H. Ku

A critical review on the manufacturing processes in relation to the properties of nanoclay/polymer composites

Nanoclay/polymer composites can be prepared by various processing techniques such as solution process, in-situ polymerization and melt blending. Each technique has an influence on the final characteristics and properties of the composites. In this study, different processing techniques are reviewed in order to study the relationship between these techniques and the final characteristics and properties of nanoclay/polymer composites, i.e., the final structure formation, rheological perfection, thermomechanical and thermal properties. Thermodynamic and physical properties such as glass transition temperature, equilibrium melting point and crystallization temperature are also discussed. Moreover, the effect of ‘nanofiller’ on crystallinity phases of polymeric resin from a processing technique perspective is briefly reviewed to clarify the role of polymer-nanoclay interactions and nanoclay dispersion on the elastic-viscoelastic behaviour of composites. The current review concluded that altering processing technique (type and/or parameters) highly influences the final nanostructure morphology as well as the thermodynamic and mechanical properties of nanoclay/polymer composites.

Curing Vinyl Ester Particle-reinforced Composites using Microwaves

Composites made from vinyl ester resins suffer considerable shrinkage during curing and after solidification. This project attempts to reduce the shrinkage of the components by shortening the curing time of the resins using penetrating microwave energy. The amount of initiator used to initiate polymerization and the input power of microwave energy are varied to obtain an optimum combination of these parameters for minimum shrinkage of the composite components. The original contribution of this paper is to have flyash particulate-reinforced vinyl ester resins cured under microwave conditions with a view to reducing the shrinkage of the composites during curing; this aim is fully achieved.

Final year engineering projects in Australia and Europe

The paper starts by emphasising that final year engineering projects are regarded important in the training and education of professional engineers in Australia and Europe. The sources of projects available to students were also mentioned. Some Australian universities insist on individual projects but some not, each with their own reasons. However, it can be argued that all European universities run individual projects. In most cases, whether it is in Australia or Europe, the total load for final year engineering projects is about 6.25% of the load of engineering programmes. Assessment methods were also described. They were all different whether in Australia or Europe but not very significant. It was discovered that literature reviews, oral presentations and written reports or dissertations were important elements in the assessment schemes. Many university staff, in both continents, encouraged students to publish their work in international conferences and journals if the originality of the projects was high. It can be argued that the individual project is most effective in learning outcome; however, the cost involved is also very high and its sustainability in smaller universities in Australia is in doubt.

A Simplified Empirical Model for Prediction of Mechanical Properties of Random Short Fiber/Vinylester Composites

This article discusses a simplified approach to analyze mechanical properties of randomly distributed short fiber composites. Mechanical properties of three different randomly oriented short fiber composites, cotton, nylon, and aluminium with vinylester resins, were experimentally investigated. The analytical results were compared with experimental results and a very good correlation was found. Further, the experimental results and the predictions showed that the strength of the composites is less than the strength of the matrix material, for all three composites tested.

Remote Access Laboratories in Australia and Europe.

Remote access laboratories (RALs) were first developed in 1994 in Australia and Switzerland. The main purposes of developing them are to enable students to do their experiments at their own pace, time and locations and to enable students and teaching staff to get access to facilities beyond their institutions. Currently, most of the experiments carried out through RALs in Australia are heavily biased towards electrical, electronic and computer engineering disciplines. However, the experiments carried out through RALs in Europe had more variety, in addition to the traditional electrical, electronic and computer engineering disciplines, there were experiments in mechanical and mechatronic disciplines. It was found that RALs are now being developed aggressively in Australia and Europe and it can be argued that RALs will develop further and faster in the future with improving Internet technology. The rising costs of real experimental equipment will also speed up their development because by making the equipment remotely accessible, the cost can be shared by more universities or institutions and this will improve their cost-effectiveness. Their development would be particularly rapid in large countries with small populations such as Australia, Canada and Russia, because of the scale of economy. Reusability of software, interoperability in software implementation, computer supported collaborative learning and convergence with learning management systems are the required development of future RALs.

