bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodegradation of poly(L‐aspartic acid‐co‐valine) and its derivatives
Authors: Tang Guping , He Binbin 
Published: July 2006

AbstractBiodegradable poly(L‐aspartic‐acid/valine) (PAV) was synthesized by thermal polycondensation. The molar ratios of aspartic acid/valine were 9 : 1, 8 : 2, 7 : 3, 6 : 4, and 5 : 5, respectively. The chemical structure of PAV was confirmed by 13C‐NMR, DSC, FTIR, X‐ray, and GPC measurements. The degradation of PAV was studied in PBS buffer solution (pH 7.4 and 8.2) and in aqueous solution with enzymatic hydrolysis in which papain and trypsine acted as catalyst. It showed that the biodegradation rate of PAV was increased when the content of valine in copolymer increased. 3‐Hydroproplamine was used in a succinimide ring‐open reaction to obtain hydrophilic products (PHPAV). Stability tests showed that humidity, light, and temperature had no remarkable effect on PHPAV, however, it could be degraded in base solution. Biocompatibility and hematological tests were investigated. No deaths were found in the mice treated with PHPAV solution up to a 7.5 g/kg dose. No differences in number of red cells and glutamic pyruvic and creatinuria transaminase activities were found between the experiment and the control groups. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 46–51, 2006
Effect of selected boroorganic compounds on thermal and heat properties of rigid polyurethane–polyisocyanurate foams
Authors: Czupryński Bogusław , Liszkowska Joanna , Paciorek‐Sadowska Joanna 
Published: July 2006

AbstractThe effects of three selected borates {tri(hydroxypropyl), tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)‐1‐methylethyl], tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)propyl]} on the heat and thermal properties of rigid polyurethane–polyisocyanurate foams was studied. Increasing the amount of tri(hydroxypropyl) borate and tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)propyl] borate in the foam composition from 0.1 to 0.4 chemical equivalents caused an increase in the softening point, the temperature of the first decrement of foam mass, the extrapolated temperature of the main decrement of the foam mass, and the temperature of the highest rate of the mass decrement. When tri[(3‐chloro‐2‐hydroxy‐1‐propoxy)‐1‐methylethyl] borate was added to the foam compositions, the softening point decreased but the temperatures characterizing their thermal resistance were higher in comparison with the standard foam. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 768–771, 2006
4,4′‐Bismaleimidodiphenyl methane modified novolak resin/titania nanocomposites: Preparation and properties
Authors: Lu Guotao , Huang Ying , Yan Yehai , Zhao Tong , Yu Yunzhao 
Published: July 2006

Abstract4,4′‐Bismaleimidodiphenyl methane modified novolak resin/titania nanocomposites were prepared by the sol–gel process of tetrabutyl titanate in the presence of 4,4′‐bismaleimidodiphenyl methane modified novolak resin prepolymers with acetyl acetone as a stabilizer. These nanocomposite materials were characterized by Fourier transform infrared analysis, dynamical mechanical analysis, thermogravimetric analysis, transmission electron microscopy, and field emission scanning electron microscopy. Nanometer titania particles were formed in the novolak resin matrix, and the average original particle size of the dispersed phase in the nanocomposites was less than 150 nm, but particle aggregates of larger size existed. The introduction of the titania inorganic phase with a nanoscale domain size did not improve the glass‐transition temperature of the nanocomposites but lowered the thermal resistance of the material because of the incomplete removal of acetyl acetone coordinated with tetrabutyl titanate, and it improved the modulus of the material at lower temperatures (<200°C) but lowered the modulus at higher temperatures (>250°C). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 52–57, 2006
Bound rubber in chlorobutyl compounds: Influence of filler type and storage time
Authors: Sridhar V. , Gupta B. R. , Tripathy D. K. 
Published: July 2006

AbstractBound rubber (BdR) is considered as a measure of the filler–polymer interaction in rubber compounds. The variation of the BdR content with storage time was studied in chlorobutyl compounds filled with fillers like carbon black, carbon–silica dual phase filler (CSDPf), silica, and nanoclays. The effect of the addition of a silane coupling agent on the BdR in carbon black and silica filled compounds was also studied. The BdR content increased with storage time in all compounds. The increase in BdR was higher during the initial 15 days of storage. Thereafter there was only a marginal increase. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 715–720, 2006
Preparation and characterization of highly swelling smart grafted polymer networks of poly(vinyl alcohol) and poly(acrylic acid–co–acrylamide)
Authors: Shukla Sandeep , Bajpai A. K. 
Published: July 2006

