How chemical structure changes affect the curing reactions and thermal properties of 2,2 -bis(4-cyanatophenyl) propane (cyanate ester) cured rigid-rod epoxy resins has been studied for biphenol and tetramethyl biphenol epoxies. The formation of an oxazolidinone ring is the dominant curing reaction for biphenol epoxy, whereas the formation of a cyanurate ring is the dominant curing reaction for ...

Polyvinyl ester green composites were synthesized with walnut shell powder (WSP) by in-situ polymerization technique. The green composites have been evaluated for mechanical properties such as tensile strength, tensile modulus and hardness. Sliding wear loss, specific wear rate and coefficient of friction were investigated by using computerized pin-on–disc machine at normal applied loads of 20,...

This study investigates moisture uptake and diffusion mechanisms in thermoset particle-filled composites for anchor applications. Two epoxy-based with low inorganic filler content one vinyl ester-based high were studied. Material characterization revealed particle size distribution, density, the occurrence of pores, composition. Moisture was monitored at different temperatures, relative humidit...

Novel enzyme-mediated synthetic routes were developed to provide a new family of sophorolipid derivatives and glycolopid-based amphiphilic monomers. These compounds are of great interest for their potential use in immunoregulation, as well as for other biological properties. In the present work, an efficient lipase-catalyzed conversion of sophorolipid ethyl ester to (a) the 6'-monoacylated deri...

We aimed to embed silica optical fibers in composites (epoxy vinyl ester matrix reinforced with E-glass unidirectional fibers in mass fraction of 60%) in order to further monitor the robustness of civil engineering structures (such as bridges). A simple system was implemented using two different silica optical fibers (F1-double coating of 172 µm diameter and F2-single coating of 101.8 µm diamet...

Polymers that respond in a productive fashion to their environment are under active development as they offer significant advantages over traditional materials. For example, polymers with the ability to self-heal and recover a significant fraction of their initial properties after being subjected to a damage event are of significant interest. Here we study the effect of healing agent viscosity ...

This paper presents an investigation on energy absorption characteristics of nano-reinforced panels, laminated face sheets and sandwich composites in high velocity ballistic and low velocity punch-shear experiments. The vinyl ester panels were reinforced with 1.25 and 2.5 wt. percent nanoclay and exfoliated graphite platelets. Three different face sheets were manufactured with E-glass, Owens Co...

Composite materials, such as glass fibre reinforced polymers (GFRPs), possess the advantages of high strength and stiffness, low density, as well as manufacturing flexibility; therefore, their potential in replacing conventional materials (such as concrete, aluminium and steel) in building construction has become attractive. One of the major issues that hinder the extensive use of composite str...