bluuebunny/crossref_metadata_2025_split huggingface dataset:
Loss and transformation products of the aromatic antioxidants in MDPE film under long‐term exposure to biotic and abiotic conditions
Authors: Haider Nadejzda , Karlsson Sigbritt 
Published: August 2002

AbstractThe loss of a primary phenolic antioxidant Irganox 1010 and of a secondary phosphite antioxidant Irgafos 168 from a medium density polyethylene film (MDPE) was investigated after exposure of the film for 4 years to different environments such as aqueous media at pH5 and 7, open air, and compost, with an exposure of exposition of 25°C. An ultrasonic extraction technique using chloroform as extraction solvent was applied to recover the residual antioxidants from the polymeric matrix, and this was followed by High‐Performance Liquid Chromatography (HPLC) with acetonitrile as mobile phase and a quantitative analysis at a wavelength of 280 nm of the extracted antioxidants. The amount of antioxidant lost varied remarkably depending on the testing medium. The fastest loss of antioxidant was found on exposure to open air and sunlight while the slowest loss was observed in compost. Thermo‐analytical measurements were made to characterize the residual thermo‐oxidative stability of MDPE film in terms of oxidation temperature and oxidation induction time, to provide a greater insight into the underlying mechanisms of ageing in the different environments. Analysis by Gas chromatography–Mass Spectrometry (GC‐MS) revealed that degradation of the polymeric matrix resulted in the formation of hydrocarbons and oxygen‐containing compounds such as alcohols, carboxylic acids, aldehydes, and esters. The transformation products of the antioxidants formed as result of processing or exposure to the tested media were also identified. The transformation of the phenoxy radical of the Irganox 1010 produced the ester, acid, dealkylated cinnamate, and quinone products, whereas Irgafos 168 yielded oxidation products and the phenolic hydrolysis byproduct 2,4‐di‐tert‐butylphenol. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 974–988, 2002
Synthesis and characterization of poly[(R, S)‐3‐hydroxybutyrate] telechelics and their use in the synthesis of poly(methyl methacrylate)‐b‐ poly(3‐hydroxybutyrate) block copolymers
Authors: Arslan Hülya , Hazer Baki̇ , Kowalczuk Marek 
Published: August 2002

AbstractPoly[(R,S)‐3‐hydroxybutyrate] oligomers containing dihyroxyl (PHB‐diol), dicarboxylic acid (PHB‐diacid) and hydroxyl‐carboxylic acid (a‐PHB) end functionalities were obtained by the anionic polymerization of β‐butyrolacton (β‐BL). Ring opening anionic polymerization of β‐BL was initiated by a complex of 18‐Crown‐6 with γ‐hydroxybutyric acid sodium salts (for PHB‐diol and a‐PHB) or succinic acid disodium salt (for PHB‐diacid). Dihydroxyl functionalization was formed by the termination of polymerization with bromo‐ethanol or bromo‐decanol while the others were done by protonation. Hydroxyl and/or carboxylic acid functionalized PHB oligomers with ceric salts were used to initiate the polymerization of methylmethacrylate (MMA). PHB‐b‐PMMA block copolymers obtained by this way were purified by fractional precipitation and characterized using 1H‐NMR and 13C‐NMR, gel permeation chromatography (GPC), and thermal analysis (DSC and TGA) techniques. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 965–973, 2002
In situ polyurethane/silica composite formation via a sol‐gel process
Authors: Park No‐Hyung , Lee Joon‐Woo , Suh Kyung‐Do 
Published: August 2002

AbstractPolyurethane acrylate anionomer (PUAA)/silica composite gels were prepared by the sol‐gel reaction of tetraethoxysilane (TEOS) and methacryloxypropyl trimethoxysilane (MPTS) incorporated to PUAA gels by using a swelling method. The formation and structure of composites were confirmed by FTIR, X‐ray diffraction, and SEM. As a result, we found that silica components in composites are located within the ionic domains of their gels and interacted with PUAA via hydrogen bonding. This drastically enhanced the mechanical properties of the composites. Mechanical properties are also improved by MPTS, because MPTS improves the dispersibility and adhesion of silica components in PUAA/silica composite gels. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2327–2334, 2002
Analysis of mixed mode polymerization systems. I. Generalized modeling approach
Authors: Giannakitsas Ioannis , Teymour Fouad 
Published: August 2002