AbstractSmart grafted polymer networks comprising random copolymer of poly(acrylic acid‐co‐acrylamide) and polyvinyl alcohol and exhibiting extraordinary water imbibtion property were prepared by free radical polymerization method and characterized by Fourier Transform infrared spectroscopy, Ultra Violet spectroscopy, Environmental Scanning Electron Microscopy, Thermogravimetric Analysis, Differential Scanning Calorimetry, and X–ray Diffraction. The mesh size (ξ) and chain flexibility factor (α) of interpenetrating polymer networks were calculated for various grafted polymer network compositions and correlated with their water sorption capacity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 84–95, 2006
Flame‐retardant ABS resins from novel phenyl isocyanate blocked novolac phenols and triphenyl phosphate
Authors: Ji Youngyoun , Kim Jinhwan , Bae Jin‐Young 
Published: July 2006

AbstractIn an effort to prepare a novel novolac phenol (NP) based char former with good solubility, the hydroxyl functionalities of NP were blocked with phenyl isocyanate (PI) via a simple urethane‐forming reaction. The chemical structure and properties of the obtained novolac phenol–phenyl isocyanate adduct (NP–PI) were characterized with gel permeation chromatography, Fourier transform infrared spectroscopy, 1H‐NMR, and differential scanning calorimetry. Adducts of two kinds of NPs (molecular weights = 450 and 800) with PI were used as potential char formers for this study. Thus, a two‐component system using NP–PI as a char former and triphenyl phosphate (TPP) as a phosphorous‐based flame retardant was blended with ABS, and the thermal degradation behavior and flame retardance were examined as a function of the molar mass of NP–PI and the TPP/NP–PI ratio with thermogravimetric analysis and limiting oxygen index (LOI) testing. ABS compositions with no NP–PI were also prepared for comparison. The mixtures showed a synergistic effect between TPP and NP–PI on the flame‐retardance enhancement of ABS. Those containing the higher molar mass NP–PI adduct were the most flame retardant, and a LOI value as high as 41 was obtained. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 721–728, 2006
Pulverization of rubber using modified solid state shear extrusion process (SSSE)
Authors: Shahidi Nima , Arastoopour Hamid , Ivanov George 
Published: July 2006

AbstractThe challenge of reusing scrap rubber material is mainly due to its crosslinked/vulcanized structure, which prevents the material from melting and from being melt processed into new items. The most feasible recycling approach is believed to be a process in which the vulcanized rubber is first pulverized into a fine powder and then incorporated into new products. Solid state shear extrusion (SSSE), developed at Illinois Institute of Technology, is a process for continuous pulverization of rubber materials into a fine powder (Aratoopour, H. U.S. Pat. 5,704,555 (1998); Arastoopour, H.; Schocke, D. A.; Bernstein, B.; Bilgili, E. U.S. Pat. 5,904,885 (1999); Ivanov, G. Polym Eng Sci 2000, 40, 676). In this work, the design of the SSSE apparatus was modified to overcome heat generation due to pulverization and the limitation from the torque/feeding rate relation and, thus, to increase the efficiency of the process in the production of finer particles at higher throughput. The modification was achieved by separating the original process into the extrusion section and the pulverization section. The extrusion section is dedicated to convey material to the pulverization section, which consists of a cylindrical housing and a rotatable cylindrical element that rotates independent of the extruder's screw. The rotatable cylindrical element can be treaded or flightless. Both sections are connected with an adapter. This new approach to the design allowed us to apply a more efficient cooling system, capable of removing the heat of pulverization and, in turn, results in the production of finer rubber particles. Furthermore, separation of the conveying process from the pulverization process resulted in a reduction in extruder's torque and a significant increase in the throughput. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 119–127, 2006
Physico‐mechanical, dynamic mechanical, and swelling properties of sodium chloride filled chlorobutyl vulcanizates
Authors: Sridhar V. , Tripathy D. K. 
Published: July 2006

