Characterization and Properties of Natural Fiber Polymer Composites: A Comprehensive Review

Emerged in the middle of 20th century, composite materials are now one of the hotspot research topics in the modern technology. Their promising characteristics make them suitable for enormous applications in industrial field such as aerospace, automotive, construction, sports, bio-medical and many others. These materials reveal remarkable structural and mechanical properties such as high strength to weight ratio, resistance to chemicals, fire, corrosion and wear; being economical to manufacture. Herein, an overview of composite materials, their characterization, classification and main advantages linked to physical and mechanical properties based on the recent studies are presented. There, were presented the conventional manufacturing techniques of composite and their applications. It was highlighted the tremendous need to discovery new generation of composites that should incorporate the synthetic or natural materials by implementing new efficient manufacturing processes. In the combination of matrix and reinforcement materials, the use of natural materials as constituent are compulsory in order to obtain a complete material degradable as environmentally friendly.

Recent progress of reinforcement materials: a comprehensive overview of composite materials

Adhesion and Adhesives Edited by Dr. R. Houwink and Dr. G. Salomon. Vol. 1: Adhesives. Second, completely revised edition. Pp. xvi + 548. (Amsterdam, London and New York: Elsevier Publishing Company, 1965.) 135s.

/pdf/adhesion-and-adhesives-1r2k52nrht.pdf

Adhesion and Adhesives

Recently published research indicates that natural fibre based polymer composites have limited applications in advanced structural systems due to their low impact performance. However, natural fibres have great potential for reducing the product weight, lowering material cost, and renewability. Hybrid composites made from a combination of natural/synthetic fibres, natural/natural fibres, or synthetic/synthetic fibres are also receiving attention from both researchers and the industry for structural applications owing to the tailored mechanical and impact properties of these materials. The hybridisation process is one of the paramount and more efficient ways to strengthen and improve the performance of composite materials. This review paper examines the impact properties of hybrid composites manufactured with the aim of improving their structural characteristics, and in particular, is focused on the impact resistance and penetration behaviour of hybrid composites reinforced with natural and synthetic fibres as well as their suitability for modern structural applications.

Impact behaviour of hybrid composites for structural applications: a review

The effects of hot axisymmetric compression to break down the primary carbide network of the H23 tool steels were studied. This current study only focused on one strain rate of 0.01 s -1 . The samples were deformed at 3 different temperatures (1000, 1050 and 1100 o C) with solutioning temperatures 1100 and 1250 o C, respectively. Afterwards, the samples were cooled by water quenching. The techniques used in this current study for investigation were the optical and electron microscopes and Vickers hardness test. The results show that hot axisymmetric compression had broken down the primary carbide network in the direction perpendicular to the compression axis and the carbides became finer. Although the highest hardness (274 HV) was achieved after solutioning at 1250 o C, followed by deformation at 1000 o C, however the microstructure analysis indicated that the optimum hot axisymmetric compression condition was solutioning at 1250 o C and deformation at 1000 o C.

Advanced Materials Research

In this study, the effect of bond thickness upon shear strength and fracture toughness of epoxy adhesively bonded joint with dissimilar adherents was addressed. The bond thickness, t between the adherents was controlled to be ranged between 0.1 mm and 1.2 mm. Finite element analyses were also executed by commercial ANSYS 11 code to investigate the stress distributions within the adhesive layer of adhesive joint. As a result, shear strength of adhesive joint reduces with increasing bond thickness. The strength of shear adhesive joint was also depended on elastic modulus of adherent. Moreover, the failure of dissimilar adherents bonded shear joint originated at a location with critical stress-y which was the interface corner of ALYH75/epoxy. In the case of shear adhesive joint with an interface crack, the fracture also occurred at the ALYH75/epoxy interface even in the steel-adhesive-aluminum (SEA) specimens. Fracture toughness, Jc of aluminum-adhesive-steel (AES) joints was similar to those of SES and demonstrates strong dependency upon bond thickness. Furthermore, the interface crack in SEA specimen has relatively large fracture resistance if compared to those in AES specimen. Finally, Kc fracture criterion was found to be appropriate for shear adhesive joints associated with adhesive fracture.

Fracture Characteristics of Shear Adhesive Dissimilar Joint

Water ageing effect on the strength of adhesively bonded joints

This paper presents the electromagnetic interference (EMI) shielding effectiveness (SE) investigation of carbon black filled polyester composites. The composition of the polymer composite ranging from 4, 6, 8 and 10wt % of carbon black to unsaturated polyester resin was prepared. Two types of carbon black were used in this project, carbon black derived from water hyacinth and commercially available activated carbon black. The S (scattering)-parameters (S11 and S21) of polyester composites were measured and compared between the two types of carbon black; carbon black derived from water hyacinth and activated carbon black. The shielding effectiveness was determined from measured S11 and S21 parameters. It was observed that the shielding effectiveness of the composites is frequency dependent and filler loading dependent. According to the results, the contribution of absorption to shielding effectiveness of both carbon blacks is greater than 83 % at 3 GHz. The analyzed results showed that the percentage of shielding effectiveness of polyester composite reinforced with naturally derived carbon black is similar to those with activated carbon black. The result also showed that the contribution of absorption to the shielding effectiveness was larger than that of reflection. This research suggests that polyester composite with carbon black derived naturally from water hyacinth can be used as a replacement for the commercially available activated carbon black as a shielding material in medical applications.

Electromagnetic Interference (EMI) Shielding Effectiveness (SE) of Unsaturated Polyester Resin with Carbon Black Fillers

This paper describes the investigation of the effect on the Wireless Local Area Network (WLAN) signals due to fixed and non-fixed variables in indoor environment The measurement system consisted of a spectrum analyzer and a log-periodic antenna Line-of-sight (LOS) and non-line-of-sight (NLOS) propagation (in furnished rooms) were discussed All the measurement sites mentioned in this paper are located in the Division of Information Technology at Universiti Putra Malaysia The furnished rooms included a teaching laboratory, a computer laboratory, and an operating office plus a server room The effects of the various types of materials at the measurement sites also are described here

The effect of physical changes in a furnished indoor environment on Wireless Local Area Network (WLAN) signals

The development of microelectronic industry has made solder joints failure a major reliability issue. From literature, many researchers have identified that intermetallic compounds (IMC) layer contribute greatly to the fracture of solder joint. This paper presents a finite element modeling of solder butt joints IMC layer failure based on displacement extrapolation method (DEM). Conceptual study on single edge crack of IMC solder joints is presented. A FE analytical model is proposed to be used in difference range of crack length to understand the fracture behavior of solder joint of IMC layer. The simulation results show that soldering material become less tough if greater crack length is present in the joint. It also seen that the thicker IMC has slightly reduced the stress intensity factor on the crack tip but the change from solder to IMC layer decrease the solder joint fracture toughness.

M.S. Abdul Majid

Papers

Fracture Characteristics of Shear Adhesive Dissimilar Joint

Water ageing effect on the strength of adhesively bonded joints

Electromagnetic Interference (EMI) Shielding Effectiveness (SE) of Unsaturated Polyester Resin with Carbon Black Fillers

The effect of physical changes in a furnished indoor environment on Wireless Local Area Network (WLAN) signals

Fracture behavior of intermetallic compound (IMC) of solder joints based on finite elements’ simulation result