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Title: Microcrystalline cellulose from oil palm empty fruit bunches as filler in polylactic acid
Page Range: p.675-680
Author(s): Mohamad Haafiz M K; Azman Hassan; Reza Arjmandi; Zainoha Zakaria; Marliana M M; Syakir M I; Nurul Fazita M R
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Acid hydrolysis method was used to isolate microcrystalline cellulose (MCC) from oil palm empty fruit bunches (OPEFB) total chlorine free bleached pulp. The derived MCC was incorporated into polylactic acid (PLA) using solution casting technique in order to produce PLA/MCC composites. The chemical structure of the cellulose fragments remains unaltered as demonstrated by Fourier transform infrared spectroscopy despite acid hydrolysis. X-ray diffraction showed that the MCC has a cellulose I polymorph with 87% crystallinity index. The addition of MCC into PLA enhanced not only the thermal stability but also the Young's modulus of the PLA/MCC composites by approximately 30% at 5 phr MCC contents compared to pure PLA. However a decrease in tensile strength and elongation at break of the PLA/MCC composites were observed due to the poor dispersion of MCC in the PLA matrix. 30 Refs.

Title: A urethane block copolymer as binder for fire-resist palm-based fibreboard
Page Range: p.681-686
Author(s): Amamer Redwan; Khairiah Haji Badri; Azizah Baharum
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The mechanical properties and fire resistance of medium-density fibreboard (MDF) consisting of empty fruit bunch fibre (EFB) and palm-based pre-polyurethane (pPU) as the green binder were investigated. The EFB was in the size range of 300 to 500 (mu)m with ATH varied at 5, 10, and 15%w/w of the total mass of the resin and was added into the pPU matrix at a ratio of 65:35 of the EFB to pPU. This study discovered the significant of mixing sequence to the strength enhancement of the fibreboard. A direct proportionality was noted between the Shore D hardness and the amount of ATH with an increase up to 17% with increasing ATH content. Furthermore, this is contributed to well-disperse ATH in the pPU matrix which also increased the impact and flexural strengths. An increase in impact strength of 13, 20 and 33%, with increasing ATH loading percentage was observed. The maximum increase in flexural strength was 33%, which was associated to ATH content of 15%. On the other hand, the burning rate decreased from 6.0 to 3.2 mm(.)s-1 with increasing ATH content. 32 Refs.

Title: Ionic imprinting polymers using diallylaminomethyl-calix[4] resorcinarene host for the recognition of Pb (II) ions
Page Range: p.687-694
Author(s): Nor Nadiah Mohamad Yusof; Takaomi Kobayashi; Yasuaki Kikuchi
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
A novel ion-imprinted microspheres of copolymerised diallylaminomethyl-calix [4] resorcinarene and divinylbenzene were prepared through precipitation polymerisation. These microspheres were used for the adsorption experiments of Pb (II) ions mixture solution containing Pb (II), Ni (II) and Cu (II). The selective complexion towards Pb (II) ions was examined. The adsorption was conducted in batches by investigating the effects of pH and initial concentration of a heavy metal solution. The adsorption of Pb (II) metal ions on the adsorbents had the optimum pH rating in region of 6. For single ion system, the imprinted polymer showed that the adsorption capacity of Pb (II) metal ions was 64 mg/g, while for Cu (II and Ni (II) were 24 mg/g and 8 mg/g, respectively. Competitive extraction experiments in the presence of Cu (II) and Ni (II) ions were also carried out and high selectivity of the imprinted polymer adsorbents towards Pb (II) over Cu (II) and Ni (II) was found. In ternary mixture of heavy metal ions, the imprinted polymer showed effective adsorption to Pb (II) obeying Langmuir isotherm. The outstanding adsorption abilities for Pb (II) metal ion have exhibited good prospects for disposal application of polluted water and environmental protection. 29 Refs.