AbstractThe effect of addition of rigid, nonreinforcing, and noninteracting filler viz. finely ground NaCl in chlorobutyl vulcanizates on properties such as physicomechanical, dynamic mechanical, and swelling has been studied. The nonreinforcing effect of NaCl in the system was studied by Russel and Cunnenn analysis and Kraus plots. Mechanical measurements of stress and strain at the break of filled and unfilled samples showed no appreciable change in the mechanical behavior of the system. The dynamic mechanical analysis showed that there is no change at all in the glass transition temperature with addition of NaCl filler. The damping properties showed an increase with increase in filler loading because of the filler–filler friction. The swelling behavior of NaCl‐filled CIIR was studied for a period of 60 days in four different solvents of varying chemical energy potential viz. water, chloroform, acetone, and tetrahydrofuran (THF). The degree of swelling was found to increase continuously with time in water, which is a good solvent for the filler, and in THF, which is a good solvent for the polymer matrix. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 707–714, 2006
Synthesis of crosslinked oxidized starch and its adsorption behavior for calcium ion
Authors: Chen Yanxiao , Wang Gongying 
Published: July 2006

AbstractCornstarch, after crosslinking with epichlorohydrin (4%, v/w, dry basis of the starch), was oxidized with hydrogen peroxide over the catalyst Cu(II). The newly synthesized products were applied to examine the calcium ion removal activity from water, under various conditions. Removal efficiency of calcium ion from aqueous solution increased proportionally with carboxyl content and the dose of crosslinked oxidized starch in the solution. Ionization of carboxyl groups in starch was necessary for the effective calcium removal. When the pH of the solution was adjusted below 4.0, the starch was no longer an effective calcium‐sequestering agent. Adsorption isotherm models were developed, wherein the best fit was obtained in the Langmuir model. Thermodynamic study indicated that the adsorption process was exothermic, and the enthalpy change (ΔHθ), the entropy change (ΔSθ), and free energy change (ΔGθ) of the adsorption process were calculated with adsorption isotherm data and basic thermodynamic relations. It was assessed that adsorption occurred by strong electrostatic interactions with the negative adsorption enthalpy (ΔHθ). The regeneration and reusability of oxidized starch were also assessed and were found to retain the adsorption capacity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1539–1546, 2006
Preparation and characterization of rare earth complex europium3+‐acrylate‐1,10‐phenanthroline grafted onto polypropylene
Authors: Pan Yuanfeng , Zheng Anna , Xiao Huining , Hu Fuzeng 
Published: July 2006

AbstractRare earth (RE) complex photoluminescence films were conventionally prepared by blending. The RE complexes were unevenly dispersed in the polymer matrix, thus readily quenching the fluorescence. An improved approach for preparing photoluminescence films was developed, in which the chemical or covalent bonding between the RE complex and polymer was introduced through melt‐grafting polymerization. An RE complex (europium3+‐acrylate‐1,10‐phenanthroline) [Eu(AA)3phen] was synthesized, and then grafted onto polypropylene (PP) in the melt phase to render the resin fluorescently active. The complex and the grafted PP were systematically characterized using various analytical tools including elemental analysis, TGA, IR DSC, WAXS, and fluorescence. The results indicated that the complex possessed favorable fluorescence and thermal stability, and the Eu(AA)3phen complex was successfully grafted onto the PP backbone. The findings from the DSC and WAXS measurements revealed that the complex acted as a nucleating agent, increasing the crystallization rate effectively and destroying the integrity of the crystallinity as well. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1547–1552, 2006
Physical and electrochemical characterizations of poly(vinylidene fluoride‐co‐hexafluoropropylene)/SiO2‐based polymer electrolytes prepared by the phase‐inversion technique
Authors: Kim Kwang Man , Park Nam‐Gyu , Ryu Kwang Sun , Chang Soon Ho 
Published: July 2006

AbstractHighly porous poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVdF–HFP)‐based polymer membranes filled with fumed silica (SiO2) were prepared by a phase‐inversion technique, and films were also cast by a conventional casting method for comparison. N‐Methyl‐2‐pyrrolidone as a solvent was used to dissolve the polymer and to make the slurry with SiO2. Phase inversion occurred just after the impregnation of the applied slurry on a glass plate into flowing water as a nonsolvent, and then a highly porous structure developed by mutual diffusion between the solvent and nonsolvent components. The PVdF–HFP/SiO2 cast films and phase‐inversion membranes were then characterized by an examination of the morphology, thermal and crystalline properties, absorption ability of an electrolyte solution, ionic conductivity, electrochemical stability, and interfacial resistance with a lithium electrode. LiPF6 (1M) dissolved in a liquid mixture of ethylene carbonate and dimethyl carbonate (1:1 w/w) was used as the electrolyte solution. Through these characterizations, the phase‐inversion polymer electrolytes were proved to be superior to the cast‐film electrolytes for application to rechargeable lithium batteries. In particular, phase‐inversion PVdF–HFP/SiO2 (30–40 wt %) electrolytes could be recommended to have optimum properties for the application. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 140–148, 2006
Synthesis of star‐shaped poly(ϵ‐caprolactone) by samarium‐based tetrafunctional initiator and its dilute‐solution properties
Authors: Xi Xiujuan , Jiang Liming , Ling Jun , Sun Weilin , Shen Zhiquan 
Published: July 2006