Fracture Toughness of Phenol Formaldehyde Composites Reinforced with E-spheres

A commercial phenol formaldehyde-based resole thermosetting resin supplied by Borden Chemical Australia Pty., was reinforced with ceramic-based fillers (SLG) to increase its fracture toughness. This is the second study of the same series. By testing fracture toughness and viscosity at a range of filler addition levels, the optimal addition of SLG was determined in terms of workability, cost, and performance. The composites obtained were post-cured in a conventional oven as in the previous study. The original contributions of this article include lowering the cost of the composite (35wt% of SLG) by 50% but at the same time the fracture toughness was reduced only by 20% (compared to the neat resin), and increasing the fire resistance of the resins tremendously. It was also found that the values of fracture toughness of the samples in this study were higher than those obtained in the previous study when the percentage by weight of SLG varies from 0 to 35%. The shapes of the plots of fracture toughness against percentage by weight of SLG were also different. The possible reasons for the differences were explained.

Relationship Between Electrical and Mechanical Loss Tangents of SLG Reinforced Phenolic Composites: Pilot Study

The mechanical properties of ceramic microspheres (SLG) reinforced phenolic resin composites have been measured and evaluated in earlier studies. This basic but critical and important data has created interest in the relevant industry in Australia. This study is therefore carried out to measure and evaluate the dielectric and mechanical properties of the composites with a view to benefit the relevant industry. The relationship between the two properties will also be studied. The original contributions of this article are that samples post-cured in conventional ovens have higher electrical loss as well as mechanical loss than their counterparts post-cured in microwaves. The storage modulus of all samples post-cured conventionally is higher than its counterpart. This is in line with the fact that it is a softer material with lower glass transition temperature. They also have higher mechanical loss tangent as well as loss modulus. For all percentages by weight of SLG, the glass transition temperature for the microwave cured sample was higher and the composite was stiffer; the opposite was true for the conventionally cured sample.

Tensile tests of phenol formaldehyde SLG reinforced composites: pilot study

Phenol formaldehyde was filled with Envirospheres SLG to increase the strength and impact toughness of the composite for structural applications by the Centre of Excellence in Engineered Fiber Composites (CEEFC), University of Southern Queensland (USQ). In order to reduce costs, the Centre wishes to fill as much SLG as possible subject to maintaining sufficient strength and impact toughness of the composites in structural applications. This project varies the percentages by weight of the SLG in the composites which are then subjected to tensile tests. The results show that composite with 10% by weight of the SLG produces the highest yield, tensile strengths and Youngs modulus combined with a reasonable fluidity for casting.

Flexural Tests of Phenol Formaldehyde and Slg Composites: Pilot Study

Phenol formaldehyde was filled with Envirospheres slg to increase the strength of the composite for structural applications by a research center on composites, University of Southern Queensland (USQ). In order to reduce costs, the center wished to fill with as much slg as possible, subject to maintaining sufficient strength of the composites in structural applications. This project varied the wt% of the slg in the composites which were then subjected to flexural tests. The results showed that composite with 25 wt% of the slg produced the highest flexural strength and Young’s modulus combined with a reasonable fluidity for casting; the highest flexural strain was achieved when the slg was 10 wt%.

Contrasts on Fracture Toughness and Flexural Strength of Varying Percentages of SLG-reinforced Phenolic Composites

Many previous studies had reported the improvement in the mechanical properties of vinyl ester resin reinforced with SLG. Among these material properties, fracture toughness and flexural properties are important material characteristics. This article investigates the relationship between these two sets of material properties in envirospheres (SLG)-reinforced phenolic composites. The material properties of the phenolic resin composites containing different percentage by weight of SLG are experimentally measured using the short bar method and the three-point test. The findings indicated that the PF/E-SPHERES (30%) constitute the best compromise with respect to cost, fracture toughness, and flexural strength. It is hoped that the discussion and results in this work would not only contribute towards the development of SLG-reinforced phenolic composites with better material properties, but also be useful for the investigations of fracture toughness and flexural strength in other composites.