Publications in 2015


Thermal and mechanical properties of poly(butylene succinate) films reinforced with silica
Sangviroon N., Potiyaraj P.

Abstract
In recent year, bioplastics have become more popular resulting from the growing concerns on environmental issues and the rising fossil fuel price. However, their applications were limited by its mechanical and thermal properties. The aim of this research is thus to improve mechanical and thermal properties of PBS bioplastic films by reinforcing with silica. Due to the poor interfacial interaction between the PBS matrix and silica, glycidyl methacrylate grafted poly(butylene succinate) (PBS-g-GMA) was used as a compatibilizer in order to improve the interaction between bioplastic films and filler. PBS-g-GMA was prepared in a twin-screw extruder and analyzed by the FTIR spectrometer. PBS and silica were then mixed in a twin-screw extruder and processed into films by a chillroll cast extruder. The effects of silica loading on thermal and mechanical properties of the prepared bioplastic films were investigated. It was found that the mechanical properties of PBS/silica composite films were improved when 1%wt of silica was added. However, the mechanical properties decreased with increasing silica loading due to the agglomeration of silica particles. The results also show that the silica/PBS films with PBS-g-GMA possessed improved mechanical properties over the films without the compatibilizer. © Owned by the authors, published by EDP Sciences, 2015.
keywords
Acrylic monomers; Butenes; Film preparation; Fossil fuels; Mechanical properties; Reinforced plastics; Reinforcement; Silica; Thermodynamic properties; Environmental issues; FT-IR-spectrometers; Glycidyl methacrylate; Interfacial interaction; Mechanical and thermal properties; Poly (butylene succinate); Thermal and mechanical properties; Twin screw extruders; Composite films

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Alginate/carboxymethyl cellulose hydrogel films in relation to crosslinking with glutaraldehyde and copper sulfate
Sritweesinsub W., Charuchinda S.

Abstract
Alginate/carboxymethyl cellulose (CMC) hydrogel films using glutaraldehyde (GA) and/or copper sulfate (Cu2+) as crosslinking agents were prepared. The ratios of alginate to CMC were varied at 0:10, 2:8, 4:6, 6:4, 8:2 and 10:0 in the presence of GA at 0, 2, 5% and/or copper sulfate of 0 and 0.02 mol. The Fourier Transform Infrared Spectroscopy (FTIR) spectra of hydrogels indicated the intermolecular interaction between CMC with GA and alginate with Cu2+. Using a couple of GA and Cu2+, as crosslinking agents, the hydrogels exhibited better swelling time than that of a crosslinking agent alone. The percentages of solid remains were increased by increasing both of alginate ratio and Cu2+ content. © Owned by the authors, published by EDP Sciences, 2015.
keywords
Alginate; Cellulose; Cellulose films; Copper; Fourier transform infrared spectroscopy; Sulfur compounds; Cellulose hydrogels; Copper sulfate; Cross linking agents; Glutaraldehydes; Hydrogel films; Intermolecular interactions; Swelling time; Hydrogels; Carboxymethyl Cellulose; Copper Sulfate; Cross Linking; Fourier Analysis

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Patterned Poly(acrylic acid) Brushes Containing Gold Nanoparticles for Peptide Detection by Surface-Assisted Laser Desorption/Ionization Mass Spectrometry
Sangsuwan A., Narupai B., Sae-Ung P., Rodtamai S., Rodthongkum N., Hoven V.P.