AbstractAn in situ–generated tetrafunctional samarium enolate from the reduction of 1,1,1,1‐tetra(2‐bromoisobutyryloxymethyl)methane with divalent samarium complexes [Sm(PPh2)2 and SmI2] in tetrahydrofuran has proven to initiate the ring‐opening polymerization of ϵ‐caprolactone (CL) giving star‐shaped aliphatic polyesters. The polymerization proceeded with quantitative conversions at room temperature in 2 h and exhibited good controllability of the molecular weight of polymer. The resulting four‐armed poly(ϵ‐caprolactone) (PCL) was fractionated, and the dilute‐solution properties of the fractions were studied in tetrahydrofuran and toluene at 30°C. The Mark–Houwink relations for these solvents were [η] = 2.73 × 10−2Mw0.74 and [η] = 1.97 × 10−2Mw0.75, respectively. In addition, the unperturbed dimensions of the star‐shaped PCL systems were also evaluated, and a significant solvent effect was observed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 175–182, 2006
Effect of vibration parameters of electromagnetic dynamic plastics injection molding machine on mechanical properties of polypropylene samples
Authors: Quan Wang , Qu Jin‐Ping , Liang He 
Published: July 2006

AbstractDynamic injection processing experiments have been carried out on polypropylene using the self‐made electromagnetic dynamic plastics injection molding machine, and the effects of the vibration force field on mechanical properties of molding samples are studied, namely, the influence of vibration frequency and vibration amplitude on the mechanical properties of samples are researched by using tensile testing, impact testing, differential scanning calorimeter (DSC) and scanning electronic micrograph (SEM) techniques. The results show that the tensile strength and impact strength are both enhanced and the melting point shifts toward the higher temperature, which facilitates the perfection of crystal. The best vibration parameters for processing polypropylene using electromagnetic dynamic plastics injection molding machine are that frequency is from 3 to 9 Hz and amplitude is from 0.1 to 0.4 mm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 972–976, 2006
Controlled release of bovine serum albumin using MPEG–PCL diblock copolymers as implantable protein carriers
Authors: Kim Moon Suk , Seo Kwang Su , Hyun Hoon , Khang Gilson , Cho Sun Hang , Lee Hai Bang 
Published: July 2006

AbstractMPEG–PCL diblock copolymers consisting of methoxy polyethylene glycol (MPEG) and poly(ϵ‐caprolactone) (PCL) as drug carriers were synthesized by ring‐opening polymerization. It is possible to control the balance between hydrophilic and hydrophobic by changing the MPEG and the ratio of ϵ‐CL to MPEG. Implantable wafers were easily fabricated by the direct compression method after physical mixing of diblock copolymers and bovine serum albumin–fluorescein isothiocyanate (BSA‐FITC) as a model protein drug. The BSA release from wafers prepared by MPEG–PCL diblock copolymers were higher than that from PCL with the physical blending of MPEG. The wafers prepared by a variety of MPEG–PCL diblock copolymers exhibited the controlled BSA release profiles with a dependence on MPEG–PCL diblock copolymer compositions. In addition, the changing of MPEG and PCL molecular weights within MPEG–PCL diblock copolymer controlled the initial burst of BSA. We confirmed that the diblock copolymers could be served as protein delivery carrier in implantable wafer form. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1561–1567, 2006
Modification and characterization of poly(ethylene‐co‐vinyl alcohol) by glycosidation reaction
Authors: Liu Binyuan , Xue Zhixin , Liu Lu , Zhang Li , Liu Fang 
Published: July 2006

AbstractPoly(ethylene‐co‐vinyl alcohol) was modified by the covalent bonding of a glucose ester via acetal formation of a surface hydroxyl group using acid as the catalyst. Grafted copolymers were characterized by 1H‐NMR, Fourier transform IR spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:227–232, 2006
Influence of moisture regain of aramid fibers on effects of atmospheric pressure plasma treatment on improving adhesion with epoxy
Authors: Liu L. , Jiang Q. , Zhu T. , Guo X. , Sun Y. , Guan Y. , Qiu Y. 
Published: July 2006

