bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and thermal behavior of thermotropic terpolymers based on 8‐(3‐hydroxyphenyl)octanoic acid, 2,6‐naphthalenedicarboxylic acid, and substituted hydroquinones
Authors: Vijayanathan Veena , Prasad V. S. , Pillai C. K. S. 
Published: October 2004

AbstractAromatic–aliphatic thermotropic liquid crystalline terpolyesters derived from 2,6‐naphthalenedicarboxylic acid, hydroquinones, and 8‐(3‐hydroxyphenyl)octanoic acid (HPOA), a monomer with built‐in kink and flexible moieties, were prepared by a melt polycondensation reaction. These polymers were characterized for their thermotropic liquid crystalline properties. The effect of variation in the composition of the polyester on the liquid crystalline behavior and thermal properties was also studied. Increasing the content of kinked units increased the amount of structural irregularity and decreased the isotropization temperature. The Tm and thermal stability of the polyesters were found to decrease with increase in the HPOA content. The formation of the liquid crystalline phase was not prevented by the introduction of up to 40 mol % of HPOA in the copolyester. The effect of substituents on the thermal properties of the terpolyesters was also studied. Introduction of a phenyl substituent on the hydroquinone ring was found to lower the transition temperature compared to substituents such as methyl or methoxy. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1021–1029;2001
Particle nucleation mechanism for the emulsion polymerization of styrene with a novel polyester emulsifier
Authors: Chang Yih‐Her , Lee Yu‐Der , Karlsson Ola J. , Sundberg Donald C. 
Published: October 2004

AbstractThe particle nucleation mechanism in emulsion polymerization of styrene with a novel polyester emulsifier, 5‐sulfoisophthalic acid dimethyl ester sodium salt‐modified tetracarboxylic acid‐terminated polyester (SMTAPE), was investigated. The consumption of SMTAPE micelles was monitored by the measurement of surface tension during the emulsion polymerization. Kinetic studies and emulsifier consumption clearly showed that a continuous nucleation mechanism without Smith–Ewart interval II was characteristic of this system. It was attributed to the high concentration of SMTAPE emulsifier in the polymerization, which led to a large surface area and a vast number of micelles around 10 nm in size that served as the major locus of particle nucleation. A broad particle size distribution was observed throughout the reaction, and the nucleation period lasted well into the reaction until the disappearance of the micelles or the disappearance of monomer droplets. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1061–1070, 2001
Characterization of cellulose aldehyde using Fourier transform infrared spectroscopy
Authors: Fan Q. G. , Lewis D. M. , Tapley K. N. 
Published: October 2004

AbstractFourier transform infrared spectroscopy has been used to study cellulose aldehyde groups in bleached cotton, unbleached cotton, and in periodate oxidized cotton. Second derivative spectroscopy could reproducibly identify aldehyde bonds in oxidized cotton only if the samples were predried at 110°C for 24 h; the aldehyde band appeared at 1732–1734 cm−1. Diffuse reflectance spectroscopy in the Environmental Chamber readily detected the above aldehyde absorbances at temperatures above 100°C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1195–1202, 2001
Synthesis and adsorption properties of magnetic resin microbeads with amine and mercaptan as chelating groups
Authors: Zhang Chaocan , Li Xi , Pang Jinxing 
Published: October 2004

AbstractThree magnetic chelating resins containing amino and mercapto groups were prepared by the suspended condensation polymerization of 2‐chloroethoxymethyl thiirane with diamines. The magnetic resins were microbeads whose diameter was in the range of 10 to 45 μm. The structure of the resins was characterized by XPS, IR, and elemental analysis. Their adsorption properties for Hg(II), Au(III), Pd(II), Pt(IV), Ag(I), Cu(II), Zn(II), and Pb(II) were investigated. The experimental results show the magnetic resins have high affinity for Hg(II) and noble metal ions. In the competitive adsorption, the resins predominantly adsorbed Hg(II) or Pd(II) in the coexistence of Cu(II), Zn(II), and Mg(II). Desorption of Pd(II) loaded on the resins was studied by using 2M hydrochloric acid solution containing 1% thiourea as desorbent. A high desorption ratio (up to 96.5%) was observed, and repeated adsorption/desorption operations showed the probability of repeated use of the magnetic resins. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1587–1592, 2001
Study of adsorption of nonionic surfactants at the liquid–solid interface by FTIR/CIR
Authors: Mansur Claudia R. E. , Benzi Márcia R. , Lucas Elizabete F. 
Published: October 2004