Abstract
Patterned poly(acrylic acid) (PAA) brushes was successfully generated via photolithography and surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization of acrylic acid as verified by water contact angle measurements and FT-IR analysis. The carboxyl groups of PAA brushes can act as reducing moieties for in situ synthesis of gold nanoparticles (AuNPs), without the use of additional reducing agent. The formation of AuNPs was confirmed by transmission electron microscopy and X-ray photoelectron spectroscopy. The glass surface-modified by PAA brushes and immobilized with AuNPs (AuNPs-PAA) can be used as a substrate for SALDI-MS analysis, which is capable of detecting both small peptides having m/z ≥ 600 (glutathione) and large peptides having m/z ≤ 1000 (bradykinin, ICNKQDCPILE) without the interference from matrix signal suggesting that AuNPs were stably trapped within the PAA brushes and the carboxyl groups of PAA can serve as internal proton source. By employing AuNPs as the capture probe, the AuNPs-PAA substrate can selectively identify thiol-containing peptides from the peptide mixtures with LOD as low as 0.1 and 0.05 nM for glutathione and ICNKQDCPILE, respectively. An ability to selectively detect ICNKQDCPILE in a diluted human serum is also demonstrated. The patterned format together with its high sensitivity and selectivity render this newly developed substrate a potential platform for high-throughput analysis of other biomarkers, especially those with low molecular weight in complex biological samples. © 2015 American Chemical Society.
keywords
Carboxylic acids; Desorption; Fiber optic sensors; Free radical polymerization; Gold; High resolution transmission electron microscopy; Mass spectrometry; Metal nanoparticles; Nanoparticles; Organic acids; Peptides; Photolithography; Synthesis (chemical); Transmission electron microscopy; Biological samples; Gold Nanoparticles; High-throughput analysis; Low molecular weight; Poly(acrylic acid ); Reversible addition-fragmentation chain transfer polymerization; Surface-assisted laser desorption/ionization; Water contact angle measurement; X ray photoelectron spectroscopy; acrylic acid; acrylic acid derivative; glass; gold; nanoparticle; peptide; polymer; chemistry; human; mass spectrometry; Acrylates; Glass; Gold; Humans; Nanoparticles; Peptides; Polymers; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization

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A polydiacetylene-nested porphyrin conjugate for dye-sensitized solar cells
Pootrakulchote N., Reanprayoon C., Gasiorowski J., Sariciftci N.S., Thamyongkit P.

Abstract
A polydiacetylene (PDA)-nested zinc-porphyrin derivative was prepared and investigated for its potential applicability in dye-sensitized solar cells (DSSCs). Absorption enhancement at 525-625 nm was observed as a proof of successful PDA formation. Cyclic voltammetry analysis suggested the appropriate positions of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) energy levels of the target material for DSSCs. Optimum DSSCs based on the PDA-nested zinc-porphyrin exhibited a short-circuit photocurrent density (Jsc), an open-circuit voltage (Voc) and a fill factor (FF) of 4.2 mA cm-2, 0.7 V and 0.78, respectively, with an overall power conversion efficiency (PCE) of 2.3%. The photovoltage decay analysis also indicated that the electron recombination lifetime of the cells was prolonged as a result of the presence of the PDA-containing C25 alkyl chains in the porphyrin dye system. © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique.
keywords
acetylene derivative; polydiacetylene; porphyrin; unclassified drug; Article; conjugation; cyclic potentiometry; dye sensitized solar cell; electrical equipment; electrochemistry; molecular dynamics; priority journal; synthesis

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Porphyrin containing lipophilic amide groups as a photosensitizer for dye-sensitized solar cells
Gasiorowski J., Pootrakulchote N., Reanprayoon C., Jaisabuy K., Vanalabhpatana P., Sariciftci N.S., Thamyongkit P.

Abstract
In this study, synthesis and investigation of a novel zinc-porphyrin derivative bearing C24-containing amide groups for potential use in dye-sensitized solar cells (DSSCs) are presented. According to absorption spectra and electrochemical data, the target porphyrin has appropriate highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels. The device studies revealed that the DSSCs based on the target porphyrin exhibited higher light harvesting efficiency in the Q-band region and an increased photocurrent, compared to the DSSCs based on a benchmark derivative bearing no alkyl amide groups on the meso-phenyl substituents. The optimum DSSC based on the target porphyrin gave a short-circuit photocurrent density (Jsc), an open-circuit voltage (Voc) and a fill factor (FF) of 5.6 mA cm-2, 0.7 V and 0.78, respectively, with an overall power conversion efficiency (PCE) of 3.1%. © The Royal Society of Chemistry.
keywords
Amides; Dyes; Electron energy levels; Molecular orbitals; Open circuit voltage; Photosensitizers; Porphyrins; Solar cells; Zinc compounds; Electrochemical data; Highest occupied molecular orbital; Light-harvesting; Lowest unoccupied molecular orbital; Overall power conversion efficiency; Phenyl substituents; Short-circuit photocurrent densities; Zinc porphyrins; Dye-sensitized solar cells