AbstractMixed Mode Polymerization (MMP) is introduced and defined as any polymerization process that combines chainwise and stepwise mechanisms, which both contribute to the growth and structure modification of its polymer product. The large difference in activation energies of the growth steps of these two mechanisms provides great flexibility for polymer property control. A large variety of possible combinations including these mechanisms can be designed, which leads to a diversity of processes that require the development of a unified treatment technique. Building on the well‐established theories and modeling frameworks available for free‐radical polymerization and polycondensation, a generalized approach for modeling MMP is developed. Example applications of the technology are discussed and a case study is analyzed to illustrate the applicability of the generalized modeling approach. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 571–594, 2002
[Poly(ethylene terephthalate) ionomer]/silicate hybrid materials via polymer–in situ sol‐gel reactions
Authors: Lambert Alexander A. , Mauritz Kenneth A. , Schiraldi David A. 
Published: August 2002

AbstractA scheme was developed for producing poly(ethylene terephthalate (PET) ionomer)/silicate hybrid materials via polymer–in situ sol‐gel reactions for tetraethylorthosilicate (TEOS) using different solvents. Scanning electron microscopy/EDAX studies revealed that silicate structures existed deep within PET ionomer films that were melt pressed from silicate‐incorporated resin pellets. 29Si solid‐state NMR spectroscopy revealed considerable Si—O—Si bond formation, but also a significant fraction of SiOH groups. 23Na solid‐state NMR spectra suggested the presence of ionic aggregates within the unfilled PET ionomer, and that these aggregates do not suffer major structural rearrangements by silicate incorporation. For an ionomer treated with TEOS using MeCl2, Na+ ions are less associated with each other than in the unfilled control, suggesting silicate intrusion between PET–SO Na+ ion pair associations. The ionomer treated with TEOS + tetrachloroethane had more poorly formed ionic aggregates, which illustrates the influence of solvent type on ionic aggregation. First‐scan DSC thermograms for the ionomers demonstrate an increase in crystallinity after the incorporation of silicates, but solvent‐induced crystallization also appears to be operative. Second‐scan DSC thermograms also suggest that the addition of silicate particles is not the only factor implicated in recrystallization, and that solvent type is important even in second‐scan behavior. Silicate incorporation does not profoundly affect the second scan Tg vs. solvent type, i.e., chain mobility in the amorphous regions is not severely restricted by silicate incorporation. Recrystallization and melting in these hybrids appears to be due to an interplay between a solvent‐induced crystallization that strongly depends on solvent type and interactions between PET chains and in situ‐grown, sol‐gel‐derived silicate particles. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1749–1761, 2002; DOI 10.1002/app.10586
Synthesis and investigation of the properties of poly(phenyl‐α‐naphthylsilylene)–dimethylsilylene copolymers
Authors: Mukbaniani O. V. , Tatrishvili T. N. , Karchkhadze M. G. 
Published: August 2002

AbstractA Wurtz‐type reductive coupling reaction of dichlorophenyl‐α‐naphthylsilane was carried out in a mixture of toluene and o‐xylene in the presence of sodium and a catalytic amount of mercury; α,ω‐dichlorophenyl‐α‐naphthylsilylenes of various degrees of polymerization were obtained. Through the hydrolysis of α,ω‐dichlorophenyl‐α‐naphthylsilylenes, corresponding dihydroxy compounds were obtained. The heterofunctional polycondensation of α,ω‐dihydroxyphenyl‐α‐naphthylsilylenes with α,ω‐dichlorodimethylsilylenes was performed both without amines and in the presence of amines. Heterofunctional polycondensation without amines did not proceed with the formation of high molecular weight compounds because the cleavage of both  SiSi and SiOSi bonds took place during condensation. In the presence of amines, polysilylene–silylene copolymers were obtained. The synthesized copolymers were investigated with gel permeation chromatography, differential scanning calorimetry, roentgenography, and thermogravimetry. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1047–1056, 2002
Synthesis and light‐emitting properties of new poly(p‐phenylenevinylene) derivatives containing oxadiazole moiety
Authors: Wang Shu , Hua Wenting , Chen Xiaohong , Hou Yanbing 
Published: August 2002

