This paper investigates the physical, thermal, mechanical and morphological properties of betel nut husk fibre, in order to assess their suitability as lignocellulosic reinforcement for polymer composites. Betel nut husk (BNH) fibres of three different stages of maturity were evaluated to study the effect of fibre maturity on the thermal, physical and mechanical properties of BNH fibre. The thermal stability of BNH fibre was studied using the thermogravimetric analysis (TGA) technique. It was found that the thermal stability of the BNH fibre is influenced by the maturity of the BNH fibre due to the different amounts of cellulose, hemicellulose, lignin, and moisture in the BNH fibre at each stage of maturity (raw, ripe, matured). The BNH fibres showed decrease in fibre length and fibre diameter, and increase in density with the increase in fibre maturity. SEM micrographs of BNH fibre surface revealed the existence of rough and perforated surface of BNH fibre. Whereas, the cross-sectional of the BNH fibre showed that the raw BNH fibres were observed with bigger lumen, whilst ripe BNH fibre exhibits a slightly smaller and elongated lumen. In contrast, matured BNH fibre showed more compact structures instead of hollow-like lumen structures. In terms of mechanical properties, the BNH fibre tensile properties were found to be comparable to coir and kenaf fibre, which have been widely used as reinforcement in polymer composites.

Roselle fiber is a type of natural fiber that can potentially be used as a reinforcement material in polymer composites for different applications. This study investigated the chemical, physical, thermal, mechanical, and morphological characteristics of roselle fiberreinforced vinyl ester subjected to different fiber treatments. The roselle fiber was treated with alkalization and a silane coupling agent, and samples were prepared using the hand lay-up method. Treated roselle fiber significantly enhanced most of the properties of vinyl ester biocomposites compared with an untreated biocomposite. The results revealed that alkalization and silane treatment of the fiber changed its chemical properties. The treated fiber improved water repellence behavior of the roselle fiber-reinforced vinyl ester compared with the untreated fiber. Use of a silane coupling agent was determined as the best chemical treatment for the water absorption effect. Thermogravimetric analysis (TGA) demonstrated that alkalization-treated fiber had improved thermal stability; however, the opposite result was obtained with the silane-treated fiber. The morphological examination of treated and untreated roselle fiber-reinforced vinyl esters showed a good fiber adhesion between the treated fiber and the matrix, and less fiber pull-out from the matrix was observed. This observation provides good indication of the interfacial interlocking between the fiber and the matrix, which improved the tensile properties of the composites. In contrast, the impact results revealed that the treated fiber had a decreased impact energy compared with the untreated fiber. POLYM. COMPOS.,

No abstract

Recently, in line with rising environmental concerns, researchers are now replacing synthetic fibres with natural ones as the main component in composites. Natural fibres are preferred to synthetic fibres because of several advantages such as biodegradable, light weight, low cost and good mechanical properties. Roselle is one of the plants found to be suitable to be used to produce natural fibres. In this work, we analysed the physical, thermal and mechanical characteristics of roselle fibre. Roselle fibre has good physical properties which lead to the dimensional stability of the composite product. The result obtained indicated that the moisture content of roselle fibre is 10.9%, while water absorption is 286.5%. Thermal gravimetric analysis (TGA) was conducted to understand the thermal stability of roselle fibre at high temperature. The results show that the initial degradation of roselle fibre starts at 225 °C and completes the decomposition of the lignocellulosic component at 400 4C. A tensile test was conducted to investigate the mechanical properties of roselle fibre. The tensile strength of roselle fibre is 130-562 MPa. On the basis of the properties of roselle fibres obtained, we concluded that roselle fibre is one of the good natural fibres that can be used as reinforced material for the manufacturing of polymer composites for different applications, while at the same time saving the cost required to manage the agro waste.