bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water‐soluble/dispersible cationic pressure‐sensitive adhesives. I. Adhesives from solution polymerization
Authors: Yan Zegui , Deng Yulin 
Published: September 2003

AbstractPressure‐sensitive adhesives (PSAs) have long been a problem as sticky contaminants for paper recycling mills. The main problem associated with such stickies is that the PSAs in the waste papers deposit on the felts, press rolls, and drying cylinders of paper machines, and this creates problems with paper formation, reducing the paper quality and paper machine runnability. The annual cost of stickies to the U.S. paper industry is estimated to be about $600,000,000–650,000,000. To solve this problem, a series of cationic water‐soluble/dispersible PSAs have been synthesized by the free‐radical solution polymerization of butyl acrylate and [3‐(methacryloylamino)propyl]trimethylammonium chloride in ethanol. The PSA end‐use properties, repulpability in paper recycling, and the effects on the properties of recycled paper products have been studied. The cationic PSAs can be dissolved or dispersed in water if the cationic charge density in the PSA backbone is controlled, and so they do not deposit as stickies during recycling and papermaking processes. Because the PSAs are cationically charged, they can easily be removed from the papermaking system by adsorption onto the negatively charged fibers and fine surfaces. Furthermore, the adsorbed colloidal or dissolved PSAs have little effect on the final paper properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1624–1630, 2003
Mechanochemical surface activation of ground tire rubber by solid‐state devulcanization and grafting
Authors: Cavalieri F. , Padella F. , Cataldo F. 
Published: September 2003

AbstractCured rubber powder was successfully devulcanized under the application of high‐energy ball milling. An attempt was made to improve the efficiency of devulcanization with a phenolic antioxidant (2,6‐di‐tert‐butyl‐4‐methyl‐phenol). In addition, the grafting of virgin natural rubber to the surface of rubber powder was promoted by milling under an inert atmosphere. The extent of mechanochemical devulcanization was studied by estimation of the sol–gel fractions and crosslink densities. Our findings suggest that the process led to a preferential breakage of sulfur crosslinks. The curing behavior of the compounds and the mechanical properties of the vulcanizates containing treated rubber powder and fresh rubber were investigated. The chemical and mechanical properties depended strongly on the experimental milling conditions, which could consequently be controlled to improve the quality of the reclaimed rubber. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1631–1638, 2003
Thermal and mechanical properties of a polypropylene nanocomposite
Authors: Ellis Thomas S. , D'Angelo Joseph S. 
Published: September 2003

AbstractAn experimental polypropylene (PP) nanocomposite, containing approximately 4 wt % of an organophilic montmorillonite clay, was prepared and characterized, and its properties were compared with those of talc‐filled (20–40 wt %) compositions. Weight reduction, with maintained or even improved flexural and tensile moduli, especially at temperatures up to 70°C, was a major driving force behind this work. By a comparison with the analytical data from a nylon 6 (PA‐6) nanocomposite, it was found that the PP nanocomposite contained well‐dispersed, intercalated clay particles; however, X‐ray diffraction, transmission electron microscopy, dynamic mechanical analysis, and permeability measurements confirmed that exfoliation of the clay in PP was largely absent. The increased glass‐transition temperature (Tg) of a PA‐6 nanocomposite, which possessed fully exfoliated particles, indicated the molecular character of the matrix–particle interaction, whereas the PP nanocomposite exhibited simple matrix–filler interactions with no increase in Tg. The PP nanocomposite exhibited a weight reduction of approximately 12% in comparison with the 20% talc‐filled PP, while maintaining comparable stiffness. Undoubtedly, considerable advantages may be available if a fully exfoliated PP nanocomposite is fabricated; however, with the materials available, a combination of talc, or alternative reinforcements, and nanocomposite filler particles may provide optimum performance. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1639–1647, 2003
Kinetic study of radical polymerization. II. Solid‐state bulk polymerization of sodium methacrylate by differential scanning calorimetry
Authors: Mahdavian Ali‐Reza , Zandi Mojgan 
Published: September 2003

