SYNTHESIS AND PHYSICOCHEMICAL CHARACTERIZATION OF FILM-FORMING POLYMERS BASED ON HYDROLYZED POLYACRYLONITRILE AND DIVERSE CROSS-LINKING AGENTS

ABSTRACT

This paper discusses the development of high-adhesion film-forming organic coatings derived from industrial waste. The research focuses on the synthesis of polymer compositions based on hydrolyzed polyacrylonitrile (HPAN) using various cross-linking agents, including glycerin, dimethylol urea, and dibutyl phthalate. The synthesis process was investigated under varying parameters, specifically targeting the influence of reaction temperature (30–50°C), reagent ratios, and the nature of the solvent. Experimental results indicate that increasing the HPAN concentration and temperature facilitates a structural transition from a linear chain to a complex branched network, leading to the formation of a solid, viscous, and insoluble mass with high molecular weight. The physicochemical properties of the synthesized poly(oligo)mers were evaluated, demonstrating their effectiveness as protective coatings and corrosion inhibitors. This study provides both a theoretical framework for polymer modification and a practical technological solution for repurposing industrial waste into high-value functional materials.

АННОТАЦИЯ

В данной статье рассматривается разработка высокоадгезионных пленкообразующих органических покрытий, полученных из промышленных отходов. Исследование сосредоточено на синтезе полимерных композиций на основе гидролизованного полиакрилонитрила (ГПАН) с использованием различных сшивающих агентов, включая глицерин, диметилолмочевину и дибутилфталат. Процесс синтеза изучался при варьировании различных параметров, в частности, влияния температуры реакции (30–50°C), соотношения реагентов и природы растворителя. Экспериментальные результаты показывают, что повышение концентрации ГПАН и температуры способствует структурному переходу от линейной цепи к сложной разветвленной сетке, что приводит к образованию твердой, вязкой и нерастворимой массы с высокой молекулярной массой. Были оценены физико-химические свойства синтезированных поли(олиго)меров, демонстрирующие их эффективность в качестве защитных покрытий и ингибиторов коррозии. Данное исследование представляет как теоретическую основу для модификации полимеров, так и практическое технологическое решение для перепрофилирования промышленных отходов в высокоценные функциональные материалы.

Keywords: Hydrolyzed polyacrylonitrile (HPAN), film-forming polymers, cross-linking agents, adhesion, synthesis technology, corrosion inhibitors, industrial waste utilization.

Ключевые слова. Гидролизованный полиакрилонитрил (ГПАН), пленкообразующие полимеры, сшивающие агенты, адгезия, технология синтеза, ингибиторы коррозии, утилизация промышленных отходов.

INTRODUCTION

Synthetic and natural polymers are essential components of modern life, utilized in nearly every industrial sector. Today, both traditional synthetic and natural polymer materials are widely employed due to their versatility. However, a significant drawback of these polymers is the deficiency of certain specific properties compared to other advanced materials. Consequently, many polymer-based end products—such as cables, carpets, furniture cabinets, and various fabrics—require the formation of a high-quality surface coating to enhance durability and performance[1-3].

This creates a critical necessity for developing and utilizing polymer compositions with high adhesive properties. The development of technologies for producing high-adhesion coatings by cross-linking various functional groups found in industrial waste using diverse agents is of both practical and theoretical significance. Specifically, the synthesis of highly dispersed organosilicon-based materials and modified polyacrylonitrile derivatives offers a sustainable pathway for industrial waste utilization[4-6].

In this context, the present work focuses on the synthesis of film-forming organic compounds based on hydrolyzed polyacrylonitrile (HPAN). By employing cross-linking agents such as glycerin, dimethylol urea, and dibutyl phthalate, we aim to create polymer matrices with superior adhesive and anti-corrosion characteristics. The study further investigates the impact of reaction parameters—including temperature, reagent ratios, and solvent nature—on the structural transition and final properties of the synthesized coatings[7-9].

MATERIALS AND METHODS

 The primary raw material used in this study was hydrolyzed polyacrylonitrile (HPAN) derived from industrial by-products. Chemical modification and cross-linking processes were conducted using analytical grade reagents: glycerin, dimethylol urea, and dibutyl phthalate.