AbstractTwo new poly(p‐phenylenevinylene) (PPV) derivatives containing oxadiazole moiety (OXA‐PPV1 and OXA‐PPV2) were synthesized by the Wittig condensation polymerization reaction. Their thermal and light‐emitting properties were investigated. The single‐ and triple‐layer electroluminescent (EL) devices with configurations of ITO/polymer/Al and ITO/polymer/OXD‐7/Alq3/Al were fabricated. They exhibited blue emission at 470 nm for OXA‐PPV1 and green emission at 560 nm for OXA‐PPV2. The turn‐on voltages of triple‐layer device were 11 V for OXA‐PPV1 and 8 V for OXA‐PPV2. The triple‐layer EL devices showed much better performance than did the single‐layer devices. The spectra indicated energy transfer occurred from segments of side chain to polymer backbone. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 422–428, 2002
Polytetrahydrofuran amphiphilic networks. III. Synthesis and characterization of pH‐sensitive poly(methacrylic acid)‐l‐polytetrahydrofuran networks
Authors: Guan Ying , Jiang Weiwen , Zhang Wenchuan , Wan Guoxiang , Peng Yuxing 
Published: August 2002

AbstractA series of pH‐sensitive amphiphilic poly(methacrylic acid)‐l‐polytetrahydrofuran (PMAA‐l‐PTHF) networks were prepared by free radical copolymerization of hydrophobic telechelic polytetrahydrofuran diacrylates (PTHFDA) with hydrophilic methacrylic acid(MAA). Network composition was characterized. The networks are amphiphilic, namely, that swell both in organic solvents and in water. The swelling of the networks in organic solvents or in water is composition dependent. Swelling dynamics of networks indicates a non‐Fickian process in cyclohexane as well as in water. According to swelling experiments, four solubility parameters of PMAA‐l‐PTHF networks were obtained, which correspond to the hydrophilic and hydrophobic segments, and the interaction between these two segments and solvents. The networks are pH sensitive in aqueous media. These results indicate that PMAA‐l‐PTHF networks exhibit not only the properties of PMAA and PTHF segments but also the combined properties of them. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 351–357, 2002
Metal‐solvating and self‐association of amphiphilic polyamides containing poly(oxyethylene) blocks
Authors: Lin J. J. , Cheng I. J. 
Published: August 2002

AbstractAn amphiphilic poly(ether amide) consisting of hydrophilic poly(oxyethylene) amide blocks was prepared from the copolymerization of sebacic acid and two poly(oxyalkylene) diamines including a poly(oxyethylene) diamine (POE‐amine at 2000 Mw) and a poly(oxypropylene) diamine (POP‐amine at 230 Mw). The copolymer was estimated to have an average molecular weight of 15,000 Mw (GPC) or approximately three hydrophilic POE segments per strain. The presence of POE segments rendered polymer hydrophilicity and complexing ability for Li+, K+, Ca+2, Ni+2, Pd+2, and Cu+2 salts. In particular, lithium perchlorate affected the copolymer to the greatest extent in enhancing electrostatic dissipation or reducing surface resistivity as low as 105.0 Ω/sq (cross‐sectional area) at 1/180 Li+/EO from 107.2 Ω/sq (without metal ion). In such a metal complexation, the copolymer showed a new POE segmental crystalline phase at a melting temperature between −10.4 and −14°C, accompanied with the metal‐free original phase of −31°C. In static toluene/water, the metal ions had no effect on the copolymer surfactancy in lowering the interfacial tension, reaching 4.4 dyn/cm at a critical micelle concentration (cmc) of 0.01 wt %. When mixing toluene and water, the lithium or nickel ions were found to be detrimental to the emulsifying process. Without the metal ion, fine droplets at average sizes of 4.5–5.0 μm were observed in the copolymer/ toluene/water emulsification. These amphiphilic behaviors of the POE‐segmented polyamide with or without metal ions were explained by the competing noncovalent bonding interactions among POE/metal ion/water. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 612–621, 2002
In vitro release modulation of hemoglobin from a ternary polymeric delivery vehicle
Authors: Bajpai A. K. , Bhanu Smitha 
Published: August 2002

AbstractThe release of hemoglobin from hydrogel matrices of polyethylene glycol (PEG), polyvinyl alcohol (PVA), and crosslinked polyacrylamide (PAM) was investigated in phosphate‐buffered saline (PBS, pH 7.4) as a release medium. The hemoglobin was loaded onto hyrogels by swelling them in hemoglobin solution and the effect of composition of the hydrogel on the amount of hemoglobin loaded was observed. The effects of experimental parameters such as varying concentrations of PEG, PVA, PAM, and crosslinking agent in the feed mixture, pH of the release medium, and the presence of salts were investigated on the release dynamics of the hemoglobin. The release results were analyzed on the basis of the kinetic data, and the kinetic parameters such as the diffusional exponent (n) and diffusion constant (D) were evaluated. From the kinetic parameters data an attempt was made to explore the nature of the mechanism of the hemoglobin release process. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 104–113, 2002
Thermal decomposition characteristics of poly[diethyl‐2‐(methacryloyloxy)ethyl phosphate] using thermogravimetric analysis/mass spectrometry
Authors: Perng L. H. , Tsai C. J. , Ling Y. C. , Wang S. D. , Hsu C. Y. 
Published: August 2002