AbstractThe solid‐state radical polymerization of sodium methacrylate was investigated. It was initiated by azobisisobutyronitrile, which was used as a radical initiator. Differential scanning calorimetry (DSC) was used to observe the endothermic and exothermic transitions during the polymerization reaction. Structural studies were performed with the DSC thermograms and Fourier transform infrared and ultraviolet–visible spectra, and all of the results confirmed the progress of the reaction. The obtained data revealed that the polymerization reaction proceeded completely with a 100% conversion. ΔH of this reaction was calculated with various amounts of the initiator, and the peak temperatures were determined at different heating rates. The activation energy (19.7 kcal mol−1) was also obtained by the Kissinger method for this type of solid polymerization reaction. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1648–1654, 2003
Influence of molecular weight on the domain coarsening rates in linear polyethylene–poly(ethylene‐co‐1‐octene) blends
Authors: Phochalam Noree , Tabtiang Arunee , Venables Richard A. 
Published: September 2003

AbstractThe coarsening rates of the two‐phase morphologies of linear polyethylene/poly(ethylene‐co‐1‐octene) blends were determined as functions of molecular weight. Samples with cocontinuous morphologies that were prepared through solution blending were annealed in the melt state for various times, and, subsequently the length scales of the morphologies were determined with a line‐intersection method. Length‐scale data were multiplied by a function that normalized for the effects of differences in zero‐shear‐rate viscosity and thermal energy; after normalization, the data largely fell on one trend line within the bounds of experimental error. This indicated that the principal effect of increasing molecular weight was to slow the coarsening rate through an increase in melt viscosity, with little effect from the thermodynamic compatibility of the two polymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1655–1661, 2003
Crosslinking of cotton cellulose in the presence of alkyl diallyl ammonium salts. I. Physical properties and agent distribution
Authors: Chen Jui‐Chin , Yeh Jen‐Taut , Chen Cheng‐Chi 
Published: September 2003

AbstractWe used three kinds of alkyl diallyl ammonium salts (methyl, ethyl, and propyl) in combination with dimethyloldihydroxyethyleneurea (DMDHEU) as crosslinking agents. The nitrogen content, dry crease recovery angle (DCRA), moisture regain, and wicking height for the DMDHEU/alkyl diallyl ammonium salts were in the order of CH3 > C2H5 > C3H7, but the wet crease recovery angle (WCRA) and tensile strength retention (TSR) were in the opposite order at the same resin concentration. For the same DCRA and TSR, the WCRA values for only DMDHEU were lower than those for DMDHEU/alkyl diallyl ammonium salts, and the WCRA values for DMDHEU/alkyl diallyl ammonium salts were in the order of C3H7 > C2H5 > CH3. Both the OH group of the cellulose and DMDHEU could react with the vinyl or epoxy groups of the alkyl diallyl ammonium salts during the pad–dry–cure process. The surface migration for DMDHEU/alkyl diallyl ammonium salts was in the order of CH3 > C2H5 > C3H7. Fabrics treated with DMDHEU/alkyl diallyl ammonium salts showed good antibacterial properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1662–1669, 2003
Microhardness of styrene/butadiene block copolymer systems: Influence of molecular architecture
Authors: Michler G. H. , Baltá‐Calleja F. J. , Puente I. , Cagiao M. E. , Knoll K. , Henning S. , Adhikari R. 
Published: September 2003

AbstractThe influence of molecular architecture on the mechanical properties of styrene/butadiene block copolymers was investigated by means of the microhardness technique. It was found that the microhardness of the styrene/butadiene block copolymers is dictated by the nature of microphase separated morphology. In contrast to polymer blends and random copolymers, in which the microhardness generally follows the additivity rule, the behavior of the investigated block copolymers was found to significantly deviate depending on their molecular architecture. The glass‐transition temperature of the polystyrene phase (Tg‐PS), which practically remained constant and that of the polybutadiene phase (Tg‐PB), which varied with the change in the block copolymer architecture, apparently do not influence the microhardness values of the block copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1670–1677, 2003
Curing behavior of a novolac‐type phenolic resin analyzed by differential scanning calorimetry
Authors: De Medeiros Eliton S. , Agnelli José A. M. , Joseph Kuruvilla , De Carvalho Laura H. , Mattoso Luiz H. C. 
Published: September 2003