Title: Preparation of colloidal properties and water dispersible conductive polypyrrole nanocomposite of nanocrystalline cellulose
Page Range: p.695-702
Author(s): Al-Dulaimi A A; Wanrosli W D
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The development of conductive polypyrrole (PPY) processability was successfully achieved by a synthesis of colloidal form with high dispersion stability in aqueous medium. In-situ polymerisation method of pyrrole monomers (PY) assisted by aqueous suspension nanocrystalline cellulose (NCC) and the oxidising agent ammonium persulphate (APS). Facial and fast technique consisted of deposition of PY monomers on the NCC surface via electrostatic attractions between the sulphate groups in NCC surface and the amine group of the PY. Steric hindrance feature of NCC suspension significantly influences the colloid production. The nanocomposite of PPY and NCC (PPY-NCC), purified by centrifuge repeatedly and desiccated by freeze-dry technique. The observations of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), clearly shows the nanostructure modification for nanocomposite and the NCC particles after the composition. The PPY-NCC nanocomposite have very good dispersion stability in aqueous media. The variation between PPY and PPY-NCC in the crystallinity and thermal stability was studied by thermogravimetric analysis (TGA) and x-ray diffraction (XRD) respectively. 43 Refs.

Title: Synthesis of carbazole based co-polymers containing thienothiophene and benzothiadiazole units in a direct arylation scheme
Page Range: p.703-710
Author(s): Mohd Sani Sarjadi; Ahmed Iraqi
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The photovoltaic effect can be used to harvest energy from sunlight, enabling a cleaner approach to generating energy. Organic photovoltaics based on polymers are an attractive replacement of expensive, high energy consuming silicon solar cells. However, the limitations of efficiency have prevented industrial application, and polymer-based solar cells remain uncompetitive. Thus, optimisation of efficiency is required before potential application of these devices. In this work, the polymers were synthesised by direct arylation, in order to investigate its suitability for application in photovoltaic cell. Morphological, spectroscopic and charge-transport measurements are used to investigate the influence of either the dithienyl or thienothiophene moieties on the structure and photophysical properties of the copolymer rationalise the solar cell characteristics. The polymers obtained were characterised using 1H-NMR, 13C-NMR, IR, UV and thermal gravimetric analysis. The absorption spectral, thermal, electrochemical and photovoltaic properties of the random copolymers were investigated. Finally, a new series of carbazole-based dithienyl or thienothiophene polymers was successfully synthesised and characterised. 30 Refs.

Title: The role of phosphate ester as a fire retardant in the palm-based rigid polyurethane foam
Page Range: p.711-718
Author(s): Nor Rabbi'atul Adawiyah Norzali; Khairiah Haji Badri
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Palm-based polyurethane containing phosphate ester (PE) as fire retardant has been developed. This study was conducted to investigate the effect of PE inclusion into palm-based polyurethane (PU) system onto the mechanical and burning property of the PU. The PE was synthesised via ring-opening hydrolysis between phosphoric acid (H3PO4) and epoxy. The synthesis was conducted at 60-70 deg C with varying concentration of H3PO4 at 2.5, 5.0 and 7.5 wt.%. It was then added into the PU system at 0, 5, 10 and 15 wt.%. Density of the PU foam was in the range of 45-50 kg(.)m-3. PE increased the compression strength and modulus of the PU. The highest compression stress (1441 kPa) and modulus (7733 kPa) were discovered with the addition of 10 wt.% PE. Burning properties showed that the addition of PE has decreased the burning rate of the PU foam. PU with PE synthesised from 5.0 wt.% H3PO4 showed excellent burning properties with the lowest burning rate (0.047 cm(.)s-1) compared to control PU which was at 0.119 cm(.)s-1. 23 Refs.

