bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies of the chemical and pore structures of the carbon aerogels synthesized by gelation and supercritical drying in isopropanol
Authors: Fu Ruowen , Zheng Bo , Liu Jie , Weiss Steve , Ying Jackie Y. , Dresselhaus Mildred S. , Dresselhaus Gene , Satcher Joe , Baumann Theodore
Published: January 2004

The carbon aerogels prepared by a new method through gelation and supercritical drying in isopropanol were characterized by X‐ray photoelectron spectroscopy (XPS), scanning electron microscopy, and a surface area analyzer. Their chemical structure, morphology, and pore structure are discussed. We found that all of these carbon aerogel (CA‐IPA) samples have almost the same carbon and oxygen elemental states, as well as similar oxygen‐containing groups. The curve fitting of the C1s XPS spectra of the samples for characterizing oxygen‐containing surface groups can be performed by assuming the peak type to be a Gaussian–Lorentzian Cross Product, but we cannot obtain good results using a Gaussian lineshape. When the mass density of the CA‐IPA decreases, the mesopores and macropores of the samples are found to grow, but the size and the shape of individual carbon nanoparticles in various CA‐IPA samples do not apparently change. The micropore volume of the CA‐IPA samples increases with a decrease in the mass density, while the mesopore volume has a maximum at a certain mass density. The CA‐IPA samples have a very narrow micropore distribution at about 0.5 nm. The mesopore distribution of the CA‐IPA is widened and the average pore size increases as the mass density of the sample decreases. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3060–3067, 2004
Experimental study on the treatment of volatile organic compound vapors using a photoreactor equipped with photocatalyst‐coated fabrics
Authors: Park Ok‐Hyun , Kim Chang‐Soo
Published: January 2004

In this study, methods were developed to enlarge the scope of traditional applications of titanium dioxide (TiO2) and to increase the value of felted fabric by allowing volatile organic compound (VOC) degradation as well as dust filtration in a photoreacting fabric filter. In the past, when a V–Ti mixed catalyst was used, the application of felted fabric as a support material for the catalyst was difficult because the active temperature of the catalyst ranged from 250 to 400°C. Thus, in this study catalyst‐coated felted fabric was manufactured at normal temperature conditions, and then fundamental de‐VOC performance tests were conducted under irradiation condition to develop a fabric filter having a de‐VOC function in addition to a dust‐filtration function. Toluene vapor was selected as a sample VOC because it poses health hazards, has been widely used as an organic solvent, and has been known as a compound that is difficult to dissociate. To manufacture and use a fabric filter that degrades VOCS, and removes dust particles through using photocatalyst‐coated fabrics and light sources, optimum operating conditions were obtained by observing the degradation attributed to varying the toluene‐vapor flow rate, the initial toluene concentration, flue gas humidity, TiO2 loading onto the surface of the fabric, and the intensity and wavelength of a near ultraviolet light lamp. To keep the flue gas humidity at a relatively constant level, a system to automatically control the humidity was constructed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3174–3179, 2004
Polyetherols from isocyanuric acid and ethylene carbonate
Authors: Poplewska Izabela , Wȩglowska Elwira , Lubczak Jacek
Published: January 2004

A new method of preparation of polyetherols containing perhydro‐1,3,5‐triazine rings from isocyanuric acid and an excess of ethylene carbonate was developed. The course of reaction was studied at various molar ratios of reagents. The structure of the products was established, and some physical properties were measured. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2750–2755, 2004
Cobalt(III)‐mediated microemulsion polymerization of acrylonitrile: Kinetics and particle morphology
Authors: Sahoo Prafulla K. , Samal Bijayashree , Swain Sarat K.
Published: January 2004

The catalytic effect of trans‐dichloro‐bis(ethylenediamine)cobalt(III) chloride (trans‐[Co(en)2Cl2]Cl) complex on the microemulsion polymerization of acrylonitrile, in the absence of added emulsifier, was investigated. Polymerization was studied at varying concentrations of initiator, monomer, complex, and solvent over the temperature range of 30–70°C. The overall activation energy (Ea, 39.26 kJ/mol), energy of dissociation of initiator (Ed, 61.62 kJ/mol), number of micelles (0.122 × 1018), and viscosity average molecular weight of the polymer were computed. The distribution of particle sizes was determined by transmission electron microscopy (TEM). It was found that the oil‐in‐water microemulsion polymerization was stabilized by the presence of the Co(III) complex, reducing the particle size into the nano range. The average diameters of PAN nanoparticles, obtained by TEM, were in the range of 50–150 nm at maximum conversion. The experimental particle size was mainly dependent on the concentration of complex and temperature. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3120–3126, 2004
Surface modification of polyacrylonitrile staple fibers via alkaline hydrolysis for superabsorbent applications
Authors: Gupta Murari Lal , Gupta Bhuvanesh , Oppermann Wilhelm , Hardtmann Gabriele
Published: January 2004