AbstractFourier transform infrared spectroscopy (FTIR), using the attenuated total reflectance (ATR) method, can be used to characterize the interface of a system. We investigated the adsorption at the liquid–solid interface of nonionic surfactant aqueous solutions with or without a hydrotropic agent. We studied monofunctional diblock copolymers of poly(ethylene oxide‐propylene oxide) (PEO–PPO) as nonionic surfactants and sodium p‐toluenesulfonate (NaPTS) as hydrotropic agent. The samples were analyzed by FTIR technique using the circular internal reflectance (CIR) accessory, which confirmed that the hydrotrope shifts the surfactant from the liquid–solid interface. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1668–1676, 2001
Applications of epoxidized and hydroxy‐fluoroester pendent secondary high‐molecular‐weight guayule rubber in coatings
Authors: Gupta Sandhya , Mendon Sharathkumar K. , Thames Shelby F. 
Published: October 2004

AbstractThe epoxidation of secondary high‐molecular‐weight guayule rubber to yield epoxidized guayule rubber (EGR) and the subsequent opening of the oxirane rings by fluoroacids to yield fluorinated guayule rubber (FGR) were reported in an earlier article.1 The oxirane and hydroxyl groups that occur in EGR and FGR, respectively, enable these derivatives to be integrated into the binder system of coatings. The coating industry has long been interested in nontoxic multifunctional crosslinking agents that do not emit volatile organic compounds (VOCs). Ring‐opening reactions of epoxides and reactions between hydroxyl and isocyanate groups are prime examples of crosslinking that do not emit VOCs. This study was conducted to ascertain the viability of guayule rubber derivatives that contain epoxide and hydroxyl groups as crosslinking agents in solvent‐based coatings and powder coatings. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1718–1724, 2001
Block copolymer formation from the melt reaction between polycarbonate and poly(ethylene‐co‐butylene) diol
Authors: Lee Sukmin , Park Jun Sang , Lee Hosull 
Published: October 2004

AbstractThe block copolymer formation from the exchange reaction between polycarbonate (PC) and poly(ethylene‐co‐butylene) diol (POH) occurring during melt mixing was studied. The exchange reaction proceeded by the attack of active chain ends of hydroxyl‐terminated POH on the inner carbonate groups of PC. The reaction was accelerated in basic condition in the presence of a hindered amine. The formation of block copolymer was confirmed by 1H–NMR analysis. The proceeding of the exchange reaction was analyzed with UV spectrometry by measuring the absorbance at 285 nm of the less‐reactive phenolic end group of PC oligomers produced. The reaction was terminated when the hydroxyl end groups of POH were completely consumed. It was found from the analyses by GPC and DSC that the exchange reaction between PC and POH takes place rather uniformly by random scission of the chain. The block copolymer obtained here will be employed as a compatibilizer of PC/polyolefin blends in a future study. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1725–1732, 2001
Characterization of grafting in the emulsion polymerization of vinyl acetate using poly(vinyl alcohol) as stabilizer
Authors: Egret Hélène , Dimonie Victoria L. , Sudol E. David , Klein Andrew , El‐Aasser Mohamed S. 
Published: October 2004

AbstractEmulsion polymerizations of vinyl acetate (VAc) with polyvinyl alcohol (PVA) as emulsifier were carried out by both batch and semicontinuous processes. The extent of grafting of vinyl acetate onto the PVA chains was investigated by a new method for separating the various polymer fractions in high solids content latexes. The quantification was carried out by a three‐step separation and selective solubilization of the PVAc latexes. After the separation, the water‐soluble PVA and the solvent‐soluble PVAc components were characterized by gel permeation chromatography and 13C–NMR, from which the accuracy of this method was verified. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1739–1747, 2001
Achieving compatibility in blends of low‐density polyethylene/polyamide‐6 with addition of ethylene vinyl acetate
Authors: Taşdemi̇r Münir , Yildirim Hüseyin 
Published: October 2004