Title: Preparation of cellulose nanocrystals bio-polymer from agro-industrial wastes: separation and characterization
Page Range: p.719-728
Author(s): Mazlita Y; Lee H V; Hamid S B A
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Lignocellulosic biomass from oil palm agro-industrial waste is highly potential to be valorised into cellulose polymer in nanoscale, which is useful for various applications. The present study discussed the synthesis of cellulose nanocrystal (CNC) from oil palm trunk (OPT) biomass via chemical-sonication process. The effect of pretreated alkali-bleached OPT and H2SO4 acid hydrolysed (40% and 60% w/w) cellulose were investigated by utilising X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). Biomass crystallinity, thermal stability and chemical functional group suggested that the pretreatment process has successfully isolated cellulose from OPT, which indicated the removal of lignin, hemicellulose and impurities from the palm fibres. Furthermore, SEM and TEM images revealed that CNC40 and CNC60 were observed in rod-shaped structure with the dimension of 100.00 nm (L) x 27.50 nm (d) and 95.00nm (L) x 25.00nm (d), respectively, and corresponded to the aspect ratio of 3.63 and 3.80, respectively. In the presence of sonication condition, the study suggested that both 40 and 60%w/w of H2SO4 rendered active effect for acid depolymerisation of cellulose at 45 deg C and 15 min of time. Thus, this can concluded that milder acid (40%w/w) was able to produce cellulose in nanosizes under mild operating condition with the assistant of sonication effect. 40 Refs.

Title: Exploring the potentials of nanocellulose whiskers derived from oil palm empty fruit bunch on the development of polylactid acid based green nanocomposites
Page Range: p.729-734
Author(s): Mohamad Haafiz M K; Azman Hassan; Reza Arjmandi; Marliana M M; Nurul Fazita M R
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
In this study, nanocellulose whiskers (NCW) from oil palm empty fruit bunches (OPEFB) were used as reinforcement phase in polylactid acid (PLA). Two techniques were employed to isolate the NCW from OPEFB microcrystalline cellulose (OPEFB-MCC); chemical swelling with DMAc containing 0.5% LiCl to generate the NCW and acid hydrolysis with 64% H2SO4 to generate the NCW-S. The atomic force microscopy showed that the isolated NCW and NCW-S are in nanoscale dimension and displayed an individual rod-like structure. The fillers were then incorporated in PLA matrix at different loadings (1, 3, and 5 parts per hundred resin (phr)) to produce P-NCW and P-NCW-S nanocomposites via solution casting technique. The mechanical properties of the developed nanocomposites were investigated by means of tensile test. The results showed that the tensile strength of nanocomposites increased by 84% and 64% for the NCW and NCW-S reinforced PLA nanocomposites, respectively. The Young's modulus of nanocomposites increased linearly with the fillers loading. Expectedly, the percent elongation at break was impacted negatively as it decreased with fillers loading. The thermogravimetric analysis showed that the decomposition temperatures (T10, T50 and Tmax) of P-NCW were higher than neat PLA. In the case of P-NCW-S however, the thermal stability decreased with the additional of NCW-S. 25 Refs.

Title: Effects of recycling cycle on used thermoplastic polymer and thermoplastic elastomer polymer
Page Range: p.735-740
Author(s): Yu Lih Jiun; Cher Tien Tze; Usaid Moosa; Tawawneh M A
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Due to several environmental problems arising through the disposal of polymers, recycling has been growing rapidly as one of the best approaches to minimise environment pollution issue. Apart from the positive impacts towards environmental sustainability, recycling polymer is also benefiting in terms of manufacturing cost reduction, energy conservation and material resource conservation. The aim of this study was to investigate how recycling cycle affects the physical properties and mechanical properties for both used thermoplastic polymer and thermoplastic elastomer polymer. Samples were prepared by melting used polymers via melt blending technique. Results showed that tensile strength and density were decreased for thermoplastic polymer and the changes in visual are significant when the number of recycling cycle was increased. Tensile strength, yield strength and Young Modulus of thermoplastic elastomer are independent from number of recycling cycles. Presence of antioxidant fillers in thermoplastic elastomer enhanced the tensile strength (28.23%) and Young Modulus (29.16%) when the polymers were exposed to ultraviolet light. 25 Refs.

