bluuebunny/crossref_metadata_2025_split huggingface dataset:
Green strength enhancement in BIIR/Olefin copolymer compounds
Authors: Tsou Andy H. , Duvdevani Ilan , Datta Sudhin 
Published: September 2006

AbstractImproved green strength of halobutyl at elevated temperatures was obtained via blending with semicrystalline polymers. For such improvement, a judicious selection of olefin copolymers, such as ethylene–propylene, ethylene–butene, or ethylene–octene copolymers, as blend components has to be made. Green strength enhancement was found to increase with increasing compatibility between bromobutyl (BIIR) and the olefin copolymer. Increased compatibility may be estimated by chain dimension similarity in a dilute solution between polyisobutylene and the olefin copolymer. For the most compatible olefin copolymer examined, a propylene elastomer, a phase percolation threshold was found at 0.13 volume fraction of the copolymer. This threshold value is lower than the theoretical limit of 0.156 for spherical phase domains. Based on the morphological examination by tapping phase AFM, it was found that this propylene elastomer crystallizes around the carbon black filler agglomerates to form nonspherical and high‐aspect‐ratio dispersed phases. Its phase anisotropy may contribute to its lower phase percolation threshold in BIIR compounds. Model innerliner compounds of BIIR containing 10–20 phr of such a propylene elastomer in place of natural rubber were shown to have excellent room‐temperature and improved elevated‐temperature green strengths, good aging resistance, and excellent impermeability without significant increases in relaxation time. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4447–4459, 2006
Synthesis and characterization of poly(ethylene glycol dimethacrylate–1‐vinyl‐1,2,4‐triazole) copolymer beads for heavy‐metal removal
Authors: Uzun Lokman , Kara Ali , Tüzmen Nalan , Karabakan Abdülkerim , Beşirli Necati , Denizli Adil 
Published: September 2006

AbstractWe prepared poly(ethylene glycol dimethacrylate–1‐vinyl‐1,2,4‐triazole) [poly(EGDMA–VTAZ)] beads (average diameter = 150–200 μm) by copolymerizing ethylene glycol dimethacrylate (EGDMA) with 1‐vinyl‐1,2,4‐triazole (VTAZ). The copolymer composition was characterized by elemental analysis and found to contain five EGDMA monomer units for each VTAZ monomer unit. The poly(EGDMA–VTAZ) beads had a specific surface area of 65.8 m2/g. Poly(EGDMA–VTAZ) beads were characterized by Fourier transform infrared spectroscopy, elemental analysis, surface area measurements, swelling studies, and scanning electron microscopy. Poly(EGDMA–VTAZ) beads with a swelling ratio of 84% were used for the heavy‐metal removal studies. The adsorption capacities of the beads for Cd(II), Hg(II), and Pb(II) were investigated in aqueous media containing different amounts of these ions (5–750 mg/L) and at different pH values (3.0–7.0). The maximum adsorption capacities of the poly(EGDMA–VTAZ) beads were 85.7 mg/g (0.76 mmol/g) for Cd(II), 134.9 mg/g (0.65 mmol/g) for Pb(II), and 186.5 mg/g (0.93 mmol/g) for Hg(II). The affinity order toward triazole groups on a molar basis was observed as follows: Hg(II) > Cd(II) > Pb(II). pH significantly affected the adsorption capacity of the VTAZ‐incorporated beads. The equilibrium data were well fitted to the Redlich–Peterson isotherm. Consideration of the kinetic data suggested that chemisorption processes could have been the rate‐limiting step in the adsorption process. Regeneration of the chelating‐beads was easily performed with 0.1M HNO3. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4276–4283, 2006
Curing behavior and thermal mechanical properties of cyanate ester blends
Authors: Koh Henry C. Y. , Dai Jie , Tan Eileen 
Published: September 2006

