Growth of copper organophosphate nanosheets on graphene oxide to improve fire safety and mechanical strength of epoxy resins

Recent advancements in mechanical properties of graphene-enhanced polymer nanocomposites: Progress, challenges, and pathways forward

The versatile properties of graphene-based polymers have captured substantial interest in recent years, making them a topic of significant research focus. This review paper aims to provide an in-depth analysis of the reported mechanical properties of graphene polymer nanocomposites, a highly promising class of materials for diverse industrial applications. Within this review, we emphasize the role of interactions between graphene and the polymer matrix in achieving uniform dispersion to prevent agglomeration and mitigate adverse effects on mechanical properties. Furthermore, we focus on functionalization as the main method of enhancing graphene physicochemical properties, highlighting its capacity to enhance homogeneous dispersion and significantly improve mechanical properties. These enhancements are contingent on factors such as the type and quantity of functionalization agents and the chosen technique. Additionally, we comprehensively examine recent experimental and theoretical research pertaining to the mechanical properties of graphene/polymer nanocomposites. Our analysis contains two primary polymer categories, namely thermoset and thermoplastic matrices, while also considering graphene loading type and volume fraction, as well as the influence of functionalization agents. This review uniquely addresses the existing gap in a comparative analysis between thermoset and thermoplastic matrices, offering insights into how different loading and functionalization methods influence mechanical properties. Moreover, we emphasize the need for further research in optimizing functionalization techniques and understanding the long-term stability of these composites, an area underexplored in current literature. This work stands out by highlighting future directions for refining synthesis techniques and expanding applications of graphene/polymer nanocomposites across industries such as aerospace, automotive, and electronics. Future endeavors may focus on addressing the challenges, refining synthesis techniques, and exploring novel applications, thereby contributing to the continued growth and evolution of graphene/polymer nanocomposites in the field of materials science.

Improving the Flame Retardancy and Mechanical Properties of Vinyl Ester Resins through Maleated Epoxidized Corn Oil/Epoxy Resin Additives for Sustainable Thermoset Composites

Thermoset polymers serve a significant role in modern industrial applications, and with a global annual output of over 65 million tons to meet this growing demand for sustainable materials, scientists and engineers need to go beyond what makes a material best for a certain use. Vinyl ester (VE) is a thermosetting polymer derived from polyester and epoxy resin. Its mixing properties distinguish it from its competitors, offering advantages in terms of curing efficiency, wettability, corrosion resistance, and low cost, which are crucial for modern industrial applications. Researchers have continuously explored the modifications of the intrinsic properties of VE using additives to enhance its flame retardancy and mechanical characteristics for more cost-effective and environmentally friendly materials applicable across various industries. In this study, we developed an easy-to-process eco-thermoset blend additive (50% v/v), known as maleated epoxidized corn oil/epoxy resin (MEPECO). Adding an optimal amount of MEPECO (5%) to the VE resin significantly improved its flame retardancy properties, as assessed by pyrolysis-combustion flow calorimetry, contact angle measurements, and thermogravimetric analysis. The mechanical properties, specifically strength, also showed substantial enhancement with the same optimal amount of MEPECO, as determined by flexural testing and spectral analysis. However, during the digestion of the eco-thermoset resin, the modulus and impact energy were notably lower owing to shear-yielding localization, as evidenced by the morphological analysis. This paper presents a novel in situ and straightforward technique for the easy and effective blending of eco-thermoset additives into petroleum-based epoxy resins, thereby facilitating their potential application in the development of sustainable green composite materials.

Heterostructured Graphene@Silica@Iron Phenylphosphinate for Fire-Retardant, Strong, Thermally Conductive Yet Electrically Insulated Epoxy Nanocomposites

