Bionanocomposite hybrid polyurethane (BHPU) foams that exploit the tribute of natural fibers and nanoclay in green PU foam can lead to the new imminent in engaging the nanoclay and natural fibers. PU filled empty fruit bunch (EFB), PU filled silane treated EFB (sEFB) and PU filled organo montmorillonite (oMMT) have been prepared as control, and the hybridization has carried out for 1/4, 1/2 and 3/4 ratios between EFB/oMMT and sEFB/oMMT. The hybridization of these natural fibers and oMMT permit to retain the strength without compromise the stiffness of BHPU. The hybridization also improves the barrier and thermal properties of these BHPU. Microscopic studies shows that the hybridization of these natural fibers and nanoclay provide initial evidence of the possibilities on the insertion of nanoclay into the natural fibers, thus open the opportunities to exploit this behavior to another hybrid system. (C) 2012 Elsevier Ltd. All rights reserved.

In this study, the effect of adding cellulose nanocrystal (CNC) on the conductivity of biopolymer electrolyte (BPE) based on chitosan-methylcellulose-BMIMTFSI has been studied. The samples were prepared via solution casting technique. The film was characterized by impedance spectroscopy HIOKI 3531-01 LCR Hi-Tester to measure its ionic conductivity at room temperatures over a wide range of frequency between 50Hz-5MHz. Sample with 15 wt% of CNC shows the highest conductivity of 4.82 x 10(-6) Scm(-1) at room temperature. Dielectric and modulus studies were carried out to further understands the conductivity behavior of the samples. The increase in conductivity is mainly due to the increase in number of charge carriers.

Polyurethane (PU) adhesives were prepared from the reaction of polycaprolactone (PCL) polyols based on palm kernel oil based polyesteramide (PPKO) with an aromatic and cycloaliphatic diisocyanate. Four different formulations of PU adhesives were prepared by varying the NCO : OH ratio, in order to investigate the effects of NCO : OH ratios on adhesion strength. The adhesive strength of metal-metal bonding both in dry and hydrothermal ageing-was determined by single lap shear joint testing. The resistance to hydrolysis of the PU adhesives was determined by performing water absorption tests. The water absorption test samples suggested that the durability of the adhesives correlated to lower water absorption due to higher NCO content. The correlation between the crosslinking of the PU network and adhesive strength was also studied by performing swelling tests. The higher NCO content showed that, the higher crosslink density of PUs led to higher cohesion and adhesion strengths. PU1.7 showed optimal properties in terms of durability and resistance to hydrolysis, whereas PU2.0 revealed deterioration in durability and resistance to hydrolysis due to the presence of greater micro-voids content in the PU2.0 matrix. (C) 2014 Wiley Periodicals, Inc.

Shape memory polymers (SMP) are smart materials with the ability of changing shape when subjected to external stimuli. In this work, the shape memory polyurethane (SMPU) has been synthesized via two step bulk polymerization method by replacing up to 40% molar ratio of petroleum-based polyol using palm oil-based polyols (POP). This effort was done with the purpose of reducing the usage of petroleum-based polyol due to environmental awareness. The main objective is to investigate the effects of different polyol/isocyanate/1,4-butanediol molar ratio in relation to soft-hard segment content towards the mechanical and shape memory properties of the resulting SMPU. The mechanical properties were improved with POP addition and optimum performance of tensile properties were obtained within 35 to 40% of hard segment content. Tensile strength increased with increasing POP content but after 40% of hard segment content, the properties decreased. On the other hand, the modulus significantly reduced with an increase of hard segment content. Crystallinity also decreased with decreasing of polycaprolactone diol (PCL) content as more POP content was added. Shape memory properties of PU 165 is better than PU 154 in terms of the ability to return to its original shape since all of PU 165 samples showed 100% recovery. In general, the addition of palm oil-based polyol showed improvement in mechanical and shape memory properties as compared to pristine SMPU.