The alkaline hydrolysis of polyacrylonitrile staple fibers was investigated for evaluation as superabsorbent materials. Studies were performed to analyze the hydrolysis of fibers and the quantification of the developed functional groups, such as carboxyl and amide groups as well as changes in the nitrile content by means of Micro‐ATR. Dyeing of the samples with methylene blue was carried out to monitor the carboxyl groups formed during the hydrolysis. A gradual decrease in the nitrile groups and built up of the carboxyl and the amide groups was observed during the hydrolysis. Microscopic investigation carried out to investigate the surface structure of hydrolyzed fibers. Hydrolysis led to surface nonhomogeneity and erosion that was dependent on the hydrolysis conditions. The fibers showed good water retention behavior, making them superabsorbent materials. The dyeing showed more intense coloration in the surface region of the modified fibers. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3127–3133, 2004
Glycidyl methacrylate–grafted linear low‐density polyethylene fabrication and application for polyester/polyethylene bonding
Authors: Pesneau Isabelle , Champagne Michel F. , Huneault Michel A.
Published: January 2004

The grafting of glycidyl methacrylate (GMA) onto linear low‐density polyethylene (LLDPE) was investigated. The grafting was performed by free‐radical grafting in the melt state in a twin‐screw extruder using an organic peroxide as initiator. The effect of initial GMA and peroxide concentration, styrene comonomer addition, as well as initial resin viscosity, on the final content in grafted moieties, unbound homopolymer, and unreacted monomer was assessed. The effect of process parameters such as flow rate, screw rotation speed, and barrel temperature was also investigated. Chemical composition was shown to be the main parameter for controlling grafting level and grafting efficiency. Grafting levels up to 1.8% and efficiency of 90% were reported even though in most conditions, the graft efficiency was severely decreased by the homopolymerization of GMA into polyGMA chains not bound to LLDPE. Finally, the effect of grafting level and the presence of unbound GMA‐based species on the efficiency GMA‐grafted LLDPE as adhesive between polyethylene and polyester were discussed. Good adhesion to poly(ethylene terephthalate) copolymer was found for low viscosity grafted polyethylene resins. A significant improvement in adhesive strength on polyester was observed when the molecular weight of the grafted LLDPE was increased. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3180–3191, 2004
Facile synthesis of poly(4‐hydroxy styrene) from polystyrene
Authors: Deokar S. , Ghadage R. S. , Rajan C. R. , Ponrathnam S.
Published: January 2004

A facile methodology to modify polystyrene, to incorporate alkali soluble hydroxy groups, is reported. Polystyrene of well‐defined number‐average molecular weights in the range of 3000 to 50,000 were prepared by suspension polymerization at 80°C by varying the relative mole ratio of carbon tetrachloride, used as chain transfer agent. Polystyrenes were acetylated; the acetyl groups were converted to acetoxy groups, by Baeyer–Villiger oxidation, and hydrolyzed in a nonaqueous alkaline medium to generate hydroxy groups. The extents of modifications were monitored by infrared spectroscopy. The glass transition temperatures of poly(4‐acetylstyrene‐co‐styrene), poly(4‐acetylstyrene‐co‐4‐acetoxystyrene‐co‐styrene), and poly(4‐hydroxystyrene‐co‐4‐acetylstyrene‐co‐styrene) were 107, 134, and 142°C, respectively. The polymers were evaluated in photoresist formulations. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3192–3201, 2004
In situ polymerization of unfluorinated and fluorinated acrylic copolymers for the conservation of stone
Authors: Vicini Silvia , Princi Elisabetta , Pedemonte Enrico , Lazzari Massimo , Chiantore Oscar
Published: January 2004