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Quaternized chitosan particles as ion exchange supports for label-free DNA detection using PNA probe and MALDI-TOF mass spectrometry
Meebungpraw J., Wiarachai O., Vilaivan T., Kiatkamjornwong S., Hoven V.P.

Abstract
Quaternized chitosan particles are introduced as anion-exchanged captures to be used with a conformationally constrained pyrrolidinyl peptide nucleic acid (acpcPNA) and MALDI-TOF mass spectrometry for DNA sequence analysis. Methylated chitosan (MC) and methylated N-benzyl chitosan (MBzC) particles were obtained by heterogeneous chemical modification of ionically cross-linked chitosan particles via direct methylation and reductive benzylation/methylation, respectively. N,N,N-trimethylchitosan (TMC) and N-[(2-hydroxyl-3-trimethylammonium)propyl]chitosan chloride (HTACC) particles were prepared by ionic cross-linking of quaternized chitosan derivatives, homogeneously modified from chitosan, namely TMC and HTACC, respectively. The particles formed had a size in a sub-micrometer range and possessed positive charge. Investigation by MALDI-TOF mass spectrometry suggested that some quaternized particles in combination with acpcPNA were capable of detecting a single mismatched base out of 9-14 base DNA sequences. Potential application of this technique for the detection of wild-type and mutant K-ras DNA, a gene that mutation is associated with certain cancers, has also been demonstrated. © 2015 Elsevier Ltd. All rights reserved.
keywords
Alkylation; Chemical modification; Chitin; Chitosan; Chlorine compounds; Crosslinking; DNA; Ion exchange; Mass spectrometry; Nucleic acids; Peptides; Cross linked chitosan; DNA sequence analysis; Ionic cross linking; MALDI-TOF mass spectrometry; Peptide nucleic acid; Positive charges; Quaternary ammonium group; Quaternized chitosans; DNA sequences; chitosan; DNA; N-trimethyl chitosan chloride; peptide nucleic acid; adsorption; chemistry; ion exchange; mass spectrometry; procedures; proton nuclear magnetic resonance; staining; synthesis; Adsorption; Chitosan; DNA; Ion Exchange; Peptide Nucleic Acids; Proton Magnetic Resonance Spectroscopy; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Staining and Labeling

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Cleaner alternative liquid fuels derived from the hydrodesulfurization of waste tire pyrolysis oil
Jantaraksa N., Prasassarakich P., Reubroycharoen P., Hinchiranan N.