AbstractPolymer alloys and blends, whose major advantage is the potential of achieving a range of physical and mechanical properties, have continued to be a subject of interest over recent years. Addition of a block or graft copolymer, with chemically similar segments to those involved in the polymer blend considered, led to a variety of desirable properties. The copolymer added to the blend functioned to promote a homogeneous dispersion of the constituent phases and to enhance their mutual adhesion. Such agents that enable better dispersion in polymer blends are known as compatibilizers. In this study an attempt has been made to improve the compatibility in a polymer blend composed of two normally incompatible constituents, LDPE and PA6, by addition of a compatibilizer. The compatibilizer agent, ethylene vinyl acetate (EVA), was added to the polymer blend in ratios of 1, 5, and 10% by using a twin‐screw extruder. The effect of EVA on the crystallization of the polymer constituents was observed through DSC examinations. Furthermore, the control sample and all three blends of LDPE/PA6/EVA were subjected to examinations to obtain their yield and tensile strengths, elasticity modulus, percentage elongation, izod impact strength, hardness, and melt flow index. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1748–1754, 2001
Elastic polyaniline with EPDM and dodecylbenzenesulfonic acid as plasticizers
Authors: Faez Roselena , De Paoli Marco‐A 
Published: October 2004

AbstractElastomeric polyaniline was prepared by being mixed with ethylene–propylene–diene (EPDM) rubber in low concentrations (10, 20, or 30 wt %). The mixture was made in an internal mixer coupled to a torque rheometer. The polyaniline was doped with dodecylbenzenesulfonic acid (DBSA) via reactive processing during the mixing. When the EPDM rubber was added to the polyaniline and DBSA, the doping reaction was not interrupted, as demonstrated by an increase in the torque values. We chose the relative DBSA and EPDM concentrations to obtain the highest conductivities (10−1 to 10−3 S cm−1) and the best mechanical properties. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1768–1775, 2001
Dynamic properties of an organic hybrid of chlorinated polyethylene and hindered phenol compound
Authors: Wu Chifei , Otani Yoshio , Namiki Norikazu , Emi Hitoshi , Nitta Koh‐Hei , Kubota Saburo 
Published: October 2004

AbstractThe dynamic mechanical properties of hybrids of chlorinated polyethylene (CPE) and 3,9‐bis[1,1‐dimethyl‐2{β‐(3‐tert‐butyl‐4‐hydroxy‐5‐methylphenyl)propionyloxy}ethyl]‐2,4,8,10‐tetraoxaspiro[5,5]‐undecane (AO‐80) were investigated. The CPE/AO‐80 hybrids showed a novel relaxation in addition to the glass transition of CPE. The novel relaxation is attributed to the dissociation of intermolecular hydrogen bonds within the AO‐80–rich domain. The Payne effect, that is, the decrease of the storage modulus E′ with increasing strain amplitude and the appearance of a loss modulus E″ maximum at a strain of 0.6%, was observed for the CPE/AO‐80 hybrids. This result demonstrates that the AO‐80–rich domains within matrix polymer CPE form a network. The Payne effect is considered to be attributed to the mechanical disruption of segment–segment contacts at a sufficiently great strain. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1788–1793, 2001
Toughening of epoxy resin by functional‐terminated polyurethanes and/or semicrystalline polymer powders
Authors: Wang Huei‐Hsiung , Chen Jung‐Chieh 
Published: October 2004

AbstractHydroxyl‐, amine‐, and anhydride‐terminated polyurethane (PU) prepolymers, which were synthesized from polyether [poly(tetramethylene glycol)] diol, 4,4′‐diphenylmethane diisocyanate, and a coupling agent, bisphenol‐A (Bis‐A), 4,4′‐diaminodiphenyl sulphone (DDS), or benzophenonetetracarboxylic dianhydride, were used to modify the toughness of Bis‐A diglycidyl ether epoxy resin cured with DDS. Besides the crystalline polymers, poly(butylene terephthalate) (PBT) and poly(hexamethylene adipamide) (nylon 6,6), with particle sizes under 40 μm were employed to further enhance the toughness of PU‐modified epoxy at a low particle content. As shown by the experimental results, the modified resin displayed a significant improvement in fracture energy and also its interfacial shear strength with polyaramid fiber. The hydroxyl‐terminated PU was the most effective among the three prepolymers. The toughening mechanism is discussed based on the morphological and the dynamic mechanical behavior of the modified epoxy resin. Fractography of the specimen observed by the scanning electron microscopy revealed that the modified resin had a two‐phase structure. The fracture properties of PBT‐particle‐filled epoxy were better than those of nylon 6,6‐particle‐filled epoxy. Nevertheless, the toughening effect of these crystalline polymer particles was much less efficient than that of PU modification. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2903–2912, 2001
Development of formulations based on acrylate monomers for optical cable applications
Authors: Perera M. C. Senake 
Published: October 2004

