Natural fiber such as bamboo fiber, oil palm empty fruit bunch (OPEFB) fiber, kenaf fiber, and sugar palm fiber-reinforced polymer composites are being increasingly developed for lightweight structures with high specific strength in the automotive, marine, aerospace, and construction industries with significant economic benefits, sustainability, and environmental benefits. The plant-based natural fibers are hydrophilic, which is incompatible with hydrophobic polymer matrices. This leads to a reduction of their interfacial bonding and to the poor thermal stability performance of the resulting fiber-reinforced polymer composite. Based on the literature, the effect of chemical treatment of natural fiber-reinforced polymer composites had significantly influenced the thermogravimetric analysis (TGA) together with the thermal stability performance of the composite structure. In this review, the effect of chemical treatments used on cellulose natural fiber-reinforced thermoplastic and thermosetting polymer composites has been reviewed. From the present review, the TGA data are useful as guidance in determining the purity and composition of the composites’ structures, drying, and the ignition temperatures of materials. Knowing the stability temperatures of compounds based on their weight, changes in the temperature dependence is another factor to consider regarding the effectiveness of chemical treatments for the purpose of synergizing the chemical bonding between the natural fiber with polymer matrix or with the synthetic fibers.

This purpose of this paper was to reveal characteristics of a composite structure containing carbon fiber as a reinforcement and blended synthetic epoxy/bio-epoxy derived from crude jatropha oil as resin and compared with fully synthetic epoxy. The composite structure was prepared by the vacuum-assisted resin transfer molding technique and was left to cure for 24 h at room temperature. Both were characterized for their thermal, chemical, and flammable characteristics. The incorporation of jatropha bio-epoxy into the matrix significantly improved the thermal stability between 288–365 °C as obtained by thermogravimetric analysis (TGA) test. Dynamic mechanical analysis (DMA) curves showed slight diminution of performances and Tg from DMA tests confirmed well with the trend of Tg obtain by differential scanning calorimetry (DSC) curves. On the other hand, the flammability property was rated horizontal burning (HB) which was the same as the fully synthetic composite, but the duration to self-extinguish was halved for the composite with jatropha bio-epoxy. Fourier transform infrared attenuated total reflectance (FT-IR/ATR) was conducted to determine the difference of functional groups’ spectrum due to bonding type existing on both specimens. Overall, the composite specimen with blended bio-epoxy exhibited better thermal stability, comparable flammability characteristics, and performances. The aim of this paper was to introduce bio-based epoxy as a potential alternative epoxy and to compete with synthetic epoxy so as to minimize the footprint of non-renewable composite.

Cutting fluid is a well-known as one of an important element in machining process. However, the consumption of mineral oils as cutting fluid has been raising concern due to worldwide interest in environmental and health matters. The application of vegetable-oil based lubricant is seen can overcome the problem but requires a research study about the machinability. This research paper represents the machinability of using several possible vegetable oils as cutting fluid in term of chip formation and tool wear during drilling operation on stainless steel, AISI 316. In particular, the performance of the vegetable oils; palm, sesame, olive and coconut oils were compared under minimum quantity lubrication (MQL) technique. The result reported that the coconut oil indicates the best machinability in term of highest and uniform chip thickness and least wear on the drill bit under same condition with others. These performances are followed by palm, olive and sesame oil. In additional, the viscosity measurement indicates that coconut oil has the lowest value which can possesses better fluidity and faster cooling capacity than other oils. Overall, coconut oil is recommended as viable alternative lubricants during drilling of stainless steel.

No abstract

No abstract

No abstract

No abstract

The common problems that faced during machining process are high cost due to increase tool wear, reduced quality of product due to poor surface finish and widely use of mineral and synthetic oils as metal working fluids that are recognized as harmful to both environment and health of the machine operator. Vegetable oil is renewable oil that possesses good biodegradability and lubricating ability which has potential to replace synthetic oil and mineral oil as environmental friendly cutting fluid if proper researches have been conducted. The aim of this experimental study is to determine and optimize the best additive to be added to the vegetable oil to improve its machinability. Types of additives selected in this experimental study are Propyl Gallate (PG), Boric Acid (BA) and Polydimethylsiloxane (PDMS). The experimental study uses a Taguchi design methodology in designing the experiment. Three different factors at three different levels are selected to conduct the experiment such as feed rate (mm/rev), cutting speed (m/min) and depth of cut (mm). The effect of tool wear and surface roughness during turning of mild steel (AISI 1040) were statistically evaluated using wear area analysis method and analysis of variance (ANOVA) method, respectively. It is observed that sunflower oil added with 3% Boric Acid is the most effective cutting fluid to reduce the tool wear while sunflower oil added with 3% Propyl Gallate is the most effective cutting fluid to reduce the surface roughness.