AbstractCyanate esters are a class of important thermally resistant polymers. To tailor their processability and thermomechanical properties, a series of cyanate ester blends based on a trifunctional novolac cyanate ester (HF‐5), a difunctional bisphenol E cyanate ester (HF‐9), and a reactive catalyst [2,2′‐diallyl bisphenol A (DBA)] were formulated. The effect of the blend composition on the rheology and curing behavior of these cyanate ester blends and the corresponding thermal and mechanical properties of the cured cyanate ester blends was studied. The results showed that HF‐5 contributed to good mechanical property retention at high temperatures because of its trifunctionality, whereas HF‐9 imparted processability by reducing the viscosity and extending the pot life of the formulated cyanate ester blends at the processing temperature. On the basis of the results, an optimal cyanate ester blend suitable for resin transfer molding was determined: the HF‐5/HF‐9/DBA weight ratio of 80 : 15 : 5 exhibited good processability and thermomechanical properties. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4284–4290, 2006
Optimization of synthetic conditions of a novel collagen‐based superabsorbent hydrogel by Taguchi method and investigation of its metal ions adsorption
Authors: Pourjavadi A. , Salimi H. , Amini‐Fazl M. S. , Kurdtabar M. , Amini‐Fazl A. R. 
Published: September 2006

AbstractA novel biopolymer‐based superabsorbent hydrogel was synthesized through chemical crosslinking by graft copolymerization of partially neutralized acrylic acid onto the hydrolyzed collagen, in the presence of a crosslinking agent and a free radical initiator. The Taguchi method, a robust experimental design, was employed for the optimization of the synthesis reaction based on the swelling capacity of the hydrogels. This method was applied for the experiments and standard L16 orthogonal array with three factors and four levels were chosen. The critical parameters that have been selected for this study are crosslinker (N,N′‐methylene bisacrylamide), initiator (potassium persulfate), and monomer (acrylic acid) concentration. From the analysis of variance of the test results, the most effective factor to control equilibrium swelling capacity was obtained and maximum water absorbency of the optimized final product was found to be 500 g/g. The surface morphology of the gel was examined using scanning electron microscopy. Furthermore, the sorption capacity of the hydrogel toward bivalent metal ions was evaluated. Therefore, the hydrogel may be considered as a candidate to develop as an efficient biopolymer‐based chelating hydrogel for water treatment. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4878–4885, 2006
Accelerated aging versus realistic aging in aerospace composite materials. I. The chemistry of thermal aging in a low‐temperature‐cure epoxy composite
Authors: Dao B. , Hodgkin J. , Krstina J. , Mardel J. , Tian W. 
Published: September 2006

AbstractSamples of an aerospace‐grade epoxy composite (M20/IM7) are subject to long‐term (∼ 1 year) thermal aging at temperatures of 70°C, 120°C, 170°C, and 200°C (in air) and the changes to the chemical and physicochemical structure of the composite are analyzed by a range of different techniques, including gravimetric analysis, FTIR, DSC, and DMA to compare the effects of different severities of degradation treatment. The results show that at the lower temperatures, the oxidative degradation changes are very selective for chemical defect groups, particularly near the sample surfaces. However, at the higher temperatures, combinations of further cure reactions and generalized oxidative degradation changes (again from the surface inwards) make for a highly complex ageing pattern for this particular composite material. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4291–4303, 2006
Weathering, water absorption, and durability of silicon, acetylated, and heat‐treated wood
Authors: Temiz Ali , Terziev Nasko , Jacobsen Bjørn , Eikenes Morten 
Published: September 2006

AbstractIn this study, two colloidal dispersions of pure amorphous silicon dioxide particles, acetylated, and heat‐treated samples were tested for a possible application as a wood protection agents. The silicon, acetylated, and heat‐treated samples were exposed to an accelerated weathering experiment, and their dimensional stability was assessed. The weathering experiment comprised cycles of 2 h UV‐light irradiation followed by water spray for 18 min. The surface changes of the weathered samples were characterized by FT‐IR spectroscopy and color measurements. According to results, the silicon treatments showed lower color changes than untreated ones. However, acetylated and heat‐treated samples provided the lowest color changes. The resistance of the silicon, acetylated, and heat‐treated wood to decay was studied by means of brown and white rot fungi in laboratory decay tests. Decay test results revealed that acetylated and heat‐treated wood samples showed better decay resistance against P. placenta and C. versicolor than silicon treatments. Samples modified with silicon were exposed in above ground standard lap‐joint test in Ultuna, Sweden. The dispersions of pure amorphous silicon dioxide impregnated in wood did not significantly influence its hygroscopic and dimensional behavior. However, the silicon treatment reduced the color changes caused by weathering. The silicon impregnated samples showed a weak fungal discoloration similar to that of chromated copper arsenate impregnated controls in above ground standard lap‐joint test. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4506–4513, 2006
Waste natural gum as a multifunctional additive in rubber
Authors: Guhathakurta S. , Anandhan S. , Singha Nikhil K. , Chattopadhyay R. N. , Bhowmick Anil K. 
Published: September 2006

