Development and characterization of oil palm empty fruit bunch/jute fibres reinforced epoxy hybrid composites.

Kajian ini berkaitan dengan penghasilan komposit hibrid dan komposit hibrid teranyam menggunakan kaedah ‘hand lay-up’. Dalam kombinasi kajian yang unik ini, gentian tandan kosong kelapa sawit (TKKS) dan jut mempunyai perbezaan penting dalam sifat mekanikal dan fizikal telah digunakan sebagai penguat dalam matriks epoksi. Present work deals with the designing of hybrid and woven hybrid composites by hand lay-up method. In this work unique combination of oil palm empty fruit bunch (EFB), and jute fibres having notable differences in mechanical and physical properties have been used as reinforcement in epoxy matrix

Accuracy of computed tomography in differentiating perforated from nonperforated appendicitis, Taking histopathology as the gold standard.

Introduction Acute appendicitis is one of the more common causes of acute abdominal pain. It occurs when the lumen of the appendix is obstructed, leading to inflammation and finally perforation. The preoperative differentiation of perforated from nonperforated appendicitis is important and helpful to define prognosis and determine an adequate therapeutic approach, including consideration for nonsurgical treatment. This study recommends computed tomography (CT), a noninvasive method of investigation, be used frequently in clinically suspected cases of perforated appendicitis in the Pakistani population for better patient outcomes. Objective To determine the diagnostic accuracy of CT in differentiating perforated from nonperforated appendicitis by using histopathology as the gold standard. Material and methods A total of 236 patients with a clinical suspicion of appendicitis were included in this study. CT was performed in Liaquat National Hospital and Medical College. At the time of scanning, intravenous contrast was administered. Histopathology was used as the diagnostic gold standard. CT findings were documented using a proforma. The patient was returned to the referring department and followed after surgery for histopathology. Results Sensitivity, specificity, and positive and negative predictive values, as well as the accuracy of CT in the detection of perforated appendicitis, was 71.4%, 90.7%, 62.5%, 93.6%, and 87.3%, respectively. Conclusion CT findings can be used to select patients with perforated appendicitis for initial nonoperative management

Effect of fiber loadings and treatment on dynamic mechanical, thermal and flammability properties of pineapple leaf fiber and kenaf phenolic composites

This study deals with the analysis of dynamic mechanical, thermal and flammability properties of treated and untreated pineapple leaf fiber (PALF) and kenaf fiber (KF) phenolic composites. Results indicated that storage modulus was decreased for all composites with increases in temperature and pattern of slopes for all composites, having almost the same values of E' at glass transition temperature (Tg). The peak of the loss modulus of pure phenolic composites was shown to be much less. After the addition of kenaf/PALF, peaks were higher and shifted towards a high temperature. The Tan delta peak height was low for pure phenolic composites and maximum for 60% PALF phenolic composites. Cole-Cole analysis was carried out to understand the phase behavior of the composite samples. Thermogravimetric analysis (TGA) results indicated that pure phenolic composites have better thermal stability than PALF and kenaf phenolic composites. Vertical and horizontal UL-94 tests were conducted and showed pure phenolic resin is highly fire resistant. The overall results showed that treated KF composites enhanced the dynamic mechanical and thermal properties among all PALF/KF composites

Effect of natural rubber/epoxidized natural rubber (90/10) on mechanical and thermal properties of linear low density polyethylene.

The effects of blending different amounts of (90/10) natural rubber/epoxidized natural rubber (NR/ENR-50) with metallocene linear low density polyethylene (mLLDPE) on the tensile strength, elongation at yield point, Young’s modulus, hardness and thermal properties were investigated. In this study, N, N-m-phenylenebismaleimide (HVA-2) was used as compatibilizer for the blends. The highest tensile strength was observed in the blend of 90/(9/1) mLLDPE/NR/ENR-50. With increasing mixed rubber content, the tensile modulus is found to decrease continuously, but interestingly the hardness and elongation at yield point is shown to increase. The crystallinity percentage of 10% rubber/mLLDPE was the lowest percentage. The maximum physical crosslinks occur in 90/(9/1) mLLDPE/NR/ENR-50 composite blend. The FTIR showed that the epoxy and double bond groups were found to be absent in all blends indicating thermal stability and compatibility of mLLDPE/rubber blends were improved by addition of 10 and 30% loading of rubber, in the presence of HVA-2 as compatibilizer

