bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of cationic polyacrylamide in fiber‐CaCO3 pigment interactions
Authors: Alince B. , Bednar F. 
Published: March 2003

AbstractIt is believed that the action of cationic polyacrylamide as a retention aid for incorporating pigment particles into a paper is based on its ability to form a polymeric bridge between particles and pulp fiber suspended in water. When the polymer is added to a mixture of fibers and pigments, this process is complicated by the different rates of polymer adsorption on the fibers and the pigment particles, the rate of collision between them, and the charge reversal of the polymer from the hydrolysis. To elucidate under which conditions the polymer can form a bridge, the processes of polymer adsorption and pigment–fiber interaction were separated. A deposition of pigment particles onto fibers suspended in water was investigated, using both components pretreated with the polymer. The results indicated that polymer adsorbed on fiber can form a bridge with untreated pigment particles regardless of the polymer charge. On the other hand, negatively charged hydrolyzed polymer adsorbed on the pigment does not form a bridge with untreated fiber. When both the fiber and the pigment are pretreated, the bridge formation depends on their surface coverage by polymer and its charge. No deposition takes place when both components are sufficiently coated by anionic hydrolyzed polymer, which indicates electrosteric repulsion. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2409–2415, 2003
Physical, mechanical, and biocompatibility evaluation of three different types of silicone rubber
Authors: Fallahi D. , Mirzadeh H. , Khorasani M. T. 
Published: March 2003

AbstractSilicone rubber as a valuable biomaterial is widely used in medical applications, but its surface properties and low wettability make serious problems in long‐term implants. This work was undertaken to evaluate the biocompatibility of modified silicone rubber using two different techniques. A blend of poly(acrylamide) and silicone rubber was compared with virgin silicone surfaces as well as with those modified by laser treatment. Physical and mechanical properties of the samples were examined using different techniques. The hydrophilicity of the silicone rubber increased with increasing hydrogel content and decreased as a result of laser treatment. Both fibroblast cell (L929) and platelet behavior in contact with these surfaces were evaluated in vitro. The morphology of fibroblast cells that adhered to the blends was similar to the control. In contrast, on the laser‐treated surfaces fibroblast cells showed different proliferation. On the other hand, fewer platelets adhered to the laser‐treated surface than adhered to the blend and the unmodified PDMS surfaces. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2522–2529, 2003
Precipitation polymerization of methyl methacrylate in tetrahydrofuran with compressed CO2 as antisolvent
Authors: Xu Qun , Han Buxing , Yan Haike 
Published: March 2003

AbstractPrecipitation polymerization of methyl methacrylate (MMA) in tetrahydrofuran (THF) with compressed CO2 as an antisolvent was carried out at 335 K up to 8.5 MPa, and the decomposition rate of the initiator, 2,2′‐azobisisobutyronitrile (AIBN), was studied with UV/vis. Gel permeation chromatography (GPC) and differential scanning calorimetry (DSC) were used to determine the average molecular weights and glass transition temperature (Tg), and scanning electron micrography (SEM) was used to observe the morphologies of the product. The results showed that the average molecular weights of the polymer vary considerably with the volume expansion of the solution induced by compressed CO2. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2427–2433, 2003
Enhancement of antifillet cracking performance for no‐flow underfill by toughening method
Authors: Moon Kyoung‐Sik , Fan Lianhua , Wong C. P. 
Published: March 2003

AbstractFillet cracking of no‐flow underfill in a flip‐chip device during a reliability test such as thermal shock or thermal cycling has been a serious reliability problem. The effect of toughening agents and modification of epoxy on fillet cracking of no‐flow underfill was investigated. The best epoxy formulation and the appropriate loading level of toughening agent regarding the antifillet cracking performance were found. In the case where the epoxy was modified with polysiloxanes, the second‐phase particle with a submicron particle size was formed and the size of the particle depended on the kind of toughening agent. The morphology was observed by a scanning electron microscopy and confirmed by a dynamic mechanical analyzer measurement. The physical properties such as the fracture toughness, flexual modulus, coefficient of thermal expansion, and adhesion were measured, and the liquid–liquid thermal shock (LLTS) test under −55 to 125°C was performed with different formulations. One of the formulations toughened by amine/epoxy‐terminated polysiloxane, which has higher die shear strength, lower modulus, and higher toughness, passed 1000 cycles of the LLTS test. In order to obtain a high reliable no‐flow underfill, the physical properties of the no‐flow underfill should be well controlled and balanced. Finally, a correlation between physical properties of the no‐flow underfill and the fillet cracking capability for those approaches was discussed. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2439–2449, 2003
Experimental study of the frictional properties of friction spun yarns
Authors: Ramkumar S. S. , Shastri L. , Tock R. W. , Shelly D. C. , Smith M. L. , Padmanabhan S. 
Published: March 2003

