Mercerization effect on morphology and tensile properties of roselle fibre

Natural fibres are preferred compared to synthetic fibres because of several advantages such as biodegradable, lightweight, low cost and good mechanical properties. Roselle is one of the plants found to be suitable to be used to produce natural fibres. Although natural fiber reinforced composites are becoming widely used, several weaknesses such as lack of good interfacial adhesion, low melting point and poor resistance to moisture absorption are harmful to its further acceptance. Chemical treatment is a method that can improve the interfacial bonding, stop water absorption, clean the fibre and increase surface roughness. In this study, roselle fibres were immersed in Sodium hydroxide (NaOH) with 3 different concentration (3, 6, and 9%). The results before and after treatment were compared. Scanning electron microscope was used to examine the surface morphology. Tensile properties of roselle fibre were performed to study the tensile properties. Results shows that the higher concentration of NaOH will increase the surface roughness and have higher ability to clean the fibre. For tensile properties, 6% of NaOH give the highest tensile strength. It can be concluded that, 6% of NaOH is the most suitable concentration to clean roselle fibre and while maintaining good tensile properties

Material Characterization Of Roselle Fibre ( Hibiscus Sabdariffa L .)As Potential Reinforcement Material For Polymer Composites

Recently,in line with rising environmental concerns,n 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

The effects of chemical treatment on the structural and thermal, physical, and mechanical and morphological properties of roselle fiber-reinforced vinyl ester 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 fiber-reinforced 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., 39:274–287, 2018. © 2016 Society of Plastics Engineers

Natural fibre filament for Fused Deposition Modelling (FDM): a review

Fused Deposition Modelling (FDM) gets the most attention in development and manufacturing industries. The demand for FDM in industries increases gradually over time and attracts many researchers to enhance the quality of the FDM’s fillers. The most popular filler reinforcements in use are synthetic or carbon fibre. However, these fibres are harmful to the environment. To overcome the issue and replace the current fibres and achieve the bio-composites filler, researchers suggested using natural fibre to replace the synthetic and carbon fibres as the reinforcement, which is also combined with bio-polymer matrix such as thermoplastics as the polymer matrix in FDM’s industries. Many experiments and tests are conducted to prove the capability of the natural fibre as the main material in composite industries. FDM is a world-wide technology that aims to be environmentally friendly, thus, this paper focuses on biodegradable fillers for FDM

Sodium Hydroxide Treatment of Waste Rubber Crumb and Its Effects on Properties of Unsaturated Polyester Composites

This study investigated the optimum NaOH concentration treatment for rubber crumbs that improves adhesion between the polymer matrix and rubber filler in rubber polyester composites. The composite was prepared by mixing rubber crumbs from waste rubber gloves with unsaturated polyester matrix. Rubber crumbs were cryogenically ground from waste gloves and treated with 1%, 4%, 7%, and 10% NaOH (by volume). Treatment with 7% and 10% NaOH provides better wettability and hydrophilicity for rubber as it decreases the surface contact angle by approximately 27%. Higher concentration of NaOH intensively etched the rubber and made the surface rougher with more microcracks, providing a larger surface area for greater polyester coverage and holding the rubber firmly. It also induced more functional groups that increased the rubber surface energy and removed the hydrophobic layer on the rubber. These factors strengthened the interfacial rubber–polyester adhesion, as shown by the SEM micrograph of the tensile fracture which the rubber crumbs adhere well to the polyester matrix. The FTIR analysis of rubber treated with higher NaOH concentration showed a higher peak intensity, which demonstrated more polar groups were generated on the rubber surface. More polar groups created further connections to the polar groups in the polyester matrix, thereby enhancing adhesion between the rubber filler and the matrix

Three-Dimensional Uniaxially Aligned Nanofibre Construct Using Secondary Electrode Assisted Gap Electrospinning

Electrospinning is a simple, versatile, and scalable method of producing polymeric nanofibres from a solution or melt using electric charge. Due to their nanometre-scale diameters, electrospun fibres have been the subject of much study for applications that require a high surface area to volume ratio. However, challenges remain in spatially controlling the deposition of electrospun fibres due to the chaotic nature of electrospinning process. Due to the bending instability, electrospun fibres are typically deposited as random orientated fibres and furthermore, there is no control over the location where the fibres are deposited on the collector. Several techniques to control the deposition of electrospun fibres have been proposed; including the use of modified collectors and by reducing the tip-to-collector distances. Changes in solvent evaporation and the bending instability may reduce stretching of the fibre, resulting in larger diameter fibres. Recently, a new technique for controlling the deposition of electrospun fibres using charged secondary electrodes has been proposed and the results have been promising. In this study, a new approach of directly depositing uniaxially aligned nanofibres onto a holdable structure is demonstrated. The results suggest that the introduction of secondary electrodes charged with time-varying potentials could improve the alignment and distribution of fibres in gap electrospinning process. The new technique would be able to produce fibres for applications which have been previously limited by physical constraint of conventional electrospun fibres

Investigation on Fibre Diameter, Wettability and Tensile Behaviour of Electrospun Polyacrylonitrile Nanofibres

One of the major concerns in membrane distillation technology is membrane wettability. Surface functionalization using superhydrophobic electrospun nanofibre material is thought to be feasible and effective to overcome the issue. However, further understanding on characteristic and mechanical behaviour of electrospun fibres is required. This paper studied the effect of different electrospinning parameters on fibre diameter, wettability, and tensile behaviour of polyacrylonitrile electrospun nanofibres. Polyacrylonitrile in dimethyl-formamide solution of 10 wt.% concentration was electrospun under different applied voltages and electrospinning distances. The characteristic and behaviour of PAN electrospun nanofibres were characterised by using scanning electron microscope, water contact angle method and tensile test. Based on scanning electron micrographs, the average fibre diameters were in the range of nanometre. It was also observed that increasing the applied voltage would increase the fibre diameter, meanwhile, increasing the distance between spinneret and grounded collector would decrease fibre diameter and fibre deposition rate. The average contact angle and the tensile strength of PAN electrospun nanofibres also was determined in this study. The results from this study provide crucial information for the development of new filtration material for membrane distillation

Investigation on fibre diameter, wettability and tensile behaviour of electrospun polyacrylonitrile nanofibres

One of the major concerns in membrane distillation technology is membrane wettability. Surface functionalization using superhydrophobic electrospun nanofibre material is thought to be feasible and effective to overcome the issue. However, further understanding on characteristic and mechanical behaviour of electrospun fibres is required. This paper studied the effect of different electrospinning parameters on fibre diameter, wettability, and tensile behaviour of polyacrylonitrile electrospun nanofibres. Polyacrylonitrile in dimethyl-formamide solution of 10 wt.% concentration was electrospun under different applied voltages and electrospinning distances. The characteristic and behaviour of PAN electrospun nanofibres were characterised by using scanning electron microscope, water contact angle method and tensile test. Based on scanning electron micrographs, the average fibre diameters were in the range of nanometre. It was also observed that increasing the applied voltage would increase the fibre diameter, meanwhile, increasing the distance between spinneret and grounded collector would decrease fibre diameter and fibre deposition rate. The average contact angle and the tensile strength of PAN electrospun nanofibres also was determined in this study. The results from this study provide crucial information for the development of new filtration material for membrane distillation