There are many advantages that polymeric adhesives can offer compared to the more traditional methods of joining such as bolting, brazing, welding, mechanical fasteners, etc. and epoxy adhesives represent the most common type of structural adhesive. When polymerised, epoxy adhesives are amorphous and highly-crosslinked materials and this microstructure results in many useful properties for stru...

In this research, quasi-static penetration and ballistic properties of non-woven kenaf fibres/Kevlar epoxy hybrid laminates with thicknesses ranging from 3.1 mm to 10.8 mm by hard projectile at normal incidence have been experimentally investigated. Hybrid composites were fabricated by hand lay-up technique in a mould and cured at room temperature for 24 h by static load. Hybrid composites cons...

Many recent studies in the development of floating concrete structures focused on a connection system made of modules. In the connection system, the modules are designed to be attached by pre-stressing (PS) while floating on the water, which exposes them to loads on the surface of the water. Therefore, the development of a pre-connection material becomes critical to ensure successful bonding of...

While oat (Avena sativa) has long been known to produce epoxy fatty acids in seeds, synthesized by a peroxygenase pathway, the gene encoding the peroxygenase remains to be determined. Here we report identification of a peroxygenase cDNA AsPXG1 from developing seeds of oat. AsPXG1 is a small protein with 249 amino acids in length and contains conserved heme-binding residues and a calcium-binding...

Low cost composite materials are widely used in civil and structural engineering applications. This project uses EPON to plasticize a commonly used resin, epoxy resin to lower the cost of the composite and to find out the mechanical and thermal properties of the plasticized epoxy resin to see if it is suitable for the said applications. Three point bending tests were carried out to evaluate the...

[3H]Squalene 2,3(S);22(S),23-dioxide was prepared by incubation of [3H]mevalonate with S10 rat liver homogenate in the presence of 4,4,10 beta-trimethyl-trans-decal-3 beta-ol, a specific inhibitor of oxidosqualene cyclase (EC 5.4.99.7). Aerobic incubation of [3H]squalene 2,3(S);22(S),23-dioxide with S10 rat liver homogenate affords 24(S),25-epoxycholesterol with an efficiency comparable to that...

Molecular Dynamics simulations are used to study cross-linking of an epoxy polymer. OPLS force field parameters are used for modeling a 2:1 stoichiometric mixture of epoxy resin and the cross-linking agent. The model has 17,928 united atoms and a static cross-linking method is used along with molecular minimization and molecular dynamics techniques to achieve two different cross-link densities....

Exposure to extended periods of sub-Tg temperatures causes physical changes in the molecular structure of epoxy resins and epoxy-based materials to occur. These physical aging mechanisms include the reduction in free volume and changes to the molecular configuration. As a result, mechanical, thermodynamic, and physical properties are affected in ways that can compromise the reliability of epoxy...

Optical microscope images of graphite oxide (GO) reveal the occurrence of fault lines resulting from the oxidative processes. The fault lines and cracks of GO are also responsible for their much smaller size compared with the starting graphite materials. We propose an unzipping mechanism to explain the formation of cracks on GO and cutting of carbon nanotubes in an oxidizing acid. GO unzipping ...

For the first time, repeatable self-healing was achieved in a cross-linked epoxy polymer by incorporating 2-ethyl-4-methylimidazole (24-EMI) into the matrix as a latent polymerization initiator. Upon material damage and infiltration of liquid EPON 8132 epoxy monomer healing agent into the crack plane, polymerization occurs in the damaged region with a moderate application of heat in the presenc...