The effectiveness of butyl methacrylate/ethyl acrylate–based copolymers as consolidants for stone was investigated. The penetration of polymeric consolidating products is extremely slight because of their macromolecular nature and in situ polymerization of the monomers is suggested as an alternative technique to the use of macromolecular solutions. The efficiencies of three products synthesized in situ and fluorinated by various copolymers were comparatively evaluated in terms of surface properties, water permeability, and consolidation on a selected stone substrate. Moreover, because the environmental stability of such polymeric products is one of the key factors for their extensive application for conservative treatments, the photooxidative stability of reference polymers prepared in vitro was also investigated. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3202–3213, 2004
Polymerization rate modeling of ethylene polymerization with supported chromium oxide catalysts
Authors: Choi Kyu Yong , Tang Shihua
Published: January 2004

Supported chromium oxide catalysts have long been used for the polymerization of ethylene to high‐density polyethylene. Unlike Ziegler–Natta catalysts, chromium oxide catalyst systems do not require cocatalysts to obtain high polymerization activity. One of the most distinctive characteristics of the chromium oxide catalyst is the presence of an induction period during the initial period of polymerization. The duration of induction period is dependent on many factors such as catalyst preparation, activation procedures, and polymerization conditions. After the induction period, the polymerization rate increases steadily with reaction time until it reaches a stationary value. Although chromium oxide catalysts have been used for years in industrial processes, there is still a dearth of literature concerning the kinetic modeling of chromium oxide catalyzed polymerization processes. In this article, a kinetic model is developed for the chromium oxide catalyzed ethylene polymerization in gas and slurry phases. In this model, it is proposed that the reaction byproduct generated by the reduction of hexavalent chromium species to Cr2+ by ethylene poisons the active sites. With the desorption of the poison species, the deactivated sites are transformed to active sites to polymerize ethylene. The validity of the proposed model is illustrated by comparing the model calculations with the experimental data obtained from gas phase and liquid slurry polymerization experiments. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2923–2927, 2004
A honeymoon‐type adhesive for wood products based on acetoacetylated poly(vinyl alcohol) and diamines: Effect of diamines and degree of acetoacetylation
Authors: Mori Atsushi , Kitayama Takashi , Takatani Masahiro , Okamoto Tadashi
Published: January 2004

The honeymoon‐type adhesive for wood products based on acetoacetylated poly(vinyl alcohol) (AAPVA) was investigated focusing on the effect of acetoacetylation on performance, and that of amino compounds as a crosslinking agent. AAPVAs with different degrees of acetoacetylation were synthesized by the addition reaction of diketene in dimethylsulfoxide. Adhesive tests were carried out using aqueous solutions of AAPVA and six kinds of amino compounds, spread separately on test pieces of red meranti selected as the adherend. The mechanical strength of the bonded test pieces was then analyzed. It was found that the adhesive strength increased together with the degree of acetoacetylation at least until 3 h after the application of the adhesives. The degree of acetoacetylation had little effect on water resistance within the range 3.3–37.1%, and as a crosslinking agent, diamines containing primary amino groups were effective, although secondary amines and polyethyleneimine were not. It is assumed that the chemical structure of the amine influenced the crosslinking reaction at the adhesion interface. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2966–2972, 2004
Binary and ternary polymer blends containing poly(vinylidene chloride‐co‐acrylonitrile)
Authors: Hsu Wen‐Ping
Published: January 2004

Poly(vinylidene chloride‐co‐acrylonitrile) (Saran F), poly(hydroxy ether of bisphenol A) (phenoxy), poly(styrene‐co‐acrylonitrile) (PSAN), and poly(vinyl phenol) (PVPh) all have the same characteristic: miscibility with atactic poly(methyl methacrylate) (aPMMA). However, the miscibility of Saran F with the other polymer (phenoxy, PSAN, or PVPh) is not guaranteed and was thus investigated. Saran F was found to be miscible only with PSAN but not miscible with phenoxy and PVPh. Because Saran F and PVPh are not miscible, although they are both miscible with aPMMA, aPMMA can thus be used as a potential cosolvent to homogenize PVPh/Saran F. The second part of this report focused on the miscibility of a ternary blend consisting of Saran F, PVPh, and aPMMA to investigate the cosolvent effect of aPMMA. Factors affecting the miscibility were studied. The established phase diagram indicated that the ternary blends with high PVPh/Saran F weight ratio were found to be mostly immiscible. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3068–3073, 2004
Controlled radical polymerization of N‐isopropylacrylamide initiated by photofunctional 2‐(N,N‐diethyldithiocarbamyl)isobutyric acid sodium salt in aqueous medium
Authors: Ishizu Koji , Khan Ruhul A. , Furukawa Taiichi , Furo Masahito
Published: January 2004