AbstractMethyl methacrylate and 2‐ethyl hexyl acrylate were copolymerized in the presence of different crosslinkers with free‐radical initiation. The double‐bond conversion was monitored with in situ Fourier transform near‐infrared spectroscopic techniques. Dynamic mechanical properties of the resultant polymers were measured, and the curves were interpreted on the basis of the heterogeneity and flexibility of the samples. The optical properties of the cables made out of these systems were measured with transmission spectra. The effect of the addition of additives on the optical properties was demonstrated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3001–3012, 2001
In situ analysis of volatiles obtained from the catalytic cracking of polyethylene
Authors: Hesse Nathan D. , Lin Rong , Bonnet Edouard , Cooper Jesse , White Robert L. 
Published: October 2004

AbstractThe effects of the solid‐acid‐catalyst pore size and acidity on polyethylene catalytic cracking were examined with a comparison of the temperature‐dependent volatile‐product‐slate changes when the polymer was cracked with HZSM‐5 and HY zeolites and the protonated form of MCM‐41. Volatile‐product distributions depended on the catalyst acidity and pore size. With HZSM‐5, paraffins were detected initially, and olefins were produced at somewhat higher temperatures. Aromatics were formed at temperatures 30–40°C higher than those required for olefin production. Small olefins (C3–C5) were the most abundant products when HZSM‐5 and MCM‐41 catalysts were employed for cracking polyethylene. In contrast, cracking with HY produced primarily paraffin volatile products (C4–C8). HY pores were large enough and the acid sites were strong enough to promote disproportionation reactions, which led to the formation of volatile paraffins. Compared with the other catalysts, HZSM‐5 with its smaller pores inhibited residue formation and facilitated the production of small alkyl aromatics. Volatile‐product variations could be rationalized by a consideration of the combined effects of catalyst acidity and pore size on carbenium ion reaction pathways. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3118–3125, 2001
Synthesis of novel azo‐containing polyureas derived from 4‐[4′‐(2‐hydroxy‐1‐naphthylazo)phenyl]‐1,2,4‐triazolidine‐3,5‐dione
Authors: Mallakpour Shadpour E. , Nasr‐Isfahani Hossein 
Published: October 2004

Abstract4‐[4′‐(2‐Hydroxy‐1‐naphthylazo)phenyl]‐1,2,4‐triazolidine‐3,5‐dione (HNAPTD) (1) has been reacted with excess amount of n‐propylisocyanate in DMF (N,N‐dimethylformamide) solution at room temperature. The reaction proceeded with high yield, and involved reaction of both NH of the urazole group. The resulting bis‐urea derivative 2 was characterized by IR, 1H‐NMR, elemental analysis, UV‐Vis spectra, and it was finally used as a model compound for the polymerization reaction. Solution polycondensation reactions of monomer 1 with Hexamethylene diisocyanate (HMDI) and isophorone diisocyanate (IPDI) were performed in DMF in the presence of pyridine as a catalyst and lead to the formation of novel aliphatic azo‐containing polyurea dyes, which are soluble in polar solvents. The polymerization reaction with tolylene‐2,4‐diisocyanate (TDI) gave novel aromatic polyurea dye, which is insoluble in most organic solvents. These novel polyureas have inherent viscosities in a range of 0.15–0.22 g dL−1 in DMF at 25°C. Some structural characterization and physical properties of these novel polymers are reported. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3177–3183, 2001
Recycling of EPDM waste. II. Replacement of virgin rubber by ground EPDM vulcanizate in EPDM/PP thermoplastic elastomeric composition
Authors: Jacob Ceni , De P. P. , Bhowmick A. K. , De S. K. 
Published: October 2004

AbstractVirgin ethylene propylene diene monomer (EPDM) rubber in a thermoplastic elastomeric blend of polypropylene (PP) and EPDM rubber was substituted by ground EPDM vulcanizate of known composition, after which the mechanical properties of the raw EPDM/waste EPDM/PP blends were determined. The ratio of the rubber content in the waste EPDM (r‐W‐EPDM) to the raw EPDM (R‐EPDM) in the blends was varied from 0 : 100 to 45 : 55. Attempts to replace higher amounts (>45%) of R‐EPDM by W‐EPDM failed because of processing difficulty. Although a drop in mechanical properties of the blends was observed at lower loadings of W‐EPDM, the properties showed improvement at intermediate W‐EPDM loadings. The R‐EPDM/W–EPDM/PP blends were found to be reprocessable. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3304–3312, 2001
Mechanical properties and morphology of the modified HDPE/starch reactive blend
Authors: Jang Byung Chul , Huh Soo Young , Jang Jeong Gyu , Bae Young Chan 
Published: October 2004