AbstractThe thermal decomposition of poly[diethyl 2‐(methacryloyloxy)ethyl phosphate] (PDMP) by free‐radical polymerization was studied by the combination of pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS) with thermogravimetric analysis/mass spectrometry (TG/MS), in which the former identified directly the compositions of the evolved gases and the latter could further obtain real‐time evolution curves of pyrolysates. A decomposition of PDMP was a two‐stage process: The dominant mechanism of the first stage was initialized by hydrolysis at the phosphate ester linkage to evolve hydroxyethyl methacrylate (HEMA), triethylphosphate, and ethanol as major products; then, subsequently, the dominant mechanism of the second stage was a main‐chain random scission to form acetaldehyde and water as major products along with carbonization of about 24% char yield of a solid residue at 600°C. Therefore, the reaction of phosphate groups into the backbone of polymeric materials could provide better flame retardancy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 821–830, 2002
Electrochemical copolymerization of aniline and anilinesulfonic acids in FSO3H/acetonitrile solution
Authors: Şahin Yücel , Pekmez Kadir , Yildiz Attila 
Published: August 2002

AbstractThe effects of 2‐aminobenzenesulfonic acid (orthanilic acid), 3‐aminobenzenesulfonic acid (metanilic acid), and 4‐aminobenzenesulfonic acid (sulfanilic acid) on the electropreparation and properties of polyaniline (PANI) were investigated in acetonitrile containing 200 mM fluorosulfonic acid. The cyclic voltammetric studies of the products showed characteristics similar to those of conventional PANI in neutral solution, but there was a significant difference between the electrochemical behavior of the polymer films in basic solution. The sulfur‐to‐nitrogen ratios were found to be about 0.50, which indicated that copolymers were formed. The copolymers were soluble in a basic aqueous solution and in 1‐methyl‐2‐pyrrolidinone and dimethyl sulfoxide solvents. The dry electrical conductivity values of the copolymers were measured. The structure and properties of these conducting copolymers in acetonitrile were elucidated with cyclic voltammetry, Fourier transform infrared spectroscopy, and ultraviolet–visible absorption spectroscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1227–1235, 2002
Tensile deformation and fracture mechanism of highly filled high‐density polyethylene/Al(OH)3 composites
Authors: Yang Jinhai , Zhang Yong , Zhang Yinxi 
Published: August 2002

AbstractThe effect of the silicone oil content on the tensile properties and micromechanical deformation of high‐density polyethylene/Al(OH)3 composites was studied. With an increase in the silicone oil content, the elongation at break and notched Izod impact strength of the composites increased, and the local debonding deformation gradually transformed into homogeneous debonding deformation. A model characterizing the micromechanical deformation process was examined. The increase in the silicone oil content decreased the interaction between the filler particles and the high‐density polyethylene matrix and increased the extension speed of the debonded region, which led to the changes in the tensile properties and micromechanical deformation. A good explanation for the tensile properties and micromechanical deformation was obtained through the model. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1207–1218, 2002
Studies on the mesomorphic properties of ferrocenylene‐based organophosphorous liquid‐crystalline polymers containing phenyl and biphenyl pendant units
Authors: Senthil S. , Kannan P. 
Published: August 2002

AbstractThe synthesis, mesomorphic character, and effect of spacers in ferrocene‐containing main‐chain liquid‐crystalline polymers are reported in this article. Two different monomers containing ferrocene and phenyl/biphenyl phosphate groups possessing even numbers of spacers from 2 to 10 were prepared and polymerized by polycondensation at room temperature. All the polymers gave birefringent melt except one. The identification of the mesophase was transparent with an increase in spacers. The effect of substitution in the side chain with regard to bulkiness and spacers were studied with thermogravimetric analysis and differential scanning calorimetry. The results reveal that the thermal stability of the polymers increased with the increasing bulkiness of the side chain and decreased with increasing spacer length. The incorporation of the phosphorous moiety also had a considerable effect on the glass‐transition temperature. Char yield of the polymer decreased with increasing methylene chain length, and it did not vary much with the size of the pendent groups. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 831–841, 2002
Syntheses of an aromatic nitrile ether diamine and the bismaleimide bearing the diamine and the properties of their copolymers with 4,4′‐bismaleimidodiphenylmethane (BMDPM)
Authors: Fang Qiang , Ding Xuemei , Wu Xiongying , Jiang Luxia 
Published: August 2002