Photopolymerizations of N‐isopropylacrylamide (NIPAAm) were carried out in water, initiated by 2‐(N,N‐diethyldithiocarbamyl)isobutyric acid sodium salt (DTCA‐Na) as water‐soluble initiator under UV irradiation. The first‐order time‐conversion plots showed slowly decreasing slopes indicating a slow decrease of the active radical concentration. The number‐average molecular weight (Mn) of the obtained poly(N‐isopropylacrylamide) (PNIPAAm) increased in direct proportion, roughly, to monomer conversion. Until ca. 60% of conversion, the polydispersity was relatively narrow (ca. 1.6). 1‐Vinyl‐2‐pyrrolidone (VP) could also be polymerized in living fashion with such PNIPAAm precursor as a macroinitiator, because PNIPAAm exhibited dithiocarbamate (DC) groups at terminal ends. It was concluded that the polymerization of NIPAAm proceeded via a controlled radical mechanism in the range ∼60% of conversion. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3233–3238, 2004
Swelling behavior and cell viability of dehydrothermally crosslinked poly(vinyl alcohol) hydrogel grafted with N‐vinyl pyrrolidone or acrylic acid using γ‐radiation
Authors: Jabbari Esmaiel , Karbasi Saeed
Published: January 2004

To improve equilibrium water content, dehydrothermally crosslinked poly(vinyl alcohol) (PVA) hydrogel was grafted with N‐vinyl pyrrolidone (NVP) or acrylic acid (AA) monomer using γ‐radiation. Swelling behavior of the grafted hydrogels was studied in phosphate‐buffered saline, and cell viability was evaluated using fibroblast cells from mouse connective tissue. Equilibrium water content of AA‐ and NVP‐grafted PVA hydrogel ranged between 40–60% and 60–80%, respectively, depending on radiation dose and monomer concentration. For maximum degree of swelling, the optimum monomer concentration and radiation dose were 20% by weight and 20 kGy, respectively. Fibroblast cells seeded on NVP‐grafted hydrogel had an extended oval morphology while those seeded on AA‐grafted PVA had a rounded spherical morphology. These results support the use of NVP for grafting PVA to increase swelling and improve cell viability. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2862–2868, 2004
FT‐IR spectroscopic investigation on the interaction between nylon 66 and lithium salts
Authors: Wu Yanjie , Xu Yizhuang , Wang Dujin , Zhao Ying , Weng Shifu , Xu Duanfu , Wu Jinguang
Published: January 2004

FT‐IR spectroscopy has been utilized to study nylon 66/lithium salt systems. The results show that coordination between nylon 66 and lithium ions brings about significant variation in the FT‐IR spectra: (1) a stronger hydrogen bond is formed in the systems; (2) the interaction induces obvious conformational changes of the nylon 66 chains. A coordination model has been proposed to rationalize the observed spectral phenomena. The interaction between amide groups and lithium ions is a feasible approach to modify the performance of nylon 66. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2869–2875, 2004
Thermal and mechanical properties of woodflour/tannin adhesive composites
Authors: Mosiewicki M. , Aranguren M. I. , Borrajo J.
Published: January 2004

Composite materials formulated with a natural polyphenolic matrix (commercial tannin adhesive made from quebracho tannin extract), pine woodflour as reinforcing material, and hexamethylenetetramine as hardener were prepared and tested. Scanning electron microscopy of fractured samples was used to analyze the efficiency of the wetting and adhesion of the filler to the surrounding matrix. Thermogravimetric analysis was used in the thermal characterization of the woodflour and the tannin extract. Flexural, compression, and dynamic‐mechanical tests were performed on composites to study the relationship of the filler content and particle size with the composite final properties. Moreover, the influence of the moisture content on the physical and mechanical properties of the different composites was analyzed. Results indicated that the mechanical properties were severely affected by the absorbed moisture. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3074–3082, 2004
Morphology investigation of transcrystallinity at polyamide 66/aramid fiber interface
Authors: He Changcheng , Dong Xia , Zhang Xiuqin , Wang Dujin , Xu Duanfu
Published: January 2004