AbstractThis article reports the results from a study conducted to characterize the frictional properties of friction spun yarns. The aim of the study was to obtain data on the surface mechanical properties of a variety of friction spun yarns. The study was essential as the surface mechanical properties influence the fabric formation, bonding strength, and high‐performance properties of yarns. The yarns used in the study were made from different fibers and were spun at different speeds. The capstan method was used to obtain the friction force values between the yarns and a glass cylindrical rod. The experiment was conducted at different tensions. The results indicate that the friction of friction spun yarns are influenced by different factors such as the type of fiber and tensions applied. The results obtained help to understand the surface mechanical properties of high‐performance yarns and their influence on the performance characteristics of friction spun yarns. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2450–2454, 2003
Study of thermal stability and ablation behavior of carbon/epoxy‐novolac composites
Authors: Firouzmanesh M. R. , Azar A. Aref 
Published: March 2003

AbstractThe use of carbon/epoxy‐novolac composites as advanced ablative materials for insulation of exit cone of solid‐propellant rocket nozzles are studied. In this article, three types of carbon fabrics are used and their composites are prepared by use of impregnation and hand lay‐up methods. To study the thermal stability and ablation behavior, these composites are tested by thermal tests such as thermogravimetric analysis (TGA) and oxyacetylene standard flame tests; the latter test is one of the most important standard tests of ablative materials. The test apparatus is made according to American standard, ASTM‐E‐285‐80, and over 33 polymeric composites and 3 steel specimens were carried out according to its standards. It is found that the composites that are made up of C‐9750 fabric (high‐strength carbon fabric) in comparison with steel and the other types of carbon fabric specimens have the highest thermal stability and the best ablation behavior. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2455–2461, 2003
Synthesis and characterization of nylons based on hexadecane diacid
Authors: Li Weihua , Yan Deyue 
Published: March 2003

AbstractA series of nylons with long alkane segments between amide groups were synthesized by using hexadecane diacid and various diamines, and the resulting polyamides were characterized comprehensively. It was shown that the molecular weights of nylons 6 16, 8 16, 10 16, and 12 16 in our studies exceed 1.1 × 104, whereas nylons 2 16 and 4 16 have relatively low molecular weights. In addition, the melting temperatures, the decomposition temperatures, and the glass transition temperatures of the nylons obtained were measured. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2462–2467, 2003
Investigation of kinetics of 4‐methylpentene‐1 polymerization using Ziegler–Natta‐type catalysts
Authors: Balaji R. , Kothandaraman H. , Rajarathnam D. 
Published: March 2003

AbstractThe kinetics of 4‐methylpentene‐1 (4MP1) polymerization by use of Ziegler–Natta‐type catalyst systems, M(acac)3‐AlEt3 (M = Cr, Mn, Fe, and Co), are investigated in benzene medium at 40°C. The effect of various parameters such as Al/M ratio, reaction time, aging time, temperature, catalyst, and monomer concentrations on the rate of polymerization and yield are examined. The rate of polymerization increased linearly with increasing monomer concentration with first‐order dependence, whereas the rate of polymerization with respect to catalyst concentration is found to be 0.5. For all cases, the polymer yield is maximum at an Al/M ratio of 2. The activation energies obtained from linear Arrhenius plots are in the range of 25.27–33.51 kJ mol−1. It is found that the aging time to give maximum percentage yield of the polymer varies with the catalyst systems. Based on the experimental results, a plausible mechanism is proposed that envisages a free‐radical mechanism. Characterization of the resulting polymer product, for all the cases, through FTIR, 1H‐NMR, and 13C‐NMR studies, showed isomerized polymeric structures with 1,4‐structure as dominant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2468–2477, 2003
Studies on mechanical and rheological properties of poly(vinyl chloride) modified with elastomers and rigid organic particles
Authors: Peng Jing , Wei Genshuan , Zhang Yudong 
Published: March 2003