Title: Biodegradability and thermal properties of hybrid montmorillonite/microcrystalline cellulose filled polylactic acid composites: effect of filler ratio
Page Range: p.741-746
Author(s): Reza Arjmandi; Azman Hassan; Mohamad Haafiz M K; Zainoha Zakaria
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The objective of this study is to investigate the effects of partial replacement of montmorillonite (MMT) with microcrystalline cellulose (MCC) on the biodegradability and thermal properties of hybrid MMT/MCC filled polylactic acid (PLA) composites prepared using solution casting technique. Based on our previous study, the optimum MMT content based on having the highest tensile strength in PLA/MMT nanocomposites is 5 phr (parts per hundred parts of polymer). Therefore, the PLA/MMT/MCC hybrid composites were prepared at a total filler content of 5 phr. The biodegradability and thermal properties of PLA hybrid composites were investigated using soil burial test and thermogravimetric analysis, respectively. The biodegradability of PLA/MMT/MCC hybrid composites (1 phr MMT and 4 phr MCC) at 8th week significantly increased by approximately 228% and 367% compared to the optimum formulation of PLA/MMT nanocomposite and neat PLA, respectively. In addition, Fourier transform infrared spectroscopy (FTIR) revealed the formation of hydrogen bonding between the fillers and PLA matrix. The thermal stability of hybrid composites improved from 358.3 to 362.2 deg C by incorporation of hybrid MMT/MCC (1 phr MMT and 4 phr MCC) into PLA matrix, as demonstrated by maximum decomposition temperature. 26 Refs.

Title: TiO2-SiO2-reinforced methylated grafted natural rubber (MG49-TiO2-SiO2) polymer nanocomposites: preparation, optimization and characterization
Page Range: p.747-754
Author(s): Oon Lee Kang; Azizan Ahmad; Nur Hasyareeda Hassan; Usman Ali Rana; Mohd Sukor Suait; Migliaresi C
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
TiO2-SiO2 (30:70) and (70:30) sol particles were first prepared through ClHNO2-EtOH catalysis; and then incorporated into methylated grafted natural rubber (MG49) polymer host. Resultant MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites were characterised through XRD and FTIR analyses. Both MG49-TiO2SiO2 (30:70) and (70:30) polymer nanocomposites had exhibited extensive reduction in semicrystalline phase; but no significant change in structural properties. Low crystalline MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites were further characterised through SEM, TGA and DRA analyses. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had exhibited different dispersion state on fracture surface. Both MG49-TiO2-SiO2 (30:70) and (70:30) polymer nanocomposites had demonstrated significant improvement in thermal properties, and also some improvement in rheological properties. 13 Refs.

Title: Mechanical, thermal and instrumented impact properties of bamboo fabric-reinforced polypropylene composites
Page Range: p.755-766
Author(s): Mahmud Zuhudi N Z; Jayaraman K; Lin R J T
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Many automotive companies are experimenting with natural fibres as a substitute for glass fibres in polymer composites, especially polypropylene (PP) based composites. PP composites reinforced by plain woven bamboo fabric have recently been widely investigated. Bamboo in woven fabric form embedded in the polymer results in easier material handling during production and reduction in the manufacturing cost of the composites. In the current study, the performance of twill-weave bamboo fabric-reinforced PP composites, which were fabricated using a compression moulding method, was evaluated. The mechanical, thermal and impact performances of the bamboo fabric-reinforced PP (BPP) composites were evaluated in comparison to those of PP, at various bamboo contents and stacking sequences. The incorporation of bamboo fabric resulted in the improvement of tensile strength, tensile modulus, flexural strength, flexural modulus and Charpy impact strength of PP by 238%, 110%, 180%, 170% and 160%, respectively. The integration of bamboo fabric slightly increased the melting temperature and the degree of crystallinity of the composites. A 40% decrease in the heat of fusion of the composites was observed compared to that of PP. Impact tests were also conducted using an instrumented drop weight impact test system. The perforation impact energy, peak load and energy absorbed of the composites increased when the bamboo content was increased. The perforation impact energy was at 55 J for the BPP50% composite, compared to that of neat PP at 20 J. The crack damage in the composites was also reduced with the presence of fabric reinforcement. These results indicate that bamboo fabric is truly a new contender for developing excellent and economical light-weight composites as interior components in automobiles. 35 Refs.