AbstractCuring of a novolac‐type phenolic resin was studied by DSC. The kinetic analysis was performed by means of the dynamic Ozawa method at heating rates of 5, 10, 15, and 20°C/min. This analysis was used to determine the kinetic parameters of the curing process. The activation energy was found to be 144 kJ/mol. It was found that the Ozawa exponent values decreased with increasing reaction temperature from 3.5 to 1, suggesting a change in the reaction mechanism from microgel growth to diffusion‐controlled reaction. The reaction rate constant was found to range from 123.0 to 33.6 (°C/min)n. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1678–1682, 2003
Thermoreversible hydrogels. XIX. Synthesis and swelling behavior and drug release behavior for the N‐isopropylacrylamide/poly(ethylene glycol) methylether acrylate copolymeric hydrogels
Authors: Lee Wen‐Fu , Lin Yu‐Hung 
Published: September 2003

AbstractA series of thermosensitive copolymeric hydrogels were prepared from various molar ratios of N‐isopropylacrylamide (NIPAAm) and poly(ethylene glycol) methylether acrylate (PEGMEAn), which was synthesized from acryloyl chloride and poly(ethylene glycol) mono methylether with three oxyethylene chain lengths. Investigation of the effect of the chain length of oxyethylene in PEGMEAn, and the amount of the PEGMEAn in the NIPAAm/PEGMEAn copolymeric gels, on swelling behavior in deionized water was the main purpose of this study. Results showed that the swelling ratio for the present copolymeric gels increased with increasing chain length of oxyethylene in PEGMEAn and also increased with increase in the amount of PEGMEAn in the copolymeric gels. However, the gel strength and effective crosslinking density of these gels decreased with increase in swelling ratio. Some kinetic parameters were also evaluated in this study. Finally, the drug release and drug delivery behavior for these gels were also assessed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1683–1691, 2003
Synthesis and thermal properties of polystyrene/montmorillonite nanocomposites by γ‐ray radiation polymerization
Authors: Zhang Wei‐An , Shen Xiao‐Feng , Liu Ming‐Fei , Fang Yue‐E 
Published: September 2003

AbstractPolystyrene/montmorillonite nanocomposites were prepared by γ‐ray radiation polymerization. X‐ray diffraction and high‐resolution transmission electron microscopy confirmed that polystyrene (PS) could be easily inserted between the sheets of montmorillonite (MMT) to form intercalated nanocomposites. In these PS/MMT nanocomposites, the distance between the sheets of MMT was barely influenced by varying the content of the MMT. Thermal stabilities of the samples were studied by thermal gravimetric analysis and differential scanning calorimetry. The glass‐transition temperature of PS/MMT nanocomposites was obviously higher than that of the pure PS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1692–1696, 2003
The “cold‐solutioning” phenomenon in cellulose triacetate–acetone mixtures
Authors: Variankaval N. E. , Rezac M. E. , Abhiraman A. S. 
Published: September 2003

AbstractDirect mixing of cellulose triacetate (CTA) in acetone at room temperature produces only an opaque swollen gel at all concentrations. However, cycling the mixture between room temperature and −78 ± 3°C results in a stable solution at room temperature, if the concentration is less than 6% (w/w). This process has been called “cold‐solutioning.” Such a process also produces a clear solution at concentrations between 6% (w/w) and 10% (w/w); however, in time, the solution separates slowly into at least two phases, a clear liquid and an opaque gel phase. At concentrations above 10% (w/w) and below 20% (w/w), the system exhibits two phases. A completely opaque swollen gel forms at concentrations of 20% (w/w) and above. The above‐described cold‐solutioning phenomena are shown to be the coupled kinetic and thermodynamic consequences of (1) the large thermal stresses that would result from thawing a swollen mixture of CTA and acetone, arising from the large differences in their thermal expansion coefficients; and (2) the “bimodal” composition of the cellulose derivative. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1697–1707, 2003
Effect of Ni(II), Cd(II), and Cu(II) metal ions on the crystallinity of poly(maleic anhydride‐alt‐acrylic acid)
Authors: Kavlak Serap , Kaplan Can Hatice , Güner Ali , Rzaev Zakir 
Published: September 2003