The morphology of PA66/Kevlar‐129 fiber specimens was investigated by means of polarized optical microscopy and scanning electron microscopy. The results indicated that, at crystallization temperatures ranging from 100 to 220°C, the transcrystallinity (TC) interphase always occurs. Both the TC interphase and spherulite morphology were present under various crystallization conditions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2980–2983, 2004
Effect of surface structure on cell growth prepared by the terminal immobilization method
Authors: Sakurai Toshihiko , Mizokami Hiroshi , Furukawa Shinichi , Sakata Masayo , Kunitake Masashi , Hirayama Chyuichi , Ihara Hirotaka
Published: January 2004

Substrate effects of surface morphology and chemical structure for cell cultures prepared by molecular terminal immobilization method were studied. When we focused attention on a phenyl group as a functional moiety, the cell growth on the surface prepared by the immobilization method showed a better proliferation rate than that of a substrate prepared by the casting method. Further, from the results of mouse fibroblast L929 cell (L‐cell) growth on poly(amino acid)‐immobilized surfaces in Dulbecco's minimal essential medium containing 10% FBS, it was indicated that the amino group was more effective than the phenyl group, and that a slight difference of chemical structure had a substantial influence on cell growth. In addition, mouse bone marrow–derived Sp2/0‐Ag14 cell (Sp2/0 cell) culture in ASF‐104 serum‐free medium, poly(amino acid)‐immobilized substrates showed an almost equal proliferation rate to that in a serum‐containing medium. These results showed that effective cell growth can occur on immobilized surfaces, and that detection of a weak interaction depends on the functional groups. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3001–3008, 2004
Structural changes of 80/20 poly(vinylidene fluoride–trifluoroethylene) copolymer induced by electron irradiation
Authors: Li Weiping , Guo Shishang , Tang Yiwen , Zhao Xingzhong
Published: January 2004

The electron irradiation effect on 80/20 poly(vinylidene fluoride–trifluoroethylene) [P(VDF–TrFE)] copolymers was studied by FTIR spectra and X‐ray diffraction. Infrared spectra showed decreasing intensity of bands at 1430, 1286, 846, and 505 cm−1, the appearance and intensity increasing with irradiation doses of bands at 768, 601, and 1735 cm−1, which revealed the conformational change after irradiation. The X‐ray diffraction patterns exhibited a decrease of volume fraction of ferroelectric phase and expansion of the lattice space. The electron‐irradiated P(VDF–TrFE) films showed structural changes and polar phase to nonpolar phase transformation. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2903–2907, 2004
Study of the mechanical and electrical properties of carbon/poly(vinylidene fluoride–tetrafluoroethylene– propylene) films crosslinked with triethylenetetramine: Possible application as binder for lithium‐ion battery electrodes
Authors: Chen Zonghai , Christensen L. , Dahn J. R.
Published: January 2004

The mechanical properties of poly(vinylidene fluoride–tetrafluoroethylene–propylene) (PVDF–TFE–P) were evaluated as a function of the degree of crosslinking. Both bisphenol and triethylenetetramine (TETA) were used as crosslinkers to improve the mechanical properties of PVDF–TFE–P and carbon black–filled PVDF–TFE–P. Bisphenol was incorporated into the polymer by the manufacturer and crosslinking was achieved through additions of MgO and CaO followed by heating. Although bisphenol crosslinking improves the mechanical properties, further crosslinking was needed to obtain good extensibility under repeated deformation of carbon black/PVDF–TFE–P composites. By incorporating small amounts of 1,4‐diazabicyclo[2.2.2]octane and CaO, additions of TETA added more crosslinks in PVDF–TFE–P, leading to improved mechanical and electrical properties. The crosslinked polymer does not become brittle in typical solvents used in lithium battery electrolytes, so we believe that this highly extensible binder system may be useful for electrode materials that show large volume changes during charge–discharge cycling. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2949–2957, 2004
Mechanical and electrical properties of poly(vinylidene fluoride–tetrafluoroethylene–propylene)/Super‐S carbon black swelled in liquid solvent as an electrode binder for lithium‐ion batteries
Authors: Chen Zonghai , Christensen L. , Dahn J. R.
Published: January 2004