Surface treatment of aluminium alloy plays a significant role in improving the strength of the adhesive bond. In this study, an aluminium alloy 2024-T3 was treated by two different methods of surface treatments i.e. by alkaline etching and warm water treatment followed by silanization method in order to enhance the adhesive bonding. Three different formulations of polyurethane adhesive by varying the NCO:OH ratios which were prepared from polyol polycaprolactone (PCL) based on palm kernel oil polyesteramide (PPKO) with a blend of aromatic and cycloaliphatic diisocyanate. Surface morphology, surface chemical analysis, wettability and surface roughness of the treated samples were characterised using field emission scanning electron microscopy and energy dispersive X-ray analysis (FESEM/EDX), X-Ray Photoelectron Spectroscopy (XPS), contact angle goniometry and surface profilometry, respectively. The influences of surface treatment techniques and conditions on durability of the joint strength and interfacial properties were explored by performing the single lap shear test and wedge test. The effects of NCO:OH ratios on PU adhesive strength were also investigated. Durability of PU adhesive bonding is found to display an interesting dependence on the surface treatments. (C) 2014 Elsevier Ltd. All rights reserved.

The green synthesis of silver nanoparticles with the small size and high stability paved the way to improve and protect the environment by decreasing the use of toxic chemicals and eliminating biological risks in biomedical applications. Plant mediated synthesis of silver nanoparticles is gaining more importance owing its simplicity, rapid rate of synthesis of nanoparticles and eco-friendliness. In this study, focus on biosynthesis of silver nanoparticles using Polygonum hydropiper extract and its catalytic degradation of hazardous dye, methylene blue has been highlighted. The rapid reduction of silver (Ag) ions was monitored using UV-Visible spectrophotometer and showed formation of silver nanoparticles within less than one hour with maximum absorption of silver nanoparticles at 430 nm. The major functional groups present in the synthesis responsible for the formation of silver nanoparticles. It was identified by using Fourier Transform Infrared spectrophotometer (FTIR). Field Electron Scanning Microscope (FESEM) was used to characterise the nanoparticles synthesized using P.hydropiper. The morphology of silver nanoparticles was predominantly spherical and aggregated into irregular structure with average diameter of 60 nm. In addition, this report emphasizes the effect of the silver nanoparticles on the degradation rate of hazardous dyes by sodium borohydride (NaBH4). The efficiency of silver nanoparticles as a promising candidate for the catalysis of organic dyes by NaBH4 through the electron transfer process is established in the present study. (C) 2016 Published by Elsevier B.V.

Shape memory polyurethanes (SMPU) are one of the advanced materials that have potential applications in the field of biomedical particularly vascular stent. This paper studies the effect of incorporating palm oil polyol (POP) up to 40% molar ratio in place of petroleum-based polyol in the preparation of SMPU due to environmental concern. Polycaprolactone diol was utilized as the soft segment while 4,4-diphenylmethane diisocyanate and 1,4-butanediol as the hard segments. The SMPU was prepared using two-step prepolymer method, and the fabricated samples were characterized to study the effect of POP on the thermal properties, tensile, and shape memory behavior of polyurethane. The results obtained have shown that SMPU with incorporation of POP showed good shape fixity (100%) and elongation at break (245%) up to 20% molar ratio of POP. The presence of dangling chains of fatty acid in POP was believed to enhance the flexibility of SMPU molecular chains by acting as a plasticizer. On the other hand, the shape recovery of SMPU remains high even at 40% molar ratio of POP, and the thermal stability of SMPU increased with the addition of POP. It is proposed that the synthesized POP-based SMPU is a suitable candidate for cardiovascular stent as they possessed desired thermal, mechanical, and shape memory properties.

Montmorillonite K10 (MMT K10), the major clay mineral commercially available can be treated to improve its properties and thus can be utilized for a broad range of organic reaction including esterification of fatty acids for biodiesel production. However, the use of unmodified MMT K10 in esterification of fatty acids showed that the acid conversion was less than 60 %. The aim of this study is to utilize available material i.e. MMT K10 modified with Cu2+, Al3+ and Fe3+ at various concentrations as catalyst for the esterification of acetic acid and stearic acid. The x-ray diffraction and elemental analysis of the materials were successfully characterized. After characterization, the materials were evaluated for the esterification of acetic acid and stearic acid with methanol. Prepared catalysts were able to give the highest acid conversion of up to 75% relative to the unmodified MMT K10 revealing the potential of M-MMT K10 as catalyst for esterification in biodiesel production.

This paper described the effect of empty fruit bunch (EFB) loading in the medium density rigid foam, which was prepared from the palm kernel oil based polyol. The grounded 300 mu m EFB fiber was used as filler and its composition were varied from 3, 6, 9 and 12 weight percent. EFB filled PU shown good dimensional stability at 70 degrees C and -15 degrees C due expending and shrinking percentage are less than 0.8% and 0.4% respectively. The mechanical properties were increased linearly with the EFB loading until it reached an optimum percentage of the EFB. SEM images shows the usage of big size cylindrical particle suggested that the fiber pull out will responsible for the synergistic effect of flexibility and strength of the biofoam produced.