AbstractThe chelation of poly(maleic anhydride‐alt‐acrylic acid) [poly(MA‐alt‐AA)] with nickel (II), cadmium (II), and copper (II) ions was carried out under various pH conditions. Polychelates were prepared by precipitation from the aqueous solutions of metal salts at different pH values. The effects of metal salts (NiCl2·6H2O, CdCl2·2H2O, CuCl2·2H2O) on the degree of crystallinity of poly(MA‐alt‐AA) were investigated by X‐ray diffraction spectroscopy at different pH values. The degree of crystallinity was found to be in the following order: Cd(II)–polychelate > Cu(II)–polychelate > Ni(II)–polychelate at pH 6.36; this result was also supported by gravimetric studies. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1708–1715, 2003
Tensile modulus modeling of carbon‐filled nylon 6,6 and polycarbonate‐based resins
Authors: Konell Jeremiah P. , King Julia A. , Miskioglu Ibrahim 
Published: September 2003

AbstractElectrically and thermally conductive resins can be produced by adding conductive fillers to insulating polymers. Mechanical properties, such as tensile modulus, are also important. This research focused on performing compounding runs followed by injection molding and tensile testing of carbon‐filled nylon 6,6 and polycarbonate‐based resins. The three carbon fillers investigated included an electrically conductive carbon black, synthetic graphite particles, and a milled pitch–based carbon fiber. For each polymer, resins were produced and tested that contained varying amounts of these single‐carbon fillers. In addition, combinations of fillers were investigated by conducting a full 23 factorial design and a complete replicate in each polymer. These tensile modulus experimental results were then compared to results predicted by several different models. For the composites containing only one filler type, the Nielsen model with the modified Ψ term provided the best prediction of the actual experimental values. For the composites containing more than one filler type, a new parameter, which includes the vibrated bulk density (VBD) of the fillers, was incorporated into the Nielsen model with the modified Ψ term. This model with the new VBD parameter provided the best estimate of experimental tensile modulus for composites containing multiple‐filler types. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1716–1728, 2003
Characterization of the free volume in high‐impact polystyrene/polypropylene and high‐impact polystyrene/high‐density polyethylene blends probed by positron annihilation spectroscopy
Authors: Hu Youhua , Qi Chenze , Liu Weiming , Wang Baoyi , Zheng Houtian , Sun Xudong , Zheng Xiaoming 
Published: September 2003

AbstractThe free‐volume properties of high‐impact polystyrene (HIPS)/polypropylene (PP) and HIPS/high‐density polyethylene (HDPE) blends were investigated by means of positron annihilation lifetime spectroscopy (PALS). The measured results show that the free‐volume holes in the semicrystalline polymers, such as PP and HDPE, were not large enough to accommodate the branched chains and the end groups of the macromolecular chains in HIPS to produce favorable interactions between the semicrystalline polymers and the HIPS polymer in these blends; thus immiscible blends were formed. The weak interaction between two dissimilar polymer molecules only took place in the regions between two amorphous phases. In addition, the observed negative deviations of the longest lifetime intensity and the free‐volume fraction were attributed to the influence of the interfacial polarization during PALS measurement. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1507–1514, 2003
Effect of humidified feeds on oxygen permeability of mixed matrix membranes
Authors: Moore Theodore T. , Vo Trinh , Mahajan Rajiv , Kulkarni Sudhir , Hasse Dave , Koros William J. 
Published: September 2003

AbstractHybrid inorganic/organic membranes, often called mixed matrix membranes, are composed of (inorganic) molecular sieves dispersed in a continuous (organic) polymer matrix. Recent studies have demonstrated that mixed matrix membranes have the potential to exceed the performance of conventional polymer membranes while maintaining their processability. Because water vapor can be present in air and in natural gas feeds, it is an ideal candidate for studying the effects of strongly sorbing minor components on mixed matrix membranes. Water vapor has been shown to cause complex but predictable effects on mixed matrix materials. In this article simple models are proposed to describe the behavior of mixed matrix membranes with humidified feeds to assist in interpreting observed performance. This research has shown that mixed matrix membranes composed of zeolite 4A dispersed in poly(vinyl acetate) are adversely affected by water adsorbed in the pores of zeolite 4A. On the other hand, a novel, more hydrophobic molecular sieve, SSZ‐13, appears to be an ideal candidate for mixed matrix membranes because it has improved transport properties over zeolite 4A and is less affected by sorbed water. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1574–1580, 2003
Reticular groove and reticulum are innervated by myenteric neurons with different neurochemical codes
Authors: Pfannkuche Helga , Schellhorn Corinna , Schemann Michael , Gäbel Gotthold 
Published: September 2003