AbstractOne difference between a low‐pressure plasma treatment and an atmospheric pressure plasma treatment is that in the atmosphere, the substrate material may contain significant quantities of moisture, which could potentially influence the effects of the plasma treatment. To investigate how the existence of moisture affects atmospheric pressure plasma treatment, aramid fibers (Twaron 1000) with three different moisture regains (0.5, 4.5, and 5.5%) were treated by an atmospheric pressure plasma jet for 3 s at a gas flow rate of 8 L/min, a treatment head temperature of 100°C, and a power of 10 W. The scanning electron microscopy analysis showed no observable surface morphology change for the plasma treated samples. X‐ray photoelectron spectroscopy analysis showed the oxygen contents of the 0.5 and 4.5% moisture regain groups increased from that of the control, although the opposite was true for the 5.5% moisture regain group. The advancing contact angles of the treated fibers decreased about 8°–16° whereas their receding contact angles decreased about 17°–27°. The interfacial shear strengths of the treated fibers as measured using microbond pull‐out tests were more than doubled when the moisture regain was 4.5 or 5.5%, whereas it increased by 58% when the moisture regain was 0.5%. In addition, no significant difference in single fiber tensile strength was observed among the plasma treated samples and the control sample. Therefore, we concluded that moisture regain promoted the plasma treatment effect in the improvement of the adhesion property of aramid fibers to epoxy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 242–247, 2006
Effect of carbon blacks on relaxation phenomenon of chlorobutyl vulcanizates
Authors: Sridhar V. , Choudhary R. N. P. , Tripathy D. K. 
Published: July 2006

AbstractThe effect of the types of carbon black on the physicomechanical, dynamic mechanical, and dielectric relaxation spectra in chlorobutyl vulcanizates was studied. The primary relaxation (α transition, the glass transition) was studied by dynamic mechanical analysis as a function of temperature (−60 to +100°C) and by positron annihilation lifetime spectroscopy (−70 to +100°C). Irrespective of the type of carbon black that was used, all composites showed glass‐transition temperatures in the range of −29 to −33°C, which was explained on the basis of the relaxation dynamics of polyisobutylene chains in the vicinity of the fillers. The secondary relaxation (α* or β relaxation) was studied using dielectric relaxation spectra in the frequency range of 100–106 Hz. The nonlinear strain dependent dynamical parameters (Payne effect) were also evaluated at dynamic strain amplitudes of 0.07–5%. The nonlinearity in the tan δ and storage modulus was explained by the concept of filler–polymer interactions and the interaggregate attraction (filler networking). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1809–1820, 2006
Effect of fatty amine and perfluorocarbon as anti‐fouling agent on the catalyst activity and titanium oxidation state in slurry polymerization of ethylene
Authors: Mousavi Mojtaba , Hakim Shokoofeh , Nekoomanesh Mehdi 
Published: July 2006

AbstractIn this work, the effect of two antifouling materials on the activity of catalyst used to produce polyethylene in a 1‐L slurry reactor and on the titanium oxidation state of the catalyst was investigated. Armostat 300 with the formula alkyl C14‐C18 bis(2‐hydroxyethyl)amine is an antistatic agent that reduces static electricity of the polymer particles. It was found that within the concentration of 0.16–1.32 g/mmol Ti, Armostat 300 helps to increase the catalyst activity to 1.3–2 times. The variation of the titanium oxidation state of the catalyst in the presence of Armostat 300 at 80°C with Al/Ti molar ratio of 100 showed that Ti (III) species increased. The effect of Armostat 300 on Tm, % Xc, density, bulk density, and MFI of polymer was insignificant. In this work, Zonyl FSN‐100 with the formula Rf(CH2CH2O)xH, Rf = F(CF2CF2)y, y = 1–9, x = 1–26 was used as antifouling agent in copolymerization of ethylene with 1‐butene. It was found that Zonyl FSN‐100 at the concentration range of 5–20 ppm reduces the catalyst activity to 1.11–1.9 times. It was also shown that Ti (III) species in the presence of Zonyl FSN 100 decreased. This antifouling agent slightly decreased the properties of polymer including % Xc, density, and Mw. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 257–260, 2006