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In this work, thermal stability, flame retardance and smoke suppression characteristic of kenaf (KF) and oil palm empty fruit bunch (EFB) filled composites were studied. Polylactic acid (PLA), polystyrene (PS) and liquid epoxy were used as the matrices. Aluminum trihydrate (ATH) flame retardant (FR) ranging from 5 - 15% was incorporated into the composites to investigate the effects of ATH concentration on flammability and smoke intensity. The thermoplastic composites were prepared through solvent dissolution followed by compression molding. The thermoset composite was produced using a vacuum press machine. Vertical Bunsen burner test, Ringelmann smoke chart, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and tensile test were performed to investigate the flame retardancy, smoke suppression properties, thermal stability, morphology and mechanical properties of the composites. The results show that incorporation of ATH can greatly increase the flame retardance and smoke suppression of the materials. Their mechanisms were discussed. SEM micrographs of post combustion ATH incorporated samples revealed that the morphology of char residue consisted of numerous pores in the polymer bulk. These porous-like structures have shown to be beneficial in retarding flame. [ABSTRACT FROM AUTHOR]

Cellulose nanocrystals (CNCs) from kenaf core were prepared using acid hydrolysis method while graphene oxide (GO) were synthesized from modified Hummer's method. Low filler content composites films of CNC (0.1 - 0.4 wt.%) and GO (0.1 - 0.6 wt.%) in PLA films were prepared separately using solution casting method. From tensile test, it was found that optimum modulus increment were obtained for 0.2 wt.% CNCs and 0.4 wt.% GO in PLA which gave an increment of 125% and 40%, respectively. Only a small amount of CNCs are needed to improve the tensile properties of PLA. From microscopic observation of fractured surface at higher filler contents, CNC agglomerates tend to form which serves as void nucleating agent during plastic deformation due to poor interfacial properties while GO agglomerates cannot be observed in composites. Improved mechanical properties were not due to increment of crystallinity in PLA but reinforcement from fillers. [ABSTRACT FROM AUTHOR]

During free surface moulding processes such as thermoforming and blow moulding, heated polymer materials are subjected to rapid biaxial deformation as they are drawn into the shape of a mould. In the development of process simulations, it is therefore essential to be able to accurately measure and model this behaviour. Conventional uniaxial test methods are generally inadequate for this purpose and this has led to the development of specialised biaxial test rigs. In the present study, the results of several programmes of biaxial tests conducted at Queen's University are presented and discussed. These have included tests on high impact polystyrene (HIPS), polypropylene (PP) and aPET, and the work has involved a wide variety of experimental conditions. In all cases, the results clearly demonstrate the unique characteristics of materials when subjected to biaxial deformation. PP draws the highest stresses and it is the most temperature-sensitive of the materials. aPET is initially easier to form but exhibits strain hardening at higher strains. This behaviour is increased with increasing strain rate but at very high strain rates, these effects are increasingly mollified by adiabatic heating. Both aPET and PP (to a lesser degree) draw much higher stresses in sequential stretching showing that this behaviour must be considered in process simulations. HIPS showed none of these effects and it is the easiest material to deform. [ABSTRACT FROM AUTHOR]