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Glass fiber epoxy composites are widely used in industries. Liquid epoxidized natural rubber was added to epoxy as the matrix for a fiber-reinforced composite in order to improve its mechanical properties whilst E-glass fiber was used as the composite reinforcement. Flexural test, Izod impact test, tensile test, thermogravimetric analysis, and scanning electron microscopy were performed to investigate the effect of liquid epoxidized natural rubber addition and glass fiber loadings on the mechanical properties of the composite. It was observed that the flexural strength and flexural modulus of the samples increased with increasing glass fiber percentage with 9% as the maximum weight percentage recorded. The tensile strength and Young’s modulus increased with increasing glass fiber content until it reached the maximum value at 9 wt% of glass fiber. The same trend was observed with the impact value of the samples. All the tests were conducted for the composite with and without liquid epoxidized natural rubber addition. The presence of liquid epoxidized natural rubber improved the mechanical properties of the composites due to the plasticizing effect of the rubber particles in the matrix. Thermogravimetric analysis revealed the thermal stability of the composites whilst the scanning electron microscopy shows a heterogeneous dispersed phase of morphology. There was poor adhesion between the matrix polymer and glass fibers due to the use of untreated glass fibers. [ABSTRACT FROM PUBLISHER]

The synergetic effect of multi-walled carbon nanotubes (MWCNTs), carbon fiber (CF), and glass fiber (GF) on the static and dynamic mechanical and thermal properties of MWCNTs/epoxy (EP), carbon fiber reinforced polymer (CFRP), and glass fiber reinforced polymer (GFRP)/EP composites were studied. Impact, tensile, and flexural strengths and fatigue cycles of MWCNTs/EP, MWCNTs/CFRP/EP, MWCNTs/GFRP/EP were increased with an increase of MWCNTs content in the epoxy resins. The impact strength of MWCNTs/EP composite is increased dramatically from 4.8 J/M (neat resin) to 12.2 J/M (increased 154.1%) by adding 2.0 phr MWCNTs in the composites. The tensile strength of MWCNTs/CFRP/EP was enhanced from 580.1 MPa (CFRP/EP) to 781.4 MPa (increased 34.7%) by adding 0.5 phr MWCNTs. In addition, the flexural strength of MWCNTs/GFRP/EP was increased from 244.1 MPa (GFRP/EP) to 298.1 MPa (increased 22.16%) by adding 0.75 phr MWCNTs. The fatigue cycles of MWCNTs/GFRP/EP were increased from 959 cycles (GFRP/EP) to 3232 cycles (increased 237%) by adding 2.0 phr MWCNTs. The coefficient of thermal expansion (CTE) of MWCNTs/CFRP/EP was decreased significantly by adding 2.0 phr MWCNTs. The CTE of GFRP/EP had a value of 65.5 ppm/°C by adding 2.0 phr MWCNTs and was lower than that of CFRP/EP. [ABSTRACT FROM AUTHOR]

The design, fabrication, and testing of an epoxy-glass reinforced polymer composite pressure vessel suitable for high-pressure gas storage have been reported. In this study composite pressure vessels are made up of aluminum alloy 6063 seamless liner and glass/epoxy composite reinforcement. The aluminum liner, which is developed by extruded aluminum tube of internal diameter 141mm and wall thickness 4 mm, is subjected to super plastic deformation. Continuous glass fibers impregnated in epoxy resin are wound on the seamless liner by filament winding process. In this work, 10 pressure vessels were manufactured for 3.5MPa service pressure with marginal safety of 3. Four pressure vessels were subjected to cyclic and burst test; the burst pressures were 10.9, 11.0, 11.0, and 13.0 MPa. [ABSTRACT FROM AUTHOR]

Glass fiber (GF)-reinforced biodegradable poly(propylene carbonate) (PPC) composites were prepared by melt blending. The effects of reinforcement on the mechanical, thermal, and morphological properties of the PPC/GF composites were investigated. The mechanical properties of the composites were found to be improved obviously by the incorporation of GF. Experimental results of the thermal properties indicated that the GF addition led to the improvement on the thermal stability of the composites, and that the Vicat softening temperature (VST) of the composites was much higher than that of pure PPC resin. Scanning electron microscopic examination revealed a uniform dispersion of GF within PPC matrix at low GF loading level. It was observed that the GF appeared to be oriented within the PPC matrix to some extent, and there was good interfacial adhesion between GF and PPC matrix. [ABSTRACT FROM AUTHOR]