AbstractWe investigated the effect of reactive blending on the mechanical properties and morphology of high‐density polyethylene (HDPE)/plasticized starch blends. HDPE was chemically modified to enhance the compatibility with the plasticized starch. The modified HDPE, HDPE‐g‐glycidyl methacrylate (GMA), was synthesized by melt reaction of HDPE in the presence of dicumyl peroxide (DCP). A finer dispersion of starch in the HDPE matrix was achieved compared to that in the unmodified HDPE. The amount of GMA groups in the modified HDPE enhanced the miscibility of HDPE/starch blends. We also observed that the amount of glycerin improves the mechanical properties of blends. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3313–3320, 2001
Imaging of conductive filler networks in heterogeneous materials by scanning Kelvin microscopy
Authors: Prasse Torsten , Ivankov Andrei , Sandler Jan , Schulte Karl , Bauhofer Wolfgang 
Published: October 2004

AbstractThis article reports a novel application of scanning Kelvin microscopy for exclusively revealing the distribution of a percolated conductive filler network in heterogeneous materials. The materials under investigation are carbon black and carbon nanotube‐filled epoxies with a highly inhomogeneous conductivity distribution due to their fabrication. The Kelvin method is demonstrated to be especially suitable for resolving the resistive particle network in these kinds of composite materials with sample resistance levels in the megaohm range. Transmission optical microscopy reveals matches between the scanning Kelvin images and the sample morphologies, whereas the percolating backbone cannot be distinguished in the optical micrographs. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3381–3386, 2001
Preparation and simulation of graded‐index polymer rods by interfacial‐gel polymerization
Authors: Chu Jiurong , Xu Chuanxiang , Wen Xuming , Wang Shoutai 
Published: October 2004

AbstractA graded‐index (GI) polymer rod was prepared by interfacial‐gel polymerization, in which polymerization was performed in a PMMA tube and bromobenzene (BB) was used as a higher refractive index molecules. By using the new technology, a GI polymer rod without any defect of void or bubble was made. A detailed mechanism and simulation of graded‐index formation were given according to the Vrentas‐Duda free volume theory. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3387–3390, 2001
Formation of a DNA/N‐dodecylated chitosan complex and salt‐induced gene delivery
Authors: Liu Wen Guang , De Yao Kang , Liu Qing Gang 
Published: October 2004

AbstractAn N‐dodecylated chitosan (CS‐12) was synthesized from dodecyl bromide and chitosan and was assembled with DNA to form a polyelectrolyte complex (DNA/CS‐12 PEC). UV was used to examine the thermal stability of DNA embedded in PEC. The results indicate that the incorporation of dodecylated chitosan can enhance the thermal stability of DNA. The analysis of AFM image shows that PEC develops a globule‐like structure composed of 40–115 DNA molecules. Dissociation of PEC was investigated by the addition of low molecular weight electrolytes. The added small molecular salts dissociate the PEC, inducing DNA to release. The ability of Mg2+ to dissociate PEC is greater compared to that of Na+ and K+. From AFM images, it can be visualized that DNA remains intact and undamaged due to the protection from DNase offered by alkylated chitosan. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3391–3395, 2001
Single‐point determination of intrinsic viscosity of wholly aromatic thermotropic copolyesters in 1,1,1,3,3,3‐hexafluoro‐2‐propanol
Authors: Liu Yongjian 
Published: October 2004

AbstractA series of wholly aromatic thermotropic copolyesters based on 4‐hydroxybenzoic acid, hydroquinone, and 2,6‐naphthalene dicarboxylic acid were synthesized by direct melt polymerization with or without different added transesterification catalysts. Nine procedures for calculation of the intrinsic viscosities from a single viscosity measurement for polymer solutions, including a proposed one, were applied for the thermotropic copolyesters in 1,1,1,3,3,3‐hexafluoro‐2‐propanol at 30°C. Various forms of the Huggins and Kraemer equations, singly or combined, yielded intrinsic viscosities that were in good agreement with extrapolated values obtained in the usual manner from multipoint viscosity measurements over a wide range of concentrations. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3396–3401, 2001