A series of nanoclay reinforced thermoplastic polyurethane with shape memory effect have been successfully synthesized via two-step polymerization process. The polyurethanes are composed of polycaprolactonediol, palm oil polyol, 4,4'-diphenylmethane diisocyanate and 1,4-butanediol. Nanoclay was added in order to improve the overall properties of the pristine polyurethane. Besides, the addition of palm oil polyol is believed to enhance the crosslinking process and further improve the properties. X-ray diffraction result showed that there is a decrease in crystallinity of polyurethane nanocomposites as clay is added. Good shape memory and mechanical properties of resulting polyurethane nanocomposites were obtained in this work.

Zinc oxide plays an important role in current industry due to its special characteristics such as anti-corrosion, anti-bacteria, has low electrons conductivity and excellent heat resistance. Therefore, the objective of this study is to synthesize zinc oxide nanostructures with the most practical ways by using sol-gel method and characterize the nanostructures. Sol-gel method is the simplest method and has the ability to control the particle size and morphology through systematic monitoring of reaction parameters. ZnO nanoparticles were synthesized via sol gel method using Zinc acetate dehydrate (Zn(CH3COO)(2)center dot 2H(2)O) as a precursor and ethanol (CH2COOH) was used as solvent, Sodium hydroxide ( NaOH) and distilled water were used as medium. ZnO nanoparticles were characterized by using XRD, EDX, FESEM, and nano-particles analyser. Result of EDX characterization shows that the ZnO nanoparticles has good purity with (Zinc content of- 55.38% and; Oxygen content of- 44.62%). XRD result spectrum displays mainly oxygen and zinc peaks, which indicate the crystallinity in nature as exhibited. FESEM micrographs shows that synthesized ZnO have a rod-like structure. The obtained ZnO nanoparticles are homogenous and consistent in size which corresponds to the XRD result that exhibit good crystallinity. ZnO nanoparticles were successfully synthesized by sol-gel method in nanosize range within 81.28nm to 84.98nm. (C) 2016 The Authors. Published by Elsevier B.V.

This study is conducted to evaluate the tensile properties of silicon carbide nanoparticles (SiCNP) and multiwalled carbon nanotubes (MWCNTs) filled toughened epoxy composites as a function of filler loading. The nanocomposites with different weight percentage of SiCNP and MWCNTs loading were fabricated by mechanical blending operation assisted with an ultrasonic cavitation technique. The loadings utilized were 0, 2, 4, and 6% of total composites weight. The result shows that the optimum filler loading of both systems were obtainable at 4% of SiCNP and MWCNTs of loadings. Composite with SiCNP filler achieved the highest value of tensile strength and Young's modulus at about 11% and 4%, respectively as compared to unfilled system. The enhancement pattern in MWCNTs nanocomposite systems were not significant as compared than SiCNP composite. The tensile strength and Young's modulus of MWCNTs composite were increased at only about 7% and 2%, respectively compared than unfilled system. The strain at break attribute for both filler system had shown reduction pattern at higher loading started from 2% loading and onwards. The variation in tensile properties were further supported by the tensile fracture morphologies and clearly shown that the filler-matrix plated an important role in affecting the tensile behavior of nanocomposite produced. (C) 2016 Published by Elsevier B.V.

The main objective of this study was to investigate the effect of different types and molecular weight (MW) of polyol on the shape memory properties of palm kernel oil-based shape memory polyurethane (SMPU) prepared by two step bulk polymerization procedure. Poly(ethylene glycol) (PEG) and poly(epsilon-caprolactone) (PCL) with MW 2000 and MW 4000 were used as the main material for soft segment. The addition of palm kernel oil polyol (PKO-p) in the SMPU system is due to the concern of the renewable resources. Shape fixity and shape recovery properties were investigated using bending test to evaluate the shape memory effect. The results indicate that the shape fixity of SMPU depends primarily on the types of polyol whereas MW had a slight effect towards the shape fixity. SMPU synthesized from PEG with MW 2000 performed a good shape fixity, about 96% compared to that of PCL with MW 2000, about 29%. In the case of PCL - based SMPU, the increase of shape fixity is proportional to the increase of MW. All samples, except the one based on PEG4000, exhibited excellent shape recovery (100%). (C) 2019 Elsevier Ltd. All rights reserved.