The mechanical and electrical properties of poly(vinylidene fluoride–tetrafluoroethylene–propylene) (PVDF–TFE–P) and carbon black–filled PVDF–TFE–P composites were investigated. The carbon black was used for its electrolyte absorption properties in addition to boosting the conductivity. This elastomeric binder system may have application to tin‐ or silicon‐based electrode materials for Li‐ion batteries, which undergo huge volumetric changes during charge/discharge cycling. The mechanical and electrical properties were measured while film samples were immersed in a liquid solvent (ethylene carbonate : diethyl carbonate 1 : 2) commonly used in the battery electrolyte. Uncrosslinked PVDF–TFE–P uptakes about 140% solvent by mass and swells significantly. The amount of solvent absorbed can be reduced and the mechanical properties improved by crosslinking the polymer. Two crosslinking recipes, based on bisphenol and triethylenetetramine (TETA), were investigated carefully. Compared to the bisphenol‐based crosslinking recipe, the proposed TETA‐based crosslinking recipe gave films with a higher degree of crosslinking and better mechanical properties. The TETA‐crosslinked composites had very good mechanical and electrical reversibility even during cyclic deformation to 100% strain. The cycling results of amorphous Si0.64Sn0.36 electrodes show that the capacity retention of the electrodes can be significantly improved by using the proposed elastomeric binder. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2958–2965, 2004
Thermomechanical analysis of the biaxially drawn ultrahigh molecular weight polyethylene‐reinforced polyether polyurethane
Authors: Tang Zheng Gui , Teoh Swee Hin
Published: January 2004

To understand the thermal fusion and interaction of porous polyurethane composites, the thermomechanical profiles of the heat‐compacted composites were described and explained in line with differential scanning calorimetry analysis, FTIR‐ATR interpretation, and morphological observations of the oriented ultrahigh molecular weight polyethylene (UHMWPE) under polarized light transmission. The results indicated that the as‐cast polyurethane composites are porous and can be consolidated in heat compaction. The consolidated polyurethane composites displayed no thermal contraction in the thermomechanical analysis. Two polyurethane materials, Toyobo TM5 and Tecoflex 80A, were selected for the study. The differences between aromatic and aliphatic polyurethane composites were significant. Aromatic polyurethane composites exhibited characteristic thermal fusion, resulting in a uniform heat‐compacted specimen that synergized the thermomechanical advantages of the polyurethane. This thermal fusion led to constraints of UHMWPE and recrystallization of both UHMWPE and polyurethane. The synergized polyurethane composite demonstrated superior resistance to thermal degradation, observed in both the individual UHMWPE and aromatic polyurethane. Thermomechanical analysis supported the recommendation of using the specific heat compaction at 115°C. This process rendered the aromatic polyurethane composite of highly thermomechanical stability, in agreement with previous findings related to optical transparency and tensile properties. The thermomechanical responses of the composite also provided detailed information about the differences between two samples of similar optical transparency and therefore led to the definition of the synergistic structural composite, a void‐free composite with clear evidence. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3088–3095, 2004
Interaction between wood and polyvinyl acetate glue studied with dynamic mechanical analysis and scanning electron microscopy
Authors: Backman A. C. , Lindberg K. A. H.
Published: January 2004

The long‐term properties of bonds are those that are of special interest. To achieve good bonds, the wood polymers and the adhering polymers must be compatible. This paper describes studies of the interaction of wood (Pinus sylvestris) with commercial polyvinyl acetate (PVAc) glue, polymethylmethacrylate (PMMA), and a more hydrophilic acrylate. Interaction was studied with a dynamic mechanical thermal analyzer (DMTA) operating in tensile mode in the tangential direction of wood. DMTA results were correlated with scanning electron microscopy (SEM) fractography studies of adhesion between polymers and wood on a cell wall level. The hypothesis put forward is that a good adhesion on the cell wall level results in a decrease in the glass transition temperature (Tg) measured with DMTA. A decrease in Tg for the hydrophilic acrylate was shown when it was impregnated in wood. The decrease of Tg was correlated with good adhesion to wood on the cell wall level. For PVAc and PMMA no decrease in Tg was measured when glued or impregnated in wood. SEM study also showed that the adhesion on a cell wall level was poor. The results show that DMTA can be a useful technique to study adhesion between wood and glue on a molecular level. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3009–3015, 2004
Effect of acrylate constituent units on the adhesion of polyacrylate sizes to fiber substrates
Authors: Zhu Zhifeng , Qiao Zhiyong , Kang Cuizhen , Li Yuehua
Published: January 2004