Abstract
Waste tires are attractive sources for alternative energy due to their long hydrocarbon chains with a high heating value. However, the condensed (volatile portion) pyrolysis oil derived from waste tires contains a relatively large level of sulfur compounds (1.15 wt%), which is not appropriate for use in combustion engines. Therefore, this research aimed to improve the waste tire pyrolysis oil (WTPO) via hydrodesulfurization (HDS) catalyzed by molybdenum (Mo), nickel-Mo (NiMo) or cobalt-Mo supported on alumina (γ-Al2O3). The maximum % sulfur removal (87.8%) was achieved when the reaction was performed at 250 °C for 30 min using a 2 wt% NiMo/γ-Al2O3 catalyst loading based on the WTPO content and 20 bar initial hydrogen pressure. The amount of sulfurous compounds in the waste tire pyrolysis oil was determined using gas chromatography spectroscopy equipped with a flame photometric detector (GC-FPD). The HDS of the WTPO was effective to reduce the sulfurous compounds, especially thiophene and its derivatives. The results from the simulated distillation gas chromatography (GC-SIMDIS) showed that the hydrodesulfurized WTPO (HDS-WTPO) was mainly composed of a light naphtha fraction (ca. 69%). The heating value of the HDS-WTPO (44 MJ/kg) was similar to those for commercial diesel (45 MJ/kg) and gasoline (gasohol) fuels (47 MJ/kg). © 2015 Elsevier Ltd. All rights reserved.
keywords
Alternative fuels; Alumina; Aluminum; Catalysts; Chromatography; Distillation; Gas chromatography; Gasoline; Loading; Oil shale; Pyrolysis; Sulfur; Sulfur compounds; Tires; Waste incineration; Alternative energy; Combustion engines; Flame photometric detectors; High heating values; Hydrocarbon chains; Initial hydrogen pressure; Simulated distillation; Waste tires; Hydrodesulfurization

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The influence of Ni/Nd-based Ziegler-Natta catalyst on microstructure configurations and properties of butadiene rubber
Chatarsa C., Prasassarakich P., Rempel G.L., Hinchiranan N.

Abstract
Neodymium (Nd)-based Ziegler-Natta catalyst has been well known for preparing polybutadiene rubber (BR) containing high, about 98%, cis-1, 4 configuration with extremely low gel content providing superior resistance to low-temperature fatigue and abrasion. However, its cost is more expensive than a conventional nickel (Ni)-based catalyst. The Nd-BR has poor processability with high cold flow due to its high linearity and molecular weight. To compare with a traditional process, the BR produced by Ni-based catalyst has higher level of branching resulting in the better processability, but it contains medium amount of gel. To balance the catalyst cost and the BR properties, this article reported the influence of a solution containing Ni- and Nd-based Ziegler-Natta catalyst (Ni/Nd) using diethyl aluminum chloride and triethyl aluminum as co-catalysts on 1, 3-butadiene (BD) conversion and physical properties of the elastomeric materials based on obtained rubber (Ni/Nd-BR). In the presence of toluene, the increase in the Ni/Nd molar ratio from 0.0/1.0 to 0.4/0.6 yielded Ni/Nd-BR containing cis21, 4 units of 95%-96% with significantly decreasing both levels of vinyl-1, 2 and trans-1, 4 configurations from 0.26% to 0.13% and 4.44% to 3.07%, respectively. When cyclohexane was applied as the reaction media, 100% BD conversion was achieved and the Ni/Nd-BR had very low content of vinyl21, 2 unit (0.07%). The mechanical properties in terms of tensile properties and abrasion resistance of the elastomer based on Ni/Nd-BR having high cis-1, 4 and relatively higher trans21, 4 configurations were superior to elastomers based on commercial BRs produced by using Ni-and Nd-based catalyst systems. © 2015 Wiley Periodicals, Inc.
keywords
Abrasion; Aluminum chloride; Chlorine compounds; Elastomers; Erosion; Molar ratio; Plastics; Polybutadienes; Rubber; Temperature; Tensile properties; Thermal fatigue; Butadiene rubber; Elastomeric materials; Microstructure configurations; Ni-based catalyst; Polybutadiene rubbers; Properties; Superior resistance; Ziegler-Natta catalysts; Catalysts

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Comparative study of natural dolomitic rock and waste mixed seashells as heterogeneous catalysts for the methanolysis of palm oil to biodiesel
Jaiyen S., Naree T., Ngamcharussrivichai C.