AbstractChlorinated polypropylene (CPP) as rigid organic particles and chlorinated polyethylene (CPE) as elastomer were used to modify the properties of poly(vinyl chloride) (PVC) by melt blending. Both mechanical and rheological properties of the PVC blends were investigated. The submicroscopic morphology of the blends was observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results demonstrate that when the weight ratio of CPE to CPP is about 6 : 1, a sample with the best impact strength and without obvious decline in tensile strength can be obtained. The impact strength correlates well with SEM morphologies, and TEM micrographs in the necking of the tensile specimen indicate that a cold‐drawing deformation of rigid particles happens as reported by T. Kurauchi and T. Ohta (J Mater Sci 1984, 19, 1699). Therefore, a conclusion can be drawn that CPP particles acting similar to elastic particles can toughen PVC, and the cold‐drawing deformation is the primary reason for toughening the PVC blends. In addition, the addition of CPP can promote the processibility of PVC ternary blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2478–2483, 2003
Use of gradient, critical, and two‐dimensional chromatography in the analysis of styrene‐ and methyl methacrylate‐grafted epoxidized natural rubber
Authors: Graef Sven M. , Van Zyl André J. P. , Sanderson Ronald D. , Klumperman Bert , Pasch Harald 
Published: March 2003

AbstractThe growing number of heterogeneous polymeric species that are being synthesized places increasing demands on existing analytical techniques. Although size‐exclusion chromatography (SEC) has established itself as a powerful analytical tool, it has its limits when complex polymers, e.g., graft copolymers, must be analyzed. In this case, complementary techniques such as gradient HPLC and liquid chromatography at critical conditions (LCCC) are more favorable. The present study describes the synthesis and analysis of methyl methacrylate‐ and styrene‐grafted epoxidized natural rubber by different chromatographic techniques. The grafting efficiency was evaluated by gradient HPLC under normal and reversed phase conditions. Methyl methacrylate‐grafted ENR50 was further analyzed by LCCC, where separation of the rubber and grafted rubber occurred according to chemical composition but was independent of the molar mass of the methyl methacrylate homopolymers. This was followed by the combination of LCCC and SEC, where separation was achieved in two dimensions. Relevant deductions were made of both the chemical composition distribution and the molar mass distribution of the functional groups of methyl methacrylate‐grafted ENR50. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2530–2538, 2003
Monitoring the grafting of epoxidized natural rubber by size‐exclusion chromatography coupled to FTIR spectroscopy
Authors: Van Zyl André J. P. , Graef Sven M. , Sanderson Ronald D. , Klumperman Bert , Pasch Harald 
Published: March 2003

AbstractThe evaluation of heterogeneous polymeric species by a selective, dual detector size‐exclusion chromatography setup can provide accurate results on the incorporation of specific functional groups in copolymers as a function of the molar mass distribution. However, when non‐UV‐absorbing species are used in copolymerization reactions, the dual detector method becomes less reliable. By interfacing a Fourier transform infrared (FTIR) spectrometer with size‐exclusion chromatography (SEC), the problem can be overcome, making it possible to map non‐UV‐absorbing species as a function of the molar mass distribution. Coupling takes place via a solvent‐evaporation stage, which delivers the mobile phase as a dry, solvent‐free polymeric film onto a germanium disk. In this article, styrene and methyl methacrylate were grafted onto epoxidized natural rubber (ENR50) and analyzed by SEC. The accuracy of FTIR as a suitable detector was evaluated by comparing results from a dual detector SEC setup and FTIR coupled to SEC. FTIR proved to be a successful detector for the analysis of non‐UV‐absorbing species. This was consequently followed by the characterization of methyl methacrylate‐grafted ENR50. From the relevant data, Gram–Schmidt and contour plots could be made to indicate the incorporation of methyl methacrylate into the grafted epoxidized natural rubber as a function of the molar mass distribution. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2539–2549, 2003
Modification of sandy soil using water‐borne polymer
Authors: Al‐Khanbashi Abdullah , El‐Gamal Maisa 
Published: March 2003