AbstractBahera gum, extracted from the bark of Terminalia bellerica, is a waste material. The present study involves the use of this natural gum as a multifunctional additive in natural rubber (NR) and brominated isobutylene‐co‐paramethyl styrene (BIMS). Fourier transform infrared (FTIR) analysis was employed to study the functional groups present in the gum. It was found that fatty acids/esters in the gum act as accelerator activator and can replace stearic acid in rubber formulations. Polyphenols in the gum act as antioxidant and the action is comparable with the commercial antioxidant 2,2,4‐trimethyl‐1,2‐dihydroquinoline (TQ) in natural rubber. The gum improves the tack strength of the rubbers (21% at 2.5 phr loading for NR and 54% at 10 phr loading for BIMS). The gum imparts plasticization effect which is reflected in the reduction in k and enhancement in n values, the exponents in the power law equation, with increasing gum concentration. The activation energy of flow is also reduced with the addition of the gum. Moreover, it decreases the elastic memory of the system which causes reduction in die swell. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4897–4907, 2006
Synthesis and characterization of functional copolymers of citronellol and acrylamide
Authors: Srivastava A. K. , Pandey Prachi , Mishra Garima 
Published: September 2006

AbstractThe radical copolymerization of citronellol with acrylamide in xylene at (80 ± 10)°C for 1 h in the presence of benzoylperoxide follows ideal kinetics with bimolecular termination and results in the formation of an alternating copolymer as evidenced from the values of reactivity ratios as r1 (acrylamide) = 0.0045 and r2 (citronellol) = 0.0005, which have been calculated by Kelen–Tüdos method. The overall activation energy is computed as 44 kJ/mol. The IR spectrum of the copolymer shows the presence of bands at 3427 cm−1 due to alcoholic group and 1710 cm−1 due to amide group. The 1H NMR spectrum of the copolymer shows peaks between 6.3 and 7δ due to amide group (> CO stretching) and between 7 and 7.7δ due to alcoholic group. The values of Mark–Houwink constant for present copolymer system have been evaluated as α = 0.33 and K = 2.3 × 10−1 with the help of gel permeation chromatography. The Alfrey‐price, Q–e parameters for citronellol have been calculated as 0.43 and 1.07. The copolymer is highly thermally stable and has a glass transition temperature (Tg) of 102°C as evaluated from differential scanning calorimetry studies. The mechanism has also been elucidated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4908–4914, 2006
Preparation and characterization of polystyrene–poly(ethylene oxide) amphiphilic block copolymers via atom transfer radical polymerization: Potential application as paper coating materials
Authors: Ibrahim Khalid , Salminen Arto , Holappa Susanna , Kataja Kirsi , Lampinen Henna , Löfgren Barbro , Laine Janne , Seppälä Jukka 
Published: September 2006

AbstractPoly(ethylene oxide) (PEO) monochloro macroinitiators or PEO telechelic macroinitiators (Cl‐PEO‐Cl) were prepared from monohydroxyfunctional or dihydroxyfunctional PEO and 2‐chloro propionyl chloride. These macroinitiators were applied to the atom transfer radical polymerization of styrene (S). The polymerization was carried out in bulk at 140°C and catalyzed by Copper(I) chloride (CuCl) in the presence of 2,2′‐bipyridine (bipy) ligand (CuCl/bipy). The amphiphilic copolymers were either A‐B diblock or A‐B‐A triblock type, where A block is polystyrene (PS) and B block is PEO. The living nature of the polymerizations leads to block copolymers with narrow molecular weight distribution (1.072 < Mw/Mn < 1.392) for most of the macroinitiators synthesized. The macroinitiator itself and the corresponding block copolymers were characterized by FTIR, 1H NMR, and SEC analysis. By adjusting the content of the PEO blocks it was possible to prepare water‐soluble/dispersible block copolymers. The obtained block copolymers were used to control paper surface characteristics by surface treatment with small amount of chemicals. The printability of the treated paper was evaluated with polarity factors, liquid absorption measurements, and felt pen tests. The adsorption of such copolymers at the solid/liquid interface is relevant to the wetting and spreading of liquids on hydrophobic/hydrophilic surfaces. From our study, it is observed that the chain length of the hydrophilic block and the amount of hydrophobic block play an important role in modification of the paper surface. Among all of block copolymers synthesized, the PS‐b‐PEO‐b‐PS containing 10 wt % PS was found to retard water absorption considerably. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4304–4313, 2006
Microencapsulation of water‐soluble flame retardant containing organophosphorus and its application on fabric
Authors: Lin Miao , Yang Yong , Xi Ping , Chen Shui‐lin 
Published: September 2006