A review on potentiality of nano filler/natural fiber filled polymer hybrid composites

The increasing demand for greener and biodegradable materials leading to the satisfaction of society requires a compelling towards the advancement of nano-materials science. The polymeric matrix materials with suitable and proper filler, better filler/matrix interaction together with advanced and new methods or approaches are able to develop polymeric composites which shows great prospective applications in constructions and buildings, automotive, aerospace and packaging industries. The biodegradability of the natural fibers is considered as the most important and interesting aspects of their utilization in polymeric materials. Nanocomposite shows considerable applications in different fields because of larger surface area, and greater aspect ratio, with fascinating properties. Being environmentally friendly, applications of nanocomposites offer new technology and business opportunities for several sectors, such as aerospace, automotive, electronics, and biotechnology industries. Hybrid bio-based composites that exploit the synergy between natural fibers in a nano-reinforced bio-based polymer can lead to improved properties along with maintaining environmental appeal. This review article intended to present information about diverse classes of natural fibers, nanofiller, cellulosic fiber based composite, nanocomposite, and natural fiber/nanofiller-based hybrid composite with specific concern to their applications. It will also provide summary of the emerging new aspects of nanotechnology for development of hybrid composites for the sustainable and greener environment

Flame retardancy and kinetic behavior of ammonium polyphosphate–treated unsaturated polyester/phenolic interpenetrating polymer network.

In this study, the flammability and kinetic behavior of flame retardant unsaturated polyester (UP)/phenolic resin were investigated. The flame retardant ammonium polyphosphate (APP) was used in this research to improve the flame resistance of a UP/phenolic resin interpenetrating polymer network (IPN). The flame resistance of UP improved from none to V-0 classification by adding phenolic resin and APP. Kinetic behavior study of UP, UP/phenolic, and APP-filled UP/phenolic IPN was carried out by the Borchardt and Daniels method. The results indicated that modification of flammable UP resin markedly improved the total heat release volume of UP and the flame retardancy of the IPN network structure was also enhanced

Isolation and characterization of nanocrystalline cellulose from roselle-derived microcrystalline cellulose

Roselle fiber is a renewable and sustainable agricultural waste enriched with cellulose polysaccharides. The isolation of Nanocrystalline cellulose (NCC) from roselle-derived microcrystalline cellulose (MCC) is an alternative approach to recover the agricultural roselle plant residue. In the present study, acid hydrolysis with different reaction time was carried out to degrade the roselle-derived MCC to form NCC. The characterizations of isolated NCC were conducted through Fourier Transform Infrared Ray (FTIR), Transmission Electron Microscopy (TEM), Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM), Dynamic Light Scattering (DLS), Energy Dispersive Spectroscopy (EDS), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC). As evaluated from the performed morphological investigations, the needle-like shape NCC nanostructures were observed under TEM and AFM microscopy studies, while irregular rod-like shape of NCC was observed under FESEM analysis. With 60 min hydrolysis time, XRD analysis demonstrated the highest NCC crystallinity degree with 79.5%. In thermal analysis by TGA and DSC, the shorter hydrolysis time tended to produce NCC with higher thermal stability. Thus, the isolated NCC from roselle-derived MCC has high potential to be used in application of pharmaceutical and biomedical fields for nanocomposite fabrication

Oil palm EFB/Kenaf fibre reinforced epoxy hybrid composites: dimension stability behaviours

In recent years, natural fibres composites have gained increasing interest as a most promising material in different applications due to its attractive properties such as eco-friendly, cost-effectiveness and light weight. Though extensive research has been made on the performance evaluation of natural fibres composite materials, not much data is available on the dimension stability which restricts their use in exterior applications. In this study, hybrid composites were fabricated by hand lay-up technique by reinforcing oil palm empty fruits bunch (EFB) and kenaf fibre mats with epoxy matrix. Experiments are evaluated to study dimension stability that includes water absorption, thickness swelling, density and void content. Increasing the kenaf fibre into EFB composite totally improves the dimension stability of the hybrid composites thus indirectly leads to reduction in voids compared to oil palm EFB composites which is presented lowest percentage of dimension stability and higher void content