AbstractA new polymeric system has been applied for structural modification of (noncompactable) sandy soils. The system is based on a water‐borne styrene acrylic polymeric formulation (emulsion) containing varying amounts of solid polymer. The present work deals with system optimization and measurements designed to examine the effects of polymer content on hydraulic conductivity and compressive strength. Samples were prepared from prescribed amounts of polymer, water, and sand by using two different preparations methods (mixing and spraying). Measurements of hydraulic conductivity for both sets of samples were conducted in a flexible membrane test apparatus. For the first set of samples, the permeability coefficient of the sand was noted to be reduced 10‐fold (from 10−5 to 10−6 m s−1) upon the incorporation of about 2% polymer. In the second set (samples prepared with the spraying method), the hydraulic conductivity was further reduced to 7.2 × 10−7 at a polymer concentration of about 2%. Stress–strain measurements made on dry cylindrical specimens disclosed remarkable enhancement in the mechanical behavior of the system. For both types of preparation methods, the compressive strength and modulus of elasticity increased linearly with the polymer concentration in the sample. Scanning electron microscopic examination revealed that the dramatic reduction in the permeability and the improved mechanical properties are attributed to the polymer coverage of the sand particles and the development of interconnecting ties between them. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2484–2491, 2003
Graft copolymerization of methyl methacrylate onto rubber‐wood fiber using H2O2 and Fe2+ as an initiator system
Authors: Abu‐Ilaiwi Faraj A. , Ahmad Mansor B. , Ibrahim Nor Azowa , Ab. Rahman Mohamad Zaki , Md. Dahlan Khairul Zaman , Yunus Wan Md. Zin Wan 
Published: March 2003

AbstractMethyl methacrylate (MMA) was successfully grafted onto rubber‐wood fiber in a free‐radical solution polymerization initiated by ferrous ion and hydrogen peroxide. The effects of the reaction parameters (reaction temperature, reaction period, influence of hydrogen peroxide, ferrous ammonium sulfate, and monomer concentrations) were investigated. The grafting percentage showed dependency on H2O2, Fe2+, and monomer concentrations, as well as reaction temperature and reaction period. The optimum reaction temperature was determined to be about 60°C and the reaction period was 60 min. The optimum concentration of H2O2 was 0.03M and optimum amounts of Fe2+ and MMA were 0.26 mmol and 2.36 × 10−2 mol, respectively. Poly(methyl methacrylate) (PMMA) homopolymer was removed from the graft copolymer by Soxhlet extractor using acetone. The presence of PMMA on the fiber was shown by FT‐IR spectroscopy and gravimetric analysis. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2499–2503, 2003
Blend compatibilizers based on silane‐ and maleic anhydride–modified polyolefins
Authors: Nachtigall Sônia M. B. , Felix Afonso H. O. , Mauler Raquel S. 
Published: March 2003

AbstractPolypropylene (PP)/polyamide blends were compatibilized with PP modified with vinylsilane or maleic anhydride and ethylene–propylene random (EPR) copolymer modified with maleic anhydride. The thermal behavior, mechanical properties, and morphology of the blends were investigated. Thermal analysis showed that the polyamide crystallization temperatures shifted downward with all compatibilizers, whereas its melting behavior did not change. On the other hand, polypropylene crystallization temperatures shifted upward in all cases, except for blends containing EPR modified with maleic anhydride. Tensile strength and elongation at break increased for blends compatibilized with modified PP. Blends containing up to 7% of EPR modified with maleic anhydride did not show good yield stresses. The morphology of the blends showed a finer dispersion of the polyamide minor phase in the PP matrix. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2492–2498, 2003
Conducting blends of poly(o‐toluidine) and ethylene–propylene–diene terpolymer
Authors: Ghosh Premamoy , Kar Swarnendu B. , Bhattacharyya Sanchita 
Published: March 2003