Title: Mechanical properties of bio-composite natural rubber/high density polyethylene/ mengkuang fiber (NR/HDPE/MK)
Page Range: p.767-774
Author(s): Mohd Razi Mat Piah; Azizah Baharum; Ibrahim Abdullah
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The use of mengkuang fibre (MK) as a filler in NR/HDPE/MK bio-composite was investigated. The suitability of MK as reinforcing filler was studied in terms of the mechanical properties and phase morphology formed. Melt-blending was performed using an internal mixer (Haake Rheomix 600). The processing parameters identified were 135 deg C temperature, 45 rpm rotor speed and 12 min processing time. The optimum MK loading in 40/60 of NR/HDPE blend was obtained at 20 wt.% with the tensile strength, tensile modulus, and impact strength of 12.4 MPa, 377 MPa and 17.2 kJ/m2, respectively. These results showed an enhancement in tensile strength of 10.7% compared to the unfilled NR/HDPE blend. The maximum impact strength obtained at 5% fibre loading was 23.5 kJ/m2, which was 7.8% higher compared to unfilled NR/HDPE blend. The FESEM micrographs showed good adhesion between MK fibre and matrix. These mechanical properties enhancements proved the suitability of mengkuang fibre as potential reinforcing filler in NR/HDPE blend. 24 Refs.

Title: Properties of epoxidized natural rubber tread compound: the hybrid reinforcing effect of silica and silane system
Page Range: p.775-782
Author(s): Siti Salina Sarkawi; Ahmad Kifli Che Aziz; Rohaidah Abdul Rahim; Rassimi Abdul Ghani; Ahmad Nazir Kamaruddin
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Modification of natural rubber via epoxidation process increases its compatibility with highly polar filler like silica. In this work, epoxidised natural rubber (ENR) reinforced with silica compound is evaluated for truck tyre tread compound. The rheological, physical and dynamic properties as well as the bound rubber content of ENR-silica tread compound are discussed. The results show that ENR-silica compound has high chemically bound rubber indicating the good interaction and bonding between rubber and silica. In addition, the dynamic test shows the ENR-silica vulcanisate exhibit higher Tan delta at 0 deg C and lower tan delta at 60 deg C as compared to conventional natural rubber-carbon black vulcanisate, which gives indication of higher wet grip and lower rolling resistance of the ENR vulcanisate. The use of ENR reinforced with silica filler in tread compound is a unique combination that offers renewable material for greener tyre application. 20 Refs.

Title: Effect of micro- and nano- size of cellulose particles extracted from rice husk on the properties of hydrogels
Page Range: p.783-788
Author(s): Wan Hafizi Wan Ishak; Ooi Shok Yin; Ishak Ahmad
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The effects of different size of cellulose particles extracted from rice husk on the properties of gelatin/cellulose hydrogels were studied. Micro size cellulose was extracted by alkali and bleaching treatments followed by acid hydrolysis to obtain cellulose nanocrystal (CNC). Both cellulose (micro) and CNC (nano) were used in hydrogels formulation with gelatin (in ratio 25% cellulose dispersion to 75% gelatin). Gelatin was then subjected to chemical cross-linking using glutaraldehyde as crosslinking agent with CNC entrapped in gelatin to produce hydrogels. SEM observation revealed that swollen micro cellulose has irregular and bigger pores compared to cellulose nanocrystal (CNC) hydrogel which has homogeneous and smaller pores arrangement thus affecting their swelling degree. The cellulose fibres exhibit enhanced thermal stability but contrary with the cellulose nanocrystals which showed lower thermal stability. 22 Refs.