Abstract
Natural dolomitic rock and waste mixed seashells were investigated as renewable sources for preparing heterogeneous catalysts for the methanolysis of palm oil to biodiesel as fatty acid methyl esters (FAME) at 60°C and ambient pressure. After calcination at 800°C, the dolomite as the mixed CaO·MgO catalyst possessed smaller CaO crystallites, a higher thermal stability and higher basicity than the pure CaO catalyst derived from the seashells. Although both catalysts gave the FAME yield >98% (w/w), the calcined dolomite exhibited a faster methanolysis rate and higher stability in use than the likewise calcined seashells. The linear correlation of the FAME yield to the amount of CaO phase containing in both catalysts supported that CaO was the active site. The catalyst deactivation was relevant to the formation of calcium glyceroxides. The presence of MgO dispersed in the CaO matrix was important for the superior physicochemical and catalytic properties of the natural dolomite calcined at 800°C. © 2014 Elsevier Ltd.
keywords
Biodiesel; Calcination; Catalyst activity; Catalyst deactivation; Fatty acids; Gas fuel manufacture; Lime; Magnesia; Physicochemical properties; Transesterification; Catalytic properties; Comparative studies; Dolomite; Fatty acid methyl ester; Heterogeneous catalyst; Linear correlation; Mixed oxide; Seashell; Palm oil; biofuel; catalyst; comparative study; dolomite; ester; heterogeneity; lime; physicochemical property; renewable resource; shell

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Effect of modified silica particles with phenyltriethoxysilane on mechanical and thermal properties of natural rubber composites
Tunlert A., Prasassarakich P., Poompradub S.

Abstract
The modification of silica surface by phenyltriethoxysilane (PhTES) as a modifying agent was carried out by sol-gel reaction of tetraethoxysilane (TEOS) as a precursor of silica. The condition to modify silica particles was the use of the mole ratio of TEOS to PhTES of 1:0.4 and ammonia as a catalyst at ambient temperature for 24 h. The characterization of modified silica surface was investigated by a fourier transform infrared spectroscopy and contact angle measurement. The modified silica particles were in a spherical shape, which was confirmed by a scanning electron microscopy. The mechanical properties and thermal stability of modified silica particles filled NR vulcanizates were greatly improved compared to those of unfilled NR vulcanizates due to the reinforcing effect and the high thermal oxidative stability of modified silica particles, respectively. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
keywords
Fourier transform infrared spectroscopy; Rubber; Scanning electron microscopy; Sol-gel process; Sol-gels; Surface reactions; Surface treatment; Thermodynamic stability; Mechanical and thermal properties; Modified silica; Modified silica particles; Natural rubber composites; Phenyltriethoxysilane; Reinforcing effects; Sol-Gel Reaction; Tetraethoxysilanes; Silica

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Preparation of natural rubber-graft-poly(lactic acid) used as a compatibilizer for poly(lactic acid)/NR blends
Sookprasert P., Hinchiranan N.

Abstract
Poly(lactic acid) (PLA) is a biodegradable plastic with good properties in terms of high tensile strength and high tensile modulus, but the brittleness and low impact strength behavior limit its applications. To enhance the impact strength of PLA, natural rubber (NR) with excellent elastic property should be applied to PLA. However, the polarity difference of these constituents leads the incompatibility resulting in poor mechanical properties of PLA/NR blends. Thus, the chemical modification of NR to increase its polarity is required. This research aimed to synthesize NR-graft-PLA (NR-PLA) as a compatibilizer for PLA/NR blends. There were 2 steps to prepare NR-PLA compatibilizer. Firstly, NR was functionalized by various maleic anhydride (MAH) contents (5-20 phr) to produce NR-MAH having higher polarity than NR. Then, NR-MAH was grafted with PLA via esterification using 4-dimethyaminopyridine (DMAP) as a catalyst. The structural characterization of the NR-MAH and NR-PLA was conducted by FT-IR and 1H NMR spectrooscopy. This was observed that the increase in the MAH contents increased the amount of grafted MAH in the NR-MAH structure. The higher grafted MAH content induced the greater efficiency for grafting PLA in preparation of NR-PLA. The effects of DMAP, NR/PLA wt ratio and temperature in the esterification step on the grafted PLA were investigated. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
keywords
Biodegradable polymers; Chemical modification; Compatibilizers; Esters; Fracture mechanics; Graft copolymers; Impact strength; Lactic acid; Rubber; Tensile strength; Biodegradable plastics; Elastic properties; Functionalized; High-tensile strength; ITS applications; Poly lactic acid; Polylactic acids; Structural characterization; Grafting (chemical)

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Preparation of green high impact polystyrene beads via suspension polymerization
Kittiwattanakul T., Prasassarakich P., Hinchiranan N.