The synthesis was carried out in a three-necked flask equipped with a mechanical stirrer, a reflux condenser, and a thermometer. The reaction temperature was maintained within the range of 30–50°C. The ratio of HPAN to cross-linking agents was varied, starting from a 10:1 ratio, and the reaction was monitored over a specific duration to ensure complete interaction[10].

The dynamic viscosity of the synthesized polymer systems was determined using a viskotester at various stages of the reaction. The solubility of the resulting poly(oligo)mers was evaluated in distilled water and common organic solvents. To assess the film-forming capabilities, the compositions were applied to metal surfaces, and their adhesion and protective properties were analyzed.

RESULTS AND DISCUSSION

The physicochemical properties of the polymer synthesized at a baseline temperature of 30°C were evaluated. The reaction involved hydrolyzed polyacrylonitrile (HPAN) interacting with glycerin, dimethylol urea, and dibutyl phthalate at various molar ratios.

Table 1.

Различные молярные соотношения

The experimental data from the table was subjected to mathematical processing to determine the regression equation. The fact that the obtained values approach unity  indicates a high degree of correlation between the experimental results and theoretical calculations, confirming the reliability of the findings.

Figure 1. Changes in the viscosity of the polymer based on hydrolyzed polyacrylonitrile, glycerin, dimethylol urea, and dibutyl phthalate at 30°C.

The physicochemical properties of the polymer synthesized at a baseline temperature of 40°C were evaluated. The reaction involved hydrolyzed polyacrylonitrile (HPAN) interacting with glycerin, dimethylol urea, and dibutyl phthalate at various molar ratios.

Table 2.

Values

Figure 2. Changes in the viscosity of the polymer based on hydrolyzed polyacrylonitrile, glycerin, dimethylol urea, and dibutyl phthalate at 40°C.

The dependence of the polymer system's viscosity at an elevated temperature of 40°C is shown in Figure 2. It was observed that as the temperature rises, the tendency of the mass to solidify due to internal cross-linking decreases. This is attributed to the fact that higher temperatures increase the fluidity of the molecules and enhance the mobility of the functional groups, preventing premature gelation.

The physicochemical properties of the polymer synthesized at a baseline temperature of 50°C were evaluated. The reaction involved hydrolyzed polyacrylonitrile (HPAN) interacting with glycerin, dimethylol urea, and dibutyl phthalate at various molar ratios.

Table 3.

Values

An increase in temperature significantly accelerates the reaction kinetics and enhances the yield of the polymer grafting process. It was observed that when the temperature exceeds 50°C, the system undergoes complete interchain bonding, leading to the formation of a solid, viscous mass. This transition is primarily attributed to the internal cross-linking (cyclization or networking) within the HPAN structure. The effect of the reactant ratios and temperature on the final viscosity of the products was systematically analyzed (as detailed in Tables 1-3).

Figure 3. Changes in the viscosity of the polymer based on hydrolyzed polyacrylonitrile, glycerin, dimethylol urea, and dibutyl phthalate at 50°C.

The kinetic curves of the polymer's viscosity at 50°C are illustrated in Figure 3. Mathematical processing of the tabular data to derive the regression equation showed that the correlation coefficient is equal to unity. This demonstrates an absolute correspondence between the experimental results and theoretical calculations, confirming the high precision and reliability of the conducted experiments. Furthermore, it was observed that as the temperature rises, the tendency for the mass to solidify due to internal cross-linking decreases. This phenomenon is explained by the fact that increased thermal energy enhances the fluidity of the molecules and significantly boosts the mobility of the functional groups.

CONCLUSION

Analysis of Tables 1-3 indicates that the viscosity of the synthesized polymer increases proportionally with the rise in molecular weight as the concentrations of glycerin, dimethylol urea, and dibutyl phthalate, as well as the temperature, are increased. It was found that at a component ratio of 50:14, the mixture's viscosity becomes too high to be measured, representing a critical point of gelation. The decrease in this threshold ratio as temperature rises is attributed to the acceleration of internal cross-linking and increased reaction yield.

Based on these findings and the assessment of the product's adhesion to metal surfaces, various optimal ratios were investigated across different temperatures. Although increasing the temperature allows for a reduction in the amount of cross-linking agent, it was observed to cause instability in the resulting film coating. Therefore, it was concluded that a 5:1 ratio at a temperature of 30°C provides the optimal balance, ensuring the desired physicochemical properties and stable film formation.

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