Journal of Applied Research in Chemical-Polymer Engineering

Abstract Research subject: Cellulosic nanomaterials, including cellulose nanocrystals, cellulose nanofibers, and bacterial cellulose, have attracted significant attention as reinforcing agents in epoxy matrices due to their low density, high mechanical strength, suitable elastic modulus, and renewable nature. However, the inherent hydrophilicity of cellulose nanoparticles and their poor interfacial adhesion with epoxy resins impose critical limitations on the mechanical and thermal performance of epoxy nanocomposites. Consequently, surface modification of cellulosic nanomaterials has emerged as a key strategy to enhance interfacial compatibility and improve the overall properties of epoxy-based nanocomposites.
Research approach: This study presents a comprehensive review and analysis of research published between 2023 and 2025, focusing on various surface modification techniques for cellulosic nanomaterials. These techniques include silane treatments, hydrophobic coatings, esterification reactions, and other chemical modifications. The primary objective of these approaches is to reduce the hydrophilicity of cellulose nanofibers, enhance interfacial adhesion between the reinforcing phase and the epoxy matrix, and promote uniform dispersion of nanomaterials within the nanocomposite structure.
Main results: The results of this study demonstrate that surface modification of cellulose nanoparticles significantly enhances their interfacial interactions and dispersion within the epoxy matrix, leading to a noticeable increase in the onset and peak thermal degradation temperatures, a reduction in the thermal degradation rate, and a measurable increase in char residue at elevated temperatures. Improved dispersion and reduced agglomeration of nanofibers result in substantial enhancements in mechanical properties, including tensile strength, elastic modulus, and stiffness, along with improved fracture behavior and effective inhibition of crack propagation. Quantitative analysis indicates that the surface modification method, functional group chemistry and density, nanofiber loading level, and dispersion uniformity play decisive roles in optimizing both thermal stability and mechanical performance. Overall, this work provides a systematic, quantitatively driven engineering framework for the design of durable, high-performance epoxy nanocomposites suitable for high-temperature and demanding industrial applications.

Abstract Research subject: Magnesium ethoxide is a metal alkoxide used as a support for preparation of Ziegler-Natta catalyst. This important material which is used in HDPE production plants is not produced in Iran. It forms a complex with the catalyst that results in increase of the number of the reacting transition metal atoms inside it. Therefore the catalyst activity increases. The chemical reaction between magnesium and ethanol, in presence of iodine, results in magnesium ethoxide production.
Research approach: In this work, by performing analyses such as thermal gravimetric analysis (TGA), BET and scanning electron microscopy (SEM), the effects of reaction conditions such as iodine/magnesium, ethanol/magnesium, temperature and mixer speed on morphology and characteristics of magnesium ethoxide were investigated.
Main results: By using Iodine, proper morphology of product was obtained. The mixer rotation speed didn't affect the reaction time. The particle size of the product was dependent on the magnesium amount and particle size and mixer speed. Increasing the rotation speed of the mixer at high amount of magnesium (low ethanol/magnesium) led to more collision of the particles and therefore finer product particles. Reaction at temperatures as low as 60 ^ₒC led to formation of fine particles with undesirable flake-like morphology. Magnesium with two average particle sizes (420 and 840μm) was used. It was shown that synthesis with magnesium of 840 μm(FW40) led to a sample similar to the commercial one with appropriate specific surface area. Lowering the temperature from 110 to 100 ^ₒC and reflux of ethanol at boiling point resulted in higher specific surface area.

Abstract In this research, closed-cell natural rubber foams were produced using a single-step compression molding. The effect of carbon black content on morphology, physical and mechanical properties of the foams were examined. Results showed that in this methodology, the foam density was independent of reinforcement percentage, which is a unique characteristic of single-step foams that contrasts with other previous observations. The study of curing behavior of foam compounds showed that the carbon black increasing from 0 to 30 phr increased the crosslink density (CLD) from 6.5 to 8.3*10^-5 mol/cm³, the cure rate from 16.1 to 23.2 (%/min) and the ultimate torque from 5.8 to 10.4 Nm, while, reduced curing time from 9.2 to 5.8 min. The scanning electron microscope (SEM) results showed that the reinforcement acted as a nucleation agent increasing the cell density from 8 N/cm³ to 140 N/cm³ and reducing the cell size from 579µm to 255µm. The increase of reinforcing content in the produced foams reduced the cells size and enhanced the properties of the rubber matrix. Accordingly, the modulus and hardness of the foams were increased by 0.8MPa and 40 shore A, respectively. Results of sound absorption and reflection showed that the rubber foam reflects the sound waves more than 90% and absorbs waves about 10%.