AbstractPoly(o‐toluidine) (POT) is an electroactive polymer with poor mechanical and thermal characteristics. We examined the scope for improving such properties by making blends of POT with ethylene–propylene–diene rubber (EPDM). We prepared POT–EPDM blends containing different weight fractions of POT by intimately mixing known volumes of separate solutions of the two polymers (POT in THF and EPDM in toluene). Films of EPDM and POT–EPDM blends in solution were obtained by spreading, solvent evaporation, and film casting techniques. POT, EPDM, and their blends were characterized in solution by ultraviolet‐visible spectroscopy, and the respective dried samples were analyzed by Fourier transform infrared spectroscopy and thermogravimetry. The polymer samples were further analyzed morphologically by scanning electron microscopy, and their tensile strengths were also evaluated. Spectroscopic and thermal studies of the blends indicated some sort of interaction between the two constituent polymers. The direct current electrical conductivity of the blends in increasing order of POT loading (12.5–100%) was in the range 9.9 × 10−5 to 11.6 × 10−2 S cm−1. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2550–2555, 2003
Synthesis of polyethylene‐graft‐poly(styrene‐co‐maleic anhydride) and its compatibilizing effects on polyethylene/starch blends
Authors: Park Eun‐Soo , Yoon Jin‐San 
Published: March 2003

AbstractLow density polyethylene (LDPE) was reacted with benzoyl peroxide (BPO) and 2,2,6,6‐tetramethyl‐l‐piperidinyloxy (TEMPO) to prepare a latent macroinitiator, PE–TEMPO. Little polymer was synthesized when maleic anhydride (MAH) was bulk polymerized in the presence of the PE–TEMPO. However, addition of styrene accelerated the polymerization rate and PE‐grafted‐poly(styrene‐co‐maleic anhyride) [PE‐g‐P(ST‐co‐MAH)] was produced to a high yield. Chemical reaction between MAH units and hydroxyl groups of starch was nearly undetectable in the PE/PE‐g‐P(ST‐co‐MAH)/starch blend system, and the tensile properties of the blend were not enhanced significantly. However, addition of tetrabutyl titanate (TNBT) during the blending procedure improved the tensile properties significantly through an increased interfacial adhesion between the components in the blend system. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2434–2438, 2003
Development of scar markers for the dna‐based detection of the Asian long‐horned beetle, Anoplophora glabripennis (Motschulsky)
Authors: Kethidi Damodar R . , Roden David B. , Ladd Tim R. , Krell Peter J. , Retnakaran Arthur , Feng Qili 
Published: March 2003

AbstractDNA markers were identified for the molecular detection of the Asian long‐horned beetle (ALB), Anoplophora glabripennis (Mot.), based on sequence characterized amplified regions (SCARs) derived from random amplified polymorphic DNA (RAPD) fragments. A 2,740‐bp DNA fragment that was present only in ALB and not in other Cerambycids was identified after screening 230 random primers in a PCR‐based assay system. Three pairs of nested 22‐mer oligonucleotide primers were designed on the basis of the sequence of this fragment and were used to perform diagnostic PCR. The first pair of primers (SCAR1) amplified a single 745‐bp fragment of ALB DNA, but this did not differentiate ALB from other species. The other two pairs of SCAR primers (SCAR2 and SCAR3) amplified bands of 1,237‐ and 2,720‐bp, respectively, that were capable of differentiating ALB from other closely related non‐native and native Cerambycids, such as A. chinensis (Forster), A. malasiaca (Thomson), A. nobilis (Ganglbauer), Monochamus scutellatus (Say), Plectrodera scalator (Fab), Saperda tridentata (Olivier), and Graphisurus fasciatus (Degeer). The latter two SCAR markers could be amplified using DNA extracted from body parts of ALB such as the wing, the leg, and the antennae as well as tissues from all the developmental stages including the egg, larva, pupa, and adult. These markers were also capable of identifying ALB using the DNA extracted from frass. Our results demonstrate that the SCAR markers we have identified can be used for unambiguously identifying ALB from other closely related Cerambycids using a simple PCR procedure. Arch. Insect Biochem. Physiol. 52:193–204, 2003. © 2003 Wiley‐Liss, Inc.