AbstractMicroencapsulation is based on multiple emulsion interfacial reaction technique that combines the characteristics of the interfacial reaction and conventional multiple‐emulsion processes. In this study, the microcapsules were synthesized with the water‐soluble dimethyl methyl phosphorate (DMMP) as the core material and the acetal product of polyvinyl alcohol (PVA) and glutaraldehyde (GA) as the shell material. The microcapsules were characterized by using DSC, IR spectrum and phosphorus qualitative analysis, and the factors affecting microencapsulation were identified and discussed. The data presented herein suggested that the size distribution of microcapsules was affected by the concentration of PVA and SPAN80 and by the phase volume ratio, while the crosslinking agent GA content has little effect. The data also showed that the microcapsules with the core of flame retardant containing organophosphorus would have promising applications in inflaming retarding of cotton fabric. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4915–4920, 2006
Antimicrobial poly(N‐vinyl‐2‐pyrrolidone‐alt‐maleic anhydride)/poly(ethylene imine) macrocomplexes
Authors: Temiz Ayhan , Özmen Toğay Sine , Şener Ayla , Güven Güldem , Rzaev Zakir M. O. , Piskin Erhan 
Published: September 2006

AbstractThe antimicrobial polymer/polymer macrocomplexes were synthesized by radical alternating copolymerization of N‐vinyl‐2‐pyrrolidone with maleic anhydride [poly(VP‐alt‐MA)] with 2,2′‐azobis‐isobutyronitrile as an initiator at 65°C in dioxane solutions under nitrogen atmosphere, and interaction of prepared copolymer with poly(ethylene imine) (PEI) in aqueous solutions. The susceptibility of some Gram‐negative (Salmonella enteritidis and Escherichia coli) and Gram‐positive (Staphylococcus aureus and Listeria monocytogenes) bacteria to the alternating copolymer and its PEI macrocomplexes with different compositions in microbiological medium was studied using pour‐plate technique. All the studied polymers, containing biologically active moieties in the form of ionized cyclic amide, and macrobranched aliphatic amine groups and acid/amine complexed fragments, were more effective against L. monocytogenes than those for Gram‐positive S. aureus bacterium. This fact was explained by different surface layer structural architectures of biomacromolecules of tested bacteria. The resulting polymeric antimicrobial materials are expected to be used in various areas of medicine and food industry. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:5841–5847, 2006
Electrorheological properties of chemically modified chitosan suspension with various functional pendants
Authors: Ko Young Gun , Choi Ung Su 
Published: September 2006

AbstractIn this study, functional pendants of chitosan were focused on enhancing the shear stress of electrorheological (ER) fluids. Chitosan succinates and chitosan phthalate were synthesized for ER particles and ER fluids were prepared by dispersing the particles in silicone oil. After comparing the shear stress of all prepared ER fluids, obtained conclusions were that ER particle having two functional groups (one is +ve charge and another is −ve charge) showed higher shear stress than that having only one functional group like the comparison between chitosan succinate(I) and chitosan succinate(II). However, though expect of the intermolecular overlapping between the π electrons clouds supporting the charge carrier generation and transport leading to a significant delocalization of electrons, chitosan phthalate shows lower shear stress than chitosan succinate(I) and chitosan succinate(II). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4937–4942, 2006
Structure and properties of PMP foams doped with Cu nanopowders
Authors: Du K. , Zhang L. , Luo X. , Yin Q. 
Published: September 2006

