Papers by Keyword: Epoxy

Abstract: The addition of ceramic nanoparticles to the polymer resin enhances the performance of the composite, enabling the use of such materials in industries such as automobiles and aircraft. This work aims to evaluate the characteristics of epoxy resins by introducing (1%, 3%, 5%, and 7% wt. nano dioxide silica). Using the "hand lay-up " process, about 125 samples were prepared for conducting tests (Hardness, Tensile strength, Impact, Water Absorption) and analyzing results by (SPSS-Scheff). The addition of 7% nano-silica dioxide particles to epoxy considerably raises the hardness values (85.350+.5150 shore D), according to the hardness results. The best average values of the tensile strength and impact (292± 2.828MPa, 54.00 ± 2.828 J/m²) were at the samples (Epoxy- 3% nano-silica dioxide) when compared with other samples. The values of elongation at break reduce through rising concentration, weight fractions of nano-silica dioxide in epoxy, and the best average values of the elongation at break (3.150± .2300 %) were at the samples (Epoxy- 1% nano-silica dioxide). The percentage of water absorption values improved by increasing the weight fraction concentrations of nano-silica dioxide in epoxy, and the best water absorption percentage was (.017 ±.003414%) in the samples (epoxy-1% nano-silica dioxide). Statistically, very large variations were observed of hardness, tensile strength, elongation at break, impact strength, and water absorption (Sig 0.01, 0.04, 0.003, 0.02, and 0.002) respectively, and this indicates an improvement in the properties when addition nano-silica dioxide to the epoxy resin

Abstract: The good environmental effect and possible cost reduction which can be achieved by reinforcing natural fibers in composites while improving some properties led to the development of these materials in various fields. In terms of mechanical properties of composites with natural fibers, both fiber loading and their orientation in the matrices are important factors. In this research work, the effects on the mechanical properties of reinforcing quasi-unidirectional salago fiber in epoxy resin were investigated. Varying alkaline treated fiber contents of 5 %, 10 % and 15 % by weight were characterized through tensile, flexural and impact tests. Fracture analysis after mechanical testing was done with the aid of optical microscopy. As the fiber weight content increases, results revealed enhancements on tensile strength, modulus of elasticity, flexural modulus and impact strength. Overall, the 15 wt. % fiber loading obtained the highest mechanical properties with average tensile and Izod impact strengths of 89.2 MPa and 137 J/m, respectively.

Abstract: This paper deals with the problematics of utilization of waste perlite from production of expanded perlite in polymer-based material. The goal of this paper is to develop repair mortar containing as high amount of waste perlite as possible as substitution for filler. The resulting mortar exhibits very high physical-mechanical properties such as high bonding strength to a large variety of building materials. The microstructure and the re-dispersibility of filler were also studied.

Abstract: Fibres anisotropy and their poor adhesion to the epoxy matrix are challenges in developing polymeric epoxy composite for structural applications. Filling of epoxy with reinforcing particles has potential for producing isotropic composites. In this study, epoxy-aluminium particulate composites were developed through combined-stir-techniques. Their interfacial adhesion and microstructural properties were examined. Results obtained indicated bonding of aluminium particles to epoxy through bidentate coordinate bond. Variations observed in the Fourier Transform Infrared spectrographs (FTIR) of both composites’ grades confirm discrepancies in interactions of aluminium micro and nanoparticles with epoxy. A good interfacial adhesion of aluminium nanoparticle with epoxy established by both optical and scanning electron microscopes is an indication of good mechanical performance of the epoxy composites.

Abstract: For material engineers, greater consumption of fuel by the aviation and automobile sector is a greater challenge. Based on this scenario, exploration towards the generation of new engineering materials which are lighter with superior mechanical properties in the field of aviation and automobile sector is found to be important. Reduce the fuel utilization up to 70% in the above mentioned sectors is the 2025 universe vision. According to substantial reports, eco-friendly products can be refined from natural fiber composites. Tribological characteristics of NaOH treated chopped abaca fiber reinforced epoxy composites were discussed in this paper. Using compression moulding technique, NaOH treated chopped abaca fiber reinforced epoxy composites were fabricated by varying the abaca fiber volume fraction to 10 wt%, 15 wt%, 20 wt%, and 25 wt%. Pin-on-disk wear testing machine is used in this study for the dry sliding wear test at different loads of 10N, 15N and 20N. The wear test sample results were compared with neat epoxy composites. The composites containing abaca fiber shows better tribological characteristics than the neat epoxy composites. The investigation results shows that wear results of the composites can be very much influenced by the speed, sliding distance and applied load. 25wt% of abaca fibre volume fraction composites was found to be the optimum value.