Abstract
The aim of this research was to investigate the important effects and their interaction on production of Green High Impact Polystyrene (HIPS) synthesized by using natural rubber (NR) as elastomeric phase via suspension polymerization initiated and stabilized by using benzoyl peroxide (BPO) and poly(vinyl alcohol) (PVA), respectively. The effects of reaction parameters: wt ratio of NR/styrene and PVA/NR including agitation rate on HIPS bead size were studied by using 2k factorial design experiment. The HIPS bead size increased with increasing the NR content (0.01-0.08 w/w of NR/ST) in the mixture of NR/styrene syrup. Whereas, the increase in the PVA content (1.5-2.5 w/w of PVA/NR) and agitation rate (350-450 rpm) decreased HIPS bead size. Thermal gravimetric analysis (TGA) results were showed that HIPS containing the various amounts of NR had more thermal stability than the neat PS. Moreover, the glass transition temperature (Tg) of PS phase in the obtained HIPS bead was shifted from 97.9 to 84.2 °C when the wt ratio of NR/ST was increased to 0.08. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
keywords
Benzoyl peroxide; Gravimetric analysis; Polymerization; Polymers; Polystyrenes; Polyvinyl alcohols; Rubber; Synthesis (chemical); Thermogravimetric analysis; Agitation rates; Elastomeric phase; Factorial design; High impact polystyrene; Poly (vinyl alcohol) (PVA); Reaction parameters; Suspension polymerization; Thermal gravimetric analyses (TGA); Glass transition

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Production of nano-calcium carbonate from shells of the freshwater channeled applesnail, Pomacea canaliculata, by hydrothermal treatment and its application with polyvinyl chloride
Rungpin N., Pavasupree S., Prasassarakich P., Poompradub S.

Abstract
The use of naturally renewable shells of the freshwater channeled applesnail, Pomacea canaliculata, as a filler to replace commercial calcium carbonate (CaCO3) was investigated in this study. Ground P. canaliculata shell particles were converted to nano-CaCO3 particles by the displacement reaction of calcium chloride in sodium carbonate solution followed by hydrothermal treatment at 100°C for 1 h to synthesize nano-CaCO3 with particle sizes of 30-100 nm in diameter. The mechanical properties, in terms of the tensile strength, elongation at brake and impact strength, of polyvinyl chloride (PVC) were greatly improved by mixing with nano-CaCO3 at 5-10 parts per hundred of resin. Additionally, the presence of nano-CaCO3 at the same levels increased the flame resistance and thermal stability of the PVC composite materials. © 2014 Society of Plastics Engineers.
keywords
Calcium; Carbonation; Flame resistance; Impact strength; Polyvinyl chlorides; Substitution reactions; Tensile strength; Thermodynamic stability; Water; Displacement reactions; Hydrothermal treatments; ITS applications; Nano calcium carbonate; Nano-CaCO; Polyvinyl chloride (PVC); Sodium carbonate; Calcium carbonate

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Polyaniline/polyacrylate core-shell composites: Preparation, morphology and anticorrosive properties
Varakirkkulchai P., Kongparakul S., Prasassarakich P.