AbstractA new chain‐extension modifier for bismaleimide (BMI), 2,6‐di‐(4‐aminophenoxy)benzonitrile (DAPB), was synthesized through nucleophilic substitution of 2,6‐dichlorobezonitrile by 4‐aminophenol using anhydrous sodium carbonate as an acid acceptor, toluene as a dehydrating agent, and N,N′‐dimethylacetamide (DMAC) as a dipolar aprotic solvent. Based on the diamine, another modifier for bismaleimide, 2,6‐bis(4‐maleimidophenoxy)benzonitrile (BMPB), was also synthesized, first by the reaction of DAPB with maleic anhydride and then by dehydration. DAPB and BMPB were used to modify a popular commercial BMI, 4,4′‐bismaleimidodiphenylmethane (BMDPM), for improving the shear strength of the resin. The results showed that the shear strength of the DAPB‐modified BMDPM resin was superior to that of either neat BMDPM or the 4,4′‐diaminodiphenylmethane (DADPM)‐modified BMDPM (a commercial modified BMDPM resin system). In addition, the heat resistance of the cured DAPB‐modified BMDPM resin was higher than that of the cured DADPM‐modified BMDPM resin. The excellent properties were also found in the BMPB‐modified BMDPM resin. It was found that the BMPB‐modified BMDPM resin was superior to neat BMDPM in both shear strength and heat resistance. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1317–1327, 2002
Viscosity–molecular weight relationship for aminopropyl‐terminated poly(dimethylsiloxane)
Authors: Wu Yongzhong , Feng Shengyu 
Published: August 2002

AbstractAminopropyl‐terminated poly(dimethylsiloxane) (ATPS) with different molecular weights was prepared by base‐catalyzed equilibration of octamethylcyclotetrasiloxane and 1,3‐bis(3‐aminopropyl)‐1,1,3,3‐tetramethyldisiloxane with different ratios. Their number‐average molecular weights (Mn) were determined by end–group analysis, and intrinsic viscosity ([η]) in toluene was measured with a Ubbelohde viscometer. A relationship between Mn and [η] was obtained for ATPS. For 1.0 × 104 < Mn < 6.0 × 104, it was in accord with [η]toluene,25°C = 5.26 × 10−2 Mn0.587. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 975–978, 2001
Gas–liquid chromatographic study of polystyrene–n‐alkane interactions
Authors: Naik Huchchuraya G. , Aminabhavi Tejraj M. 
Published: August 2002

AbstractGas–liquid chromatography is used to study the thermodynamic interactions between polystyrene and n‐alkanes (C6–C10). Polystyrene is used as a stationary phase with n‐alkanes as the probe molecules. Retention times and specific retention volumes are measured over the temperature interval of 60 to 170°C. Partial molar free energy of mixing, polymer–solvent interaction parameter, glass‐transition temperature, and solubility parameter of polystyrene at infinite dilution are calculated. Experimental results are discussed in terms of the theoretical calculations and size of the probe molecules. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1291–1298, 2001
Synthesis of novel poly(amide‐imide)s containing trimellitylimido‐DL/L‐alanine moieties via direct polycondensation
Authors: Mallakpour Shadpour E. , Hajipour Abdol‐Reza , Habibi Sakineh 
Published: August 2002

AbstractN‐Trimellitylimido‐DL and L‐alanine (3) were prepared from the reaction of trimellitic anhydride (1) with DL and L‐alanine (2) in N,N‐dimethyl formamide (DMF) solution at refluxing temperature. The direct polycondensation reaction of the monomers imide‐diacid (3) with 4,4′‐diaminodiphenylsulfone (4a), 4,4′‐diaminodiphenylmethane (4b), 1,4‐phenylenediamine (4c), 1,3‐phenylenediamine (4d), 2,4‐diaminotoluene (4e), and 4,4′‐diaminodiphenylether (4f) was carried out in a medium consisting of triphenyl phosphite, N‐methyl‐2‐pyrolidone (NMP), pyridine, and calcium chloride. The resulting poly(amide‐imide)s PAIs, with inherent viscosities 0.32–0.66 dL/g, were obtained in high yield. All of the above‐mentioned compounds were fully characterized by IR, elemental analyses, and specific rotation. Some structural characterization and physical properties of these new optically active PAIs are reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1312–1318, 2001