Title: Efficacy of fibre aspect ratio and prepolymerised polyurethane as binder in enhancing strength of palm-based fibreboard
Page Range: p.789-794
Author(s): Azlin Mohmad Azman; Azizah Baharum; Khairiah Haji Badri
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Palm-based medium-density fibreboard (palm-based MDF) comprised of polyurethane prepolymer (pPU) and palm oil empty fruit bunch fibre (EFB) was prepared. The pPU was a reacting mixture in acetone consisted of palm kernel oil-based monoester polyol (PKO-p) and 4,4-diphenylmethane diisocyanate (MDI) with polyethylene glycol (Mw of 200 kDa, PEG200) as the plasticiser. EFB with size ranging from 250 (mu)m to 500 (mu)m (MDF S1), 500 (mu)m to 1000 (mu)m (MDF S2) and 1000 (mu)m to 2000 (mu)m (MDF S3) was investigated. The flexural strength and modulus increased with decreasing fibre size with optimum strength and modulus at 46.7 MPa and 1923 MPa respectively. Higher glass transition temperature (Tg at 77 deg C) was observed in MDF S1 compared to MDF S3 (Tg at 67 deg C). FTIR spectrum indicated possible formation of urethane linkage between the reactive NCO active groups in pPU with OH group from cellulose constituent in EFB fibre. 14 Refs.

Title: Effect of halloysite nanoclay concentration and addition of glycerol on mechanical properties of bionanocomposite films
Page Range: p.795-802
Author(s): Nazratul Putri Risyon; Siti Hajar Othman; Roseliza Kadir Basha; Talib R A
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Conventional plastic made from petrochemical based polymer which is non-degradable is not environmentally friendly. Thus, there is a need to develop bionanocomposite films to replace the non-degradable plastic. Bionanocomposite films were produced by the casting method using polylactic acid (PLA) biopolymer with the incorporation of nanoclay, particularly halloysite. The effect of the halloysite nanoclay concentration (0, 2, 4, 6 and 8 wt.%) as well as the addition of a plasticiser, particularly glycerol, on the mechanical properties (tensile stress, elongation at break and tensile strength) of bionanocomposite films was investigated. It was found that without the addition of glycerol, 2 wt.% concentration of halloysite nanoclay film resulted in the maximum tensile strength and elongation at break due to the interaction of the PLA and the nanoclay which is known for interfacial adhesion. The interaction was confirmed by FTIR spectrum. When more than 2 wt.% of nanoclay clay was added, both the tensile strength and the elongation at break reduced due to the agglomeration of the nanoclay. However, when glycerol was added, the film without the addition of halloysite nanoclay exhibited the maximum tensile strength and the film with 8 wt.% halloysite nanoclay exhibited the maximum elongation at break. The addition of glycerol lowered the mechanical properties of the films because the intercalation of the glycerol into the clays prevented the entry of PLA into the interlamellar of the nanoclay. 30 Refs.

Title: Polyethersulfone nanofiltration membrane incorporated with silicon dioxide prepared by phase inversion method for xylitol purification
Page Range: p.803-808
Author(s): Faneer K A; Rosiah Rohani; Wahab Mohammad A
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
Xylitol purity is essential for a high value product obtained from biomass fermentation. Common biomass fermentation from sugar cane bagasse, corncobs or rice husk source in the presence of yeast produces xylitol mixture (containing xylose, arabinose), thus, various methods have been used for the purification such as crystallisation and adsorption. However, membrane technique is of interest due to the operational simplicity and flexibility, relatively high selectivity and permeability for the transport of specific components. Nanofiltration (NF) membrane is targeted for the membrane application based on the ranges of molecular weight of the mixture components that fall in NF (between 200 to 2000 g/mol). In this paper, a new and efficient NF membrane used for purifying xylitol was synthesised from polyethersulphone (PES) and PES incorporated with silicon dioxide (SiO2) nanoparticles (NP) of 5 wt.% via phase inversion technique. These membranes have been characterised for their chemical, physical and morphological properties and their performances have been evaluated in the dead end filtration to obtain the pure water flux and filtration performance using xylitol mixture. EDX showed the presence of SiO2 NP on the membrane for PES/SiO2 membrane but none in PES membrane. The membrane permeation properties improved also when SiO2 has been incorporated to the PES membrane. The hydrophilicity of the PES/SiO2 membrane measured by contact angle improved from 79.7 plus/minus 0.65o to 59.1 plus/minus 0.15o for PES/SiO2 and PES membranes, respectively. The water flux has enhanced for PES/SiO2 membrane from 24.56 to 59.14 L/m2(.)h measured at 4 bar. Therefore, in terms of flux and contact angle, the synthesised membrane of PES/ SiO2 was found to be more effective compared to pure PES membrane. 26 Refs.

