficacy of GC-MS in analyzing thermostable polymeric materials. This study contributes to the understanding of urea-based thermostable coatings and provides a methodological foundation for further research in polymer chemistry and materials science.

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