Abstract
Polyaniline/partially phosphorylated poly(vinyl alcohol)/polyacrylate nanoparticles ((PAn/P-PVA)x/PAcy) were synthesized by encapsulation of varying amounts of PAn/P-PVA nanoparticles (x = 0.3, 0.5 or 0.7 g) with PAc (y = 4, 6 or 8 g acrylate monomers) via emulsifier-free emulsion polymerization. A monomer conversion level of 93.9% was achieved for the synthesis of the (PAn/P-PVA)0.5/PAc4 nanoparticles. X-ray diffraction analysis revealed that PAc was intercalated between the PAn/P-PVA layers, whilst transmission electron microscopy analysis of the different nanoparticles revealed they were spherical PAn/P-PVA agglomerates coated with PAc. Thermogravimetric analysis revealed that the thermal stability of the (PAn/P-PVA)/PAc nanoparticles decreased with increasing amounts of PAc. Cyclic voltammetry based analysis of the different (PAn/P-PVA)/PAc nanoparticles coated onto carbon fiber electrodes revealed that the PAn/P-PVA nanoparticles were encapsulated sufficiently by the non-conductive PAc and that the peak current decreased with increasing amounts of acrylate. With respect to the corrosion resistance in 1.0 M sulfuric acid, steel coated with the (PAn/P-PVA)0.7/PAc8 nanocomposite showed the best corrosion resistance (11.4%), but for the nanocomposites at each PAn/P-PVA loading level, the anticorrosive properties increased with increasing PAc levels, presumably due to the increasing tortuosity of the diffusion pathway through the coating for any corrosion agents. © 2015 Elsevier B.V. All rights reserved.
keywords
Acrylic monomers; Carbon; Carbon fibers; Corrosion; Corrosion protection; Corrosion resistance; Cyclic voltammetry; Diffusion coatings; Emulsification; Emulsion polymerization; Encapsulation; Monomers; Nanocomposites; Nanoparticles; Polyaniline; Polyvinyl alcohols; Synthesis (chemical); Thermodynamic stability; Transmission electron microscopy; X ray diffraction analysis; Acrylate monomers; Anti-corrosive properties; Carbon fiber electrodes; Core-shell composites; Diffusion pathways; Emulsifier-free emulsion polymerization; Monomer conversions; Transmission electron; Thermogravimetric analysis

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1,3-butadiene polymerization using co/nd-based ziegler/natta catalyst: Microstructures and properties of butadiene rubber
Chatarsa C., Prasassarakich P., Rempel G.L., Hinchiranan N.

Abstract
Among Ziegler-Natta catalysts used for 1,3-butadiene (1,3-BD) polymerization, the advantage of a neodymium (Nd)-based catalyst is that it provides butadiene rubber (BR) with a high content of cis-1,4 configuration and a low amount of vinyl-1,2 units. Whereas, a cobalt (Co)-based catalyst can produce BR with a low content of trans-1,4 configuration. Thus, this research was aimed to prepare BR containing a high content of cis-1,4 configuration with low amounts of both trans-1,4 and vinyl-1,2 units using a combination of Nd-and Co-based Ziegler/Natta catalysts with triethyl aluminum (TEAL) and diethyl aluminum chloride (DEAC) acting as a co-catalyst and a chlorinating agent, respectively. The effects of the molar Co/Nd ratio, TEAL concentration, DEAC loading, 1,3-BD content, solvent type, and reaction temperature on %conversion, microstructures, molecular weight, and molecular weight distribution of the obtained BR (Co/Nd-BR) were evaluated. The Co/Nd-BR having >97% of cis-1,4 configuration, <2% of trans-1,4 structure, and <1% of vinyl-1,2 unit with >80% conversion was achieved when 3.01 M of 1,3-BD concentration was treated in a toluene/cyclohexane mixture (7/3 [w/w]). The Co/Nd-BR exhibited no gel formation with high mechanical performance, which was equivalent to commercial BR produced from a Nd-based catalyst system. © 2014 Society of Plastics Engineers.
keywords
Aluminum; Aluminum chloride; Butadiene; Catalysts; Microstructure; Molecular weight distribution; Polymerization; Rubber; Butadiene rubber; Catalyst system; Chlorinating agents; Mechanical performance; Microstructures and properties; Neodymiums (Nd); Reaction temperature; Ziegler-Natta catalysts; Loading

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