The progress of Palm Oil Mill Effluent (POME) treatment in meeting with the regulation and standard stipulated by the Environmental Authority always been a major issue in Palm oil industries. To occupy the palm oil world market demand, palm oil industry needs to produce more than the market demand to supply necessity. Currently, South East Asia country such as Malaysia, Indonesia and Thailand rank the top country with the largest production of palm oil in the world. However, the increasing demand for the palm oil has resulted in even massive waste especially palm oil mill effluent (POME). Direct discharge of POME will adversely affect the environment. In 2011, 53 million tonnes metric of palm oil produced and 89% of this production comes from Malaysia and Indonesia. Thailand, however, used the palm oil solely for domestic usage. Since POME has been declared among the major source of pollution, a great deal of research and development including application devoted to enhance the current treatment method for POME to consistently meet the proposed stringent regulatory requirement by environmental authority. Conventional treatment such as ponding system is the most commonplace method to treat POME through the application of ponding system which is include aerobic and anaerobic treatment. Recently, the alternative methods such as coagulation, flocculation, adsorption, advanced oxidation process (AOP) and membrane technology to treat POME has shown a promising result compared to the conventional method.

Palm oil industry in South East Asia and the effluent treatment technology—A review

Cochin University of Science and Technology,S.N.M College, NIT Calicut,Central Power Research Institute,M.G University

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Dynamic mechanical analysis of binary and ternary polymer blends based on nylon copolymer/EPDM rubber and EPM grafted maleic anhydride compatibilizer

Dynamic mechanical analysis (DMA) was used to study the miscibility and various transitions (α, β, and γ) in binary blends of ethylene vinyl acetate copolymer (EVA) with low-density polyethylene (LDPE) and high-density polyethylene (HDPE). Addition of a rubbery phase, such as EVA, reduced all the transition temperatures. A peak broadening of tan δ was observed with increasing EVA content in the blends. This can be explained by the observed reduction of the crystallinity of the systems. The presence of a single transition peak in the region of glass transition temperature (Tg) has indicated that the blends were miscible. However, morphological investigation by scanning electron microscopy (SEM) revealed the features of a two phase system in which the EVA domains would be dispersed in the polyethylene (PE) phase. The results have demonstrated that DMA is not sensitive enough to study the miscibility of polymeric blends with a similar backbone structures (such as PE and EVA) in view of the small difference in their Tg. For such blends, therefore, the use of direct observations, such as microscopic examinations is necessary. © 2004 Wiley Periodicals, Inc. Adv Polym Techn 23: 307–315, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20019

Dynamic mechanical properties and morphology of polyethylene/ethylene vinyl acetate copolymer blends

The purpose of this review is to describe the various aspects of pressure-sensitive adhesives prepared from natural rubber. Pressure-sensitive adhesives (PSAs) adhere instantaneously to a variety of surfaces upon application of slight pressure and can be obtained using different technologies. PSAs are materials that develop tack for low pressures and short contact times. There are number of factors affecting the adhesion property of natural rubber based pressure-sensitive adhesives. In this review, factors affecting adhesion property such as tack, peel and shear are examined in light of their relevance to adhesion in addition to measurement methods of each of the three major adhesion properties. This review paper covers the work being carried out from the last 20 years in the field of natural rubber based pressure sensitive adhesives.

Natural Rubber-Based Pressure-Sensitive Adhesives: A Review

The effects of the blend ratio, reactive compatibilization, and dynamic vulcanization on the dynamic mechanical properties of high-density polyethylene (HDPE)/ethylene vinyl acetate (EVA) blends have been analyzed at different temperatures. The storage modulus of the blend decreases with an increase in the EVA content. The loss factor curve shows two peaks, corresponding to the transitions of HDPE and EVA, indicating the incompatibility of the blend system. Attempts have been made to correlate the observed viscoelastic properties of the blends with the blend morphology. Various composite models have been used to predict the dynamic mechanical data. The experimental values are close to those of the Halpin–Tsai model above 50 wt % EVA and close to those of the Coran model up to 50 wt % EVA in the blend. For the Takayanagi model, the theoretical value is in good agreement with the experimental value for a 70/30 HDPE/EVA blend. The area under the loss modulus/temperature curve (LA) has been analyzed with the integration method from the experimental curve and has been compared with that obtained from group contribution analysis. The LA values calculated with group contribution analysis are lower than those calculated with the integration method. The addition of a maleic-modified polyethylene compatibilizer increases the storage modulus, loss modulus, and loss factor values of the system, and this is due to the finer dispersion of the EVA domains in the HDPE matrix upon compatibilization. For 70/30 and 50/50 blends, the addition of a maleic-modified polyethylene compatibilizer shifts the relaxation temperature of both HDPE and EVA to a lower temperature, and this indicates increased interdiffusion of the two phases at the interface upon compatibilization. However, for a 30/70 HDPE/EVA blend, the addition of a compatibilizer does not change the relaxation temperature, and this may be due to the cocontinuous morphology of the blends. The dynamic vulcanization of the EVA phase with dicumyl peroxide results in an increase in both the storage and loss moduli of the blends. A significant increase in the relaxation temperature of EVA and a broadening of the relaxation peaks occur during dynamic vulcanization, and this indicates the increased interaction between the two phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 2083–2099, 2003

Dynamic mechanical behavior of high‐density polyethylene/ethylene vinyl acetate copolymer blends: The effects of the blend ratio, reactive compatibilization, and dynamic vulcanization

Mechanical properties and fracture of melt-blended poly(vinyl chloride) (PVC) and epoxidized natural rubber (ENR) having 50 mol % epoxidation level are studied at different compositions. The effect of blend ratio on tensile strength, tear strength, elongation at break, tension set after failure, and hardness are determined. The stress-strain behaviour of low ENR blends exhibits yielding and necking, whereas that of high ENR blends exhibits soft elastomeric deformation. At higher compositions of ENR, plots of tensile strength, tear strength, and hardness against blend composition are concave in nature; and plots of the elongation at break deviate markedly from the additive value with a pronounced maximum occurring at the 70wt% composition of ENR. The scanning electron microscopic examination of fracture surfaces of blends does not show any features of phase separation of ENR or PVC. The tensile fracture surface of rigid PVC exhibits partially fused particle structures of PVC and that of blends exhibits features of shearing and horizontal discontinuous striations. The torn surface of rigid PVC shows evidence of intrinsic crazing and that of blends shows features of shear fibrils, vertically changed discontinuous striations, steps, and unstable and stable tear fronts.

Miscible blends from rigid poly(vinyl chloride) and epoxidized natural rubber

A study on the tensile and tear failure of miscible blends of plasticized poly (vinyl chloride), PVC, and epoxidized natural rubber (ENR) was carried out. Fractographs were taken in a scanning electron microscope in order to obtain an insight into the failure mechanism of the samples. It was found that low ENR blends failed by shearing in tensile testing, and they exhibited irregular stick-slip deformation and characteristics like vulcanizates in tear testing. Blends of plasticized PVC and ENR were more flexible than the individual components. As a result of the geometrical effect the tear fracture surface has rougher features than the tensile fracture surface. Sinusoidal wavy tear patterns in the form of a typical sine wave and rectified half sine wave of the fracture surface are characteristic features of tear resistant non-vulcanizates of rubber-like materials. Moreover, the study revealed that there were no features of phase separation of PVC and ENR due to incompatibility at any of the fracture surfaces examined.

S. K. Sanyal

Papers

Miscible blends from rigid poly(vinyl chloride) and epoxidized natural rubber

Tensile and tear failure of plasticized poly (vinyl chloride)/epoxidized natural rubber miscible blends