The influences of chemical structure of (meth)acrylate monomers, including the carbon atom number of alkyl ester groups and the α‐methyl group, on the adhesion of polyacrylate sizes to all‐polyester, pure cotton, and polyester/cotton blend fiber substrates are investigated by using an impregnated roving method for warp sizing. The adhesion is evaluated in terms of the bonding strength, breaking extension, and work of break of a slightly sized roving. The polyacrylate sizes are prepared through free radical copolymerization of (meth)acrylates with acrylic acid in ethanol. It was found that the adhesion is strongly affected by the structure of acrylate monomers. The adhesion enhances with increasing the carbon atom number of alkyl ester side chains of acrylates, whether or not it is an acrylate or a methacrylate. The α‐methyl does not favor the adhesion to polyester fibers, but favor to polyester/cotton blend fibers. Moreover, the molar ratio of butyl acrylate to acrylic acid is also considered. Excessively lowering the amount of acrylate or acrylic acid damages the adhesion. A favorable molar ratio of butyl acrylate to acrylic acid is found to be about 60 : 40. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3016–3022, 2004
Diffusion and sorption of benzene vapor through polybutadiene‐, polybutadiene/styrene‐, and polybutadiene/acrylonitrile‐based polyurethanes
Authors: Yang Yurun , Huang Yongmin , Chen Yonglin , Wang Dening , Liu Honglai , Hu Chunpu
Published: January 2004

A series of polyurethane (PU) films made from toluene diisocyanate (TDI), 1,4‐butanediol (BDO), and hydroxyl‐terminated polybutadiene (HTPB), hydroxyl terminated polybutadiene/styrene (HTBS), or hydroxyl terminated polybutadiene/acrylonitrile (HTBN) was synthesized by solution polymerization. The absorption of benzene vapor was found mainly in the soft phase. The equilibrium adsorption (M∞) was reduced with increasing hard segment content for all the PUs. The values of M∞ were in the sequence of HTBN‐PUs > HTBS‐PUs > HTPB‐PUs, which could be explained by the different interaction parameters between soft segments and benzene. The HTBN‐PU film showed the lowest degree of phase segregation and had more hard segments intermixed in the soft phase, restricting the movement of soft segments, and therefore resulted to non‐Fickian behavior, while the HTPB‐PU is antithetical. FTIR and atomic force microscopy were utilized to identify the hydrogen bonding behavior and morphology change of the PU films before and after the absorption of benzene vapor. The tensile strength of the HTBN‐PUs showed a greater decrease than that of HTBS‐PUs and HTPB‐PUs after absorbing benzene vapor. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2984–2991, 2004
Structure, mechanical, and thermal behavior of nylon 6‐polyisoprene block copolymers obtained via anionic polymerization
Authors: Mateva R. , Filyanova R. , Dimitrov R. , Velichkova R.
Published: January 2004

The structure and physicomechanical properties of nylon 6 (N‐6) modified with polyethylene oxide–polyisoprene–polyethylene oxide (PEO‐PI‐PEO) copolymers via activated anionic polymerization have been investigated by using differential scanning calorimetry (DSC), wide‐angle X‐ray diffraction (WAXD), thermogravimetric analysis (TGA), dynamic mechanical analysis (DTMA), and by optical microscopy. This study deals with the influence that the N‐6/PI ratio and the length of the PI segments have on the physicomechanical behavior, thermal stability, and the structural changes of the block copolymers. Literature does not report on previous investigations of this kind. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3251–3258, 2004
Effect of F/P and OH/P molar ratios and condensation viscosity on the structure of phenol‐formaldehyde resol resins for overlays—A statistical study
Authors: Holopainen Timo , Alvila Leila , Savolainen Pirkko , Pakkanen Tuula T.
Published: January 2004

A two‐level full factorial experimental design with three variables, formaldehyde‐to‐phenol (F/P) molar ratio, hydroxyl‐to‐phenol (OH/P) molar ratio, and condensation viscosity was implemented to determine the effect of the variables on the structure of phenol‐formaldehyde resol resins for paper overlay impregnation. Ten resins were prepared with F/P molar ratios between 1.9 and 2.3, OH/P molar ratios between 0.09 and 0.13, and condensation viscosities between 60 and 180 mPa s. The effect of these three independent variables on the chemical structure was analyzed by 13C‐NMR spectroscopy, on the molecular weight distribution by gel permeation chromatography, and on the reactivity by differential scanning calorimetry. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2942–2948, 2004
Hydrogenation of cis‐1,4‐polyisoprene catalyzed by Ru(CHCH(Ph))Cl(CO)(PCy3)2
Authors: Tangthongkul R. , Prasassarakich P. , McManus N. T. , Rempel G. L.
Published: January 2004