AbstractThe reticulum and the reticular groove are functional distinct compartments within the ovine forestomach. While the reticulum takes part in various motor functions, such as mixing, retaining, and rejecting the forestomach ingesta, the reticular groove serves mainly as a bypass between the esophagus and the abomasum. To accomplish these different tasks, the compartments develop specific motility patterns that are controlled by intrinsic neural circuits. In this study the intrinsic innervation by myenteric neurons was analyzed by quadruple immunohistochemistry against cholineacetyl transferase (ChAT), nitric oxide synthase (NOS), substance P (SP), and vasoactive intestinal peptide (VIP). Four neurochemically different subpopulations of myenteric neurons were found in the reticulum and the floor of the reticular groove: ChAT/–, ChAT/SP, NOS/–, and NOS/VIP. The neuronal proportions were calculated relative to all myenteric neurons. Neurons of the reticulum were mostly immunoreactive for ChAT (89% ± 3%), whereas neurons adjacent to the reticular groove predominantly expressed a nitrergic phenotype (62% ± 4%). ChAT‐positive neurons were also immunoreactive for SP (ChAT/SP: 64% ± 3% reticulum; 25% ± 1% reticular groove) or were purely cholinergic (ChAT/–: 25% ± 4% reticulum; 13% ± 3% reticular groove). NOS‐positive neurons colocalized VIP (NOS/VIP: 10% ± 3% reticulum; 46% ± 1% reticular groove) or none of the other neurotransmitters (NOS/–: 1% ± 1% reticulum; 17% ± 3% reticular groove). Analysis of the soma sizes revealed that in both compartments the nitrergic neurons were significantly larger than the cholinergic neurons. It is suggested that the specific neurochemical code in combination with a specific morphology leads to a precise regulation of the specialized tasks of the reticulum and reticular groove by subpopulations of myenteric neurons. Anat Rec Part A 274A:917–922, 2003. © 2003 Wiley‐Liss, Inc.
CD40 and CD40L expression in the chicken embryo aorta: Possible role in the endothelial–mesenchymal transdifferentiation process
Authors: Arciniegas Enrique , Becerra Aniuska , de Sanctis Juan B. , Graterol Armando , Ramírez Richard 
Published: September 2003

AbstractEndothelial–mesenchymal transdifferentiation (EMT) is believed to play a crucial role in embryonic vascular development and intimal thickening, which contributes to the pathogenesis of atherosclerotic lesions. However, the mechanisms by which it occurs, as well as the signals that control it, have not yet been elucidated. Given the important role played by the CD40‐CD40 ligand (CD40L) system during the initiation and progress of atherosclerosis, we investigated whether both CD40 and CD40L were present in the aortic wall during EMT and the advanced stages of chicken embryo development. CD40‐CD40L expression was found on endothelial cells (ECs), mesenchymal cells, and smooth muscle cells (SMCs) at all stages examined, and appeared to be distributed across the aortic wall. However, some notable differences between the expression patterns were observed. CD40 had a more restricted distribution compared to CD40L, and did not stain every cell type of the aortic wall. According to immunoblotting and enzyme‐linked immunosorbent assay (ELISA) analyses, the CD40L content was highest at day 7 of development. An important and novel finding was the expression of CD40L in areas where ECs transdifferentiate into mesenchymal cells. Specifically, CD40L was associated to the surface of cells that were detaching and migrating from the monolayer of ECs, whereas for CD40 a very diffuse subcellular localization was seen at the monolayer and the detaching and migrating cells. These data suggest a possible role for CD40‐CD40L interactions during EMT and the remodeling of the aorta. Anat Rec Part A 274A:942–951, 2003. © 2003 Wiley‐Liss, Inc.