AbstractPoly‐4‐methyl‐1‐pentene (PMP) foams doped with Cu nanopowders have been prepared by thermally induced phase separation. Ultrasonic dispersal was exploited to increase dispersion uniformity of Cu nanopowders in the foam skeleton. With increase in the concentration of Cu nanopowders, the structure of the doped PMP foams becomes finer and the size of cells, smaller. The modulus data of the doped foams described by a scaling constant larger than two significantly overestimate the predicted value. These indicate two roles of Cu nanopowders in PMP foams: fortifiers of foam structure and nuclei in polymer crystallization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5627–5632, 2006
Preparation of novel acrylate‐based liquid crystalline polymers and the photoinduced alignment behavior of their films
Authors: Zhu Jun , Wu Li‐Ping , Zhang Yu‐Ying , Jin Xi , He Shang‐Jin , Shi Ke‐Yu , Guo XianZhi , Du Zong‐Jie , Zhang Bao‐Long 
Published: September 2006

AbstractTwo acrylate monomers containing both mesogenic biphenyl group and photoreactive cinnamoyl group as well as different length of flexible spacers (i.e., n‐[4′‐(n‐cinnamoyloxyalkoxy)biphenyl‐4‐yloxy]alkyl acrylate, n = 4 (A4OO4C) and 6 (A6OO6C)) were synthesized for the first time. Their corresponding polymers (i.e., PA4OO4C and PA6OO6C) were obtained by free radical polymerization using AIBN as an initiator. The monomer A4OO4C showed smectic liquid crystalline phase and a clear fan texture was observed under optical polarizing microscope. However, no liquid crystalline phase was found for A6OO6C. In contrast, PA4OO4C showed no liquid crystalline phase while PA6OO6C showed a clear nematic schlieren texture during the cooling process. The optical polarized microscope of E5 cast on the top of the polymer film also showed the alignment. Furthermore, the irradiation of the polymer films by LP‐UV light led to the cycloaddition of the cinnamoyl groups, resulting in the simultaneous alignment of the biphenyl groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4565–4572, 2006
Optical properties of MEH‐PPV conjugated polymer covered by silica nanoshells
Authors: Sáfar G. A. M. , Oliveira F. A. C. , Cury L. A. , Righi A. , Barbosa P. L. M. , Dieudonné P. , Lameiras F. S. 
Published: September 2006

AbstractPoly [2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylene vinylene] (MEH‐PPV) covered by nanostructured silica shells were synthesized via sol–gel process and investigated after freeze‐drying and heat‐drying in vacuum. The freeze‐dried sample consists of a light pink powder while the heat‐dried sample presents a redder coarse‐grained material. The freeze‐dried sample was analyzed using small angle X‐ray scattering (SAXS). Both samples were analyzed using photoluminescence (PL) and Raman spectroscopy at room temperature. The PL spectra presented relatively large red shifts compared with that of the MEH‐PPV in tetrahydrofuran solution, which was taken as a reference sample. The energy shifts observed in the PL and Raman spectra strongly support an explanation based on denser packing conditions inside the nanostructured silica shells, which can effectively lead the polymer molecules to a higher interchain interaction via aggregate sites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5620–5626, 2006
Dispersion copolymerization of acrylonitrile‐vinyl acetate in supercritical carbon dioxide
Authors: Yang Yajun , Dong Qingzhi , Wang Zi , Shen Cuihui , Huang Zhengfeng , Zhu Hui , Liu Tao , Hu Chun Pu 
Published: September 2006

AbstractDispersion copolymerization of acrylonitrile‐vinyl acetate (AN‐VAc) had been successfully performed in supercritical carbon dioxide (ScCO2) with 2,2‐azobisisobutyronitrile (AIBN) as a initiator and a series of lipophilic/CO2‐philic diblock copolymers, such as poly(styrene‐r‐acrylonitrile)‐b‐poly(1,1,2,2‐tetrahydroperfluorooctyl methacrylate) (PSAN‐b‐PFOMA), as steric stabilizers. In dispersion copolymerization, poly(acrylonitrile‐r‐vinyl acetate) (PAVAc) was emulsified in ScCO2 effectively using PSAN‐b‐PFOMA as a stabilizer. Compared with the precipitation polymerization (absence of stabilizer), the products prepared by dispersion polymerization possessed of higher yield and higher molecular weight. In addition, the particle morphology of precipitation polymerization was irregular, but the particle morphology of dispersion polymerization was uniform spherical particles. In this study, the effects of the initial concentrations of monomer and the stabilizer and the initiator, and the reaction pressure on the yield and the molecular weight and the resulting size and particle morphology of the colloidal particles were investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5640–5648, 2006