Abstract: Researchers have been busy developing new environmental friendly products and materials based on sustainability principles to reduce pollution and prevention of our resourceful non-biodegradable and non-renewable sources. Over synthetic materials there are many unquestionable focal points for natural fibers and some of them are low thickness, least waste transfer issues and also equivalent quality. In this research the mechanical properties of abaca fiber reinforced epoxy composite were evaluated. Then with the help of compression moulding process, different composite samples of varying fiber volume fractions were prepared. Different mechanical tests such as tensile, flexural, impact and hardness were conducted on the prepared samples. 25 wt% of abaca fibre volume fraction composites shows better mechanical properties.

Abstract: Thermoset adhesives convert from liquid to solid due to chemical reactions. Once cured, these adhesives carry the potential to create strong load-bearing joints, resisting even severe detrimental service conditions. In the progress of curing of a thermoset adhesive the viscoelastic properties of the resin and hardener formulation change as the chemical reaction proceeds. Gelation occurs once a continuous 3-dimensional network of polymer chains has been created. After gelation, the microstructure of the resin is fixed and further cure is affected by diffusion limitations [1]. Mastering of the curing kinetics and the physicochemical changes in the transition from the liquid to the solid-state is essential to reliably process adhesives in industrial applications. Rheological experiments in parallel plate configuration have become a well-established practice in investigating viscoelastic properties in the progress of curing. In practice, it has shown to be challenging to access the full range of viscoelastic parameters of thermoset resins with a low initial viscosity from the very beginning of the curing reaction to the post-cure consolidation of the vitrified polymer. This paper will discuss experimental methods and criteria for the viscoelastic analysis of curing thermoset adhesives and present experimental data of the time-, temperature-, and frequency-dependent viscoelastic properties of a curing thermoset epoxy in relation to the features of its time-temperature-transformation-diagram.

Abstract: Polymeric fibers are used for reinforcement of composites in all kinds of applications, from sport and recreation products to military equipment. Since these fibers have high energy absorption on ballistic impact, the defense industry uses them to manufacture lightweight armor. In many cases, armors are exposed to degradation agents such as heat, humidity, and radiation. The macromolecular changes of polymer fibers exposed to degradation agents can affect the mechanical and ballistic properties of the composite. The present work studies the ballistic performance of aromatic polyamide (aramid) fabric-reinforced composite using two different matrices, degraded by gamma radiation. The results suggest that gamma radiation can change the penetration failure mechanism of the composite in a variety of ways depending on the matrix, compromising its performance.

Abstract: The paper deals with problematics of the influence of size and shape of test specimens prepared according to the valid standard procedures in comparison to specimens prepared according to the standards used for different types of materials (grouts, coatings). The aim of this paper is to verify the possibility of using non-standard specimen sizes to reduce the economic demands of the development of building materials. The issue is tested on the polymer composites prepared in three different amounts of the filler. The polymer composite based on epoxy resin serves as a representative and homogenous material which achieves the same results under various curing temperatures and humidity. The porous structure of prepared samples was also studied and its effect on the selected mechanical properties was observed. It was shown that the specimen shape and size had impact on the mechanical properties of epoxy-based composites.

Abstract: The paper presents the effect of ground glass (GG) particles on the water absorption and tensile properties of epoxy. The GG particles contents in the epoxy were 0, 5, 10 and 15% (by volume). The results showed that the GG particles in the epoxy changed the water absorption behaviour from Fickian to non-Fickian. At the GG particles content of 15%, the equilibrium water uptake increased almost double, but the diffusion rate decreased by about 85% compared to the unfilled epoxy. In dry condition, the tensile strength tended to decrease with increasing the GG particles content, by about 11% at the GG content of 15% compared to that of the unfilled epoxy; however, the elastic modulus tended to increase linearly with the GG content. In wet condition, up to the GG content of 10%, the tensile strength decreased by about 77% compared to that of the unfilled epoxy; however, at the GG particles content of 15%, the tensile properties were improved.