The portfolio of extraordinary fire retardancy, mechanical properties, dielectric/electric insulating performances, and thermal conductivity (λ) is essential for the practical applications of epoxy resin (EP) in high-end industries. To date, it remains a great challenge to achieve such a performanceportfolio in EP due to their different and even mutually exclusive governing mechanisms. Herein, a multifunctional additive (G@SiO2@FeHP) is fabricated by in situ immobilization of silica (SiO2) and iron phenylphosphinate (FeHP) onto the graphene (G) surface. Benefiting from the synergistic effect of G, SiO2 and FeHP, the addition of 1.0 wt% G@SiO2@FeHP enables EP to achieve a vertical burning (UL-94) V-0 rating and a limiting oxygen index (LOI) of 30.5%. Besides, both heat release and smoke generation of as-prepared EP nanocomposite are significantly suppressed due to the condensed-phase function of G@SiO2@FeHP. Adding 1.0 wt% G@SiO2@FeHP also brings about 44.5%, 61.1%, and 42.3% enhancements in the tensile strength, tensile modulus, and impact strength of EP nanocomposite. Moreover, the EP nanocomposite exhibits well-preserved dielectric and electric insulating properties and significantly enhanced λ. This work provides an integrated strategy for the development of multifunctional EP materials, thus facilitating their high-performance applications.

Impact of Eco-Friendly Plaster Using Epoxy Resin and Epoxy Hardener on Mechanical Properties under Compression and Tension

BISCO plaster (BRP) is an environmentally friendly material with high mechanical properties and is considered a great elective to conventional materials such as gypsum and cement. Our investigation seeks to examine BISCO plaster (BRP) and a mixture of resin and hardener in three proportions (30%, 45%, and 60%) to achieve our ultimate goal, which is to preserve the environment and achieve the vision of the Kingdom of Saudi Arabia 2030 to reach zero carbon emissions by 2060? Emissions tests were performed, and although the CO2 level was zero, they emitted SO2 sulfur dioxide and NO2 nitrogen dioxide, and 60% was the lowest emission rate. We also used ANSYS 2023 R1 software to compare them with their mechanical properties resulting from tensile and compression testing. In this study, we looked closely at the mechanical characteristics of different materials designed for wall coverings, with particular emphasis on their environmental sustainability. We carried out experiments to gauge the tensile and compressive stress on samples with varying mixing ratios. Our main objective was on crucial mechanical properties such as the modulus of elasticity, ultimate tensile strength, yield strength, yield strain, modulus of resilience, and ductility. Through meticulous scrutiny, we determined that the amalgamation of these mechanical attributes at the 30% mixing ratio provides an optimal combination for attaining structural integrity, adaptability, and resilience in wall coverings. Significantly, this ratio also underscores a commitment to environmentally conscious material selection. Our study offers important new insights into the selection of wall covering materials by providing a detailed understanding of their mechanical behavior under various stress conditions. It aligns with the increasing significance of environmental responsibility in contemporary design and construction. By emphasizing the 30% mixing ratio, our findings establish a foundation for informed decision making, promoting the utilization of sustainable materials that achieve a balance between strength, flexibility, and longevity. This ensures optimal performance in practical applications while simultaneously minimizing the environmental impact.

Flame-Retardant Cycloaliphatic Epoxy Systems with High Dielectric Performance for Electronic Packaging Materials

Flame-retardant cycloaliphatic epoxy systems have long been studied; however, the research suffers from slow and unsatisfactory advances. In this work, we synthesized a kind of phosphorus-containing difunctional cycloaliphatic epoxide (called BCEP). Then, triglycidyl isocyanurate (TGIC) was mixed with BCEP to achieve epoxy systems that are rich in phosphorus and nitrogen elements, which were cured with 4-methylhexahydrobenzene anhydride (MeHHPA) to obtain a series of flame-retardant epoxy resins. Curing behaviors, flame retardancy, thermal behaviors, dielectric performance, and the chemical degradation behaviors of the cured epoxy system were investigated. BCEP-TGIC systems showed a high curing activity, and they can be efficiently cured, in which the incorporation of TGIC decreased the curing activity of the resin. As the ratio of BCEP and TGIC was 1:3, the cured resin (BCEP₁-TGIC₃) showed a relatively good flame retardancy with a limiting oxygen index value of 25.2%. In the cone calorimeter test, they presented a longer time to ignition and a lower heat release than the commercially available cycloaliphatic epoxy resins (ERL-4221). BCEP-TGIC systems presented good thermal stability, as the addition of TGIC delayed the thermal weight loss of the resin. BCEP₁-TGIC₃ had high dielectric performance and outperformed ERL-4221 over a frequency range of 1 HZ to 1 MHz. BCEP₁-TGIC₃ could achieve degradation under mild conditions in an alkali methanol/water solution. Benefiting from the advances, BCEP-TGIC systems have potential applications as electronic packaging materials in electrical and electronic fields.