The flexural, compressive properties of bamboo/glass fiber-reinforced epoxy hybrid composites were studied. The effect of alkali treatment of the bamboo fibers on these properties was also studied. It was observed that both flexural and compressive properties of the hybrid composite increase with glass fiber content. These properties were found to be higher when alkali-treated bamboo fibers were used in the hybrid composites. The elimination of amorphous hemi-cellulose with alkali treatment leading to higher crystallinity of the bamboo fibers with alkali treatment may be responsible for these observations. [ABSTRACT FROM AUTHOR]

The E glass woven fabrics have been used as a reinforcing agent with amine terminated poly(ethylene glycol) benzoate (ATPEGB) modified epoxy as a matrix, for the preparation of fiber reinforced plastic (FRP) composites. The composite materials so obtained were subjected to dynamic mechanical analysis at a fixed frequency of 1 Hz. The volume fraction of glass was about 0.45. The concentration of ATPEGB in the matrix was varied gradually from 0 to 30 phr (phr stands for parts per hundred parts of resin). To investigate the effect of ATPEGB concentration on the dynamic mechanical properties of the composites, it was found that the tan δ peak temperature and storage modulus gradually decrease with incorporation of ATPEGB. However, the tan δ peak value increases up to 10 phr of ATPEGB concentration and decreases thereafter. Flexural strength of the composites increases slightly up to 10 phr of ATPEGB concentration and decreases thereafter. However, the impact strength of the composites increases significantly up to 10 phr of ATPEGB concentration and decreases thereafter. Scanning electron microscope (SEM) analysis of the fracture surface indicates massive plastic deformation in modified epoxy-based composites. [ABSTRACT FROM AUTHOR]

The effects of curing conditions on the mechanical properties of glass fiber reinforced epoxy composites under different fiber prestressing levels were quantitatively studied. The composite samples were prepared with silica particle modified continuous E-glass fibers, epoxy resin matrix, fiber prestressing and step curing processing. Room temperature cured and isothermal high temperature cured composite samples, with the same content and structure, were made to study the difference of three curing conditions on a quantitative level. Based on the test results of flexural, shear, and impact properties of the composite samples, it was found that the step curing procedure generates composite samples with up to 47% and 14% increased properties than room temperature cured and isothermal high temperature cured samples, respectively, when manufactured under the same fiber prestressing level. The possibility of generating an optimum residual stress within the samples during processing is proposed and discussed to explain the contribution of the step curing process to the composite properties. [ABSTRACT FROM AUTHOR]

This study reports the method of recovery of glass fibers from glass/epoxy composites through the solvent method. It is possible to decompose epoxy resin with a yield of more than 99 wt% soluble products in a nitric acid solution (8 M) at 90°C for 5 h. The decomposition rate of epoxy resin increases with an increase in temperature and concentration of acid solution. The glass fibers can be recovered with very little contamination and they have a tensile strength reduction of 3.5% under decomposition conditions of T=70°C, t=250h, C=6M and α=6g/100mL. These fibers can be used as reinforcement to prepare new composites. The interlaminar shear strength (ILSS) of recovered short fiber-reinforced composites produce strength reductions of only 2.5% compared with pristine composites. [ABSTRACT FROM AUTHOR]

Glass-fiber-reinforced unsaturated polyester and epoxy resin composites were exposed to 75°C temperature gradient thermal shock for ten times in different stages of conditioning times. The other lot of short-beam shear specimens were conditioned with a thermal shock of again 75°C temperature gradient for the different cycles. The three-point bend test was performed on the conditioned specimens to evaluate the value of interlaminar shear strength. These conditionings may induce matrix cracking because of large misfit strain. The present experiments aim to study the fiber--matrix debonding effect of thermal shock--thermal fatigue, post-curing hardening phenomena of thermal conditioning, and also the mechanical keying factor of sub-zero conditioning. [ABSTRACT FROM AUTHOR]