Title: Reused carbon fibre as reinforcing filler in palm-based polyurethane composites
Page Range: p.809-814
Author(s): Mariana Mohd Zaini; Nor Rabbiatul Adawiyah Norzali; Khairiah Haji Badri
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The loading effect of recycled carbon fibre at 5, 10, 15 and 20 wt.% on the mechanical strength of the palm-based polyurethane (PU-rCF) was investigated. The recycled carbon fibre (rCF) from glycolysis of the carbon fibre epoxy mat (CFRP) was obtained. The glycolysis was conducted at 180-190 deg C under atmospheric pressure and catalysed by 1.9 wt.% NaOH in 80% aqueous medium. The rCF was analysed by FTIR spectroscopy analysis and SEM observation. Clean fibre without residual traces was obtained. The rCF was then incorporated into palm-based polyurethane to form composite panel (PU-rCF).The addition of rCF improved the mechanical strength of the composite. The impact strength increased more than 3 folds from 0.6 kJ/m2 to 3.8 kJ/m2 while the flexural strength increased from 43 MPa to 61 MPa. The shore D hardness index was at the highest (72) with maximum rCF loading of 20 wt.%. As expected, the FTIR spectrum of the PU-rCF indicated the absence of chemical interaction between PU and the rCF. The strong physical interaction between the rCF fibre strands has decreased the brittleness of the PU and increased the mechanical strength of the composites. 21 Refs.

Title: Homogeneous and heterogeneous solid state self-healing system
Page Range: p.815-824
Author(s): Noor Nabilah Muhamad; Mohd Suzeren Md Jamil
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Journal: Polymers and Polymer Composites
Issue Year: ppc
Volume: 24
Issue No: No.9

Abstract
The solid state self-healing system was obtained by employing a thermosetting epoxy resin, into which a thermoplastic is dissolved. The aim of this study is to investigate the homogeneous and heterogeneous solid state self-healing system by using thermoplastics comprised of poly(bisphenol-A-co-epichlorohydrin) (PDGEBA), polyvinyl chloride (PVC), polyvinyl alcohol (PVA), polyethylene (PE) and polypropylene (PP) as healing agents. PDGEBA produced homogenous resin blend which undergone random molecule diffusion healing process. A heterogeneous resin blend composed of 8 wt.% PVC, PVA PE, and PP, yielding a "bricks and mortar" morphology wherein the epoxy phase exists as a matrix (mortar) interpenetrated with a percolating thermoplastic (bricks). The healing process in heterogeneous resin blend is attributed to volumetric thermal expansion of healing agent above its melting point in excess of epoxy brick expansion. Healing was achieved by heating the fractured resins to a specific temperature; above their glass transition temperature (Tg) which obtained from dynamic mechanical analysis (DMA) in order for diffusion process and thermal expansion to occur. The thermal properties and bonding formed in the epoxy resins were characterised by means of Fourier Transform Infrared Spectroscopy (FTIR) and dynamic mechanical thermal analysis (DMTA). Izod impact test and compact tension test were conducted to demonstrate details self-healing capability of different specimens. Results of Izod impact test are in agreement with the result of compact tension test. Under compact tension test, the healable resin with PDGEBA has the highest healing efficiency of 60% followed by PVC, PP, PE, and PVA with 39%, 37%, 28% and 21% of average percentage healing efficiencies in three healing cycle respectively. Morphological studies using optical microscope verified the fracture-healing process and morphological properties of the resins. 25 Refs.

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