Hydrogenation is a useful method which has been used to improve oxidative and thermal degradation resistance of diene‐based polymers. The quantitative hydrogenation of cis‐1,4‐polyisoprene which leads to an alternating ethylene–propylene copolymer was studied in the present investigation. To examine the influence of key factors on the reaction, such as catalyst concentration, polymer concentration, hydrogen pressure, and temperature, a detailed study of the hydrogenation of cis‐1,4‐polyisoprene catalyzed by the Ru complex, Ru(CHCH(Ph))Cl(CO)(PCy3)2 was carried out by monitoring the amount of hydrogen consumed. Infrared and 1H‐NMR spectroscopic measurements confirmed the final degree of hydrogenation. The hydrogenation of cis‐1,4‐polyisoprene followed pseudo‐first‐order kinetics in double‐bond concentration up to high conversions of double bond, under all sets of conditions studied. The kinetic results suggested a first‐order behavior with respect to total catalyst concentration as well as with respect to hydrogen pressure. The apparent activation energy for the hydrogenation process, obtained from an Arrhenius plot, was 51.1 kJ mol−1 over the temperature range of 130 to 180°C. Mechanistic aspects of the catalytic process are discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3259–3273, 2004
Synthesis and characteristics of polyelectrolyte complexes composed of chitosan and hyaluronic acid
Authors: Kim Seon Jeong , Shin Su Ryon , Lee Kyu Back , Park Yong Doo , Kim Sun I.
Published: January 2004

Polyelectrolyte complexes (PEC) composed of various weight ratios of chitosan and hyaluronic acid (HA) were prepared. The PECs were formed by a reaction of the oppositely charged polymers. The characterizations of the PEC films were investigated by using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The PECs were found to swell rapidly, reaching equilibrium within 30 min, and exhibited relatively high swelling ratios of 250–325% at room temperature. The swelling ratio increased when the pH of the buffer was below pH 6, as a result of the dissociation of the ionic bonds, and with increments of temperature. Therefore, the swelling ratios of the films were pH and temperature dependent. DSC was used to determine the amount of free water in the PEC films, which increased with increasing chitosan content. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2908–2913, 2004
Radiation crosslinking and sorption properties of hydrogels based on 1‐vinyl‐2‐pyrrolidone, hydroxyethyl methacrylate, and their copolymers
Authors: Nizam El‐Din Horia M. M. , Maziad Nabila A. , El‐Naggar Abdel Wahab M.
Published: January 2004

This work has been concerned with the synthesis of the hydrogels of poly (vinyl pyrrolidone) (NVP), poly (hydroxy ethylmethacrylate) (HEMA), and their copolymer under the effect of gamma radiation in the presence of N,N‐methylenebisacryl‐amide (MBAm) as a crosslinking agent. The effect of the different factors that may affect the gelation and yield product, such as solvent composition and irradiation dose, was investigated. The formed hydrogels were characterized in terms of swelling in water and different organic solvents, X‐ray diffraction (XRD), and IR spectroscopic analysis. The sorption capability of these hydrogels towards some commercial basic and acid dyesstuffs was also studied. The results showed that a solvent mixture composed of equal contents of water and methanol is the most suitable to afford the minimum sol fraction and the highest yield product at a minimal irradiation dose of 10 kGy. It was observed that NVP hydrogel displayed the highest swelling in water, alcohols, and dimethyformamide of ∼1300% and a lower tendency to swell in nonpolar solvents. The results showed that HEMA hydrogel has a high affinity to absorb basic dyes while NVP has a tendency for acid dyes. Also, the sorption of either the basic or acid dyes by the different hydrogels was found to greatly depend on the concentration of dye in solution and the mass of the used hydrogel. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3274–3280, 2004
Microwave‐assisted and conventional polycondensation reaction of optically active N,N′‐(4,4′‐sulphonediphthaloyl)‐bis‐L‐leucine diacid chloride with aromatic diamines
Authors: Mallakpour Shadpour , Kowsari Elaheh
Published: January 2004

3,3′,4,4′‐Diphenylsulfonetetracarboxylic dianhydride (1) was reacted with L‐leucine (2) in acetic acid and the resulting imide‐acid (3) was obtained in high yield. The diacid chloride (4) was prepared from diacid derivative (3) by reaction with thionyl chloride. The polycondensation reaction of diacid chloride (4) with several aromatic diamines such as 4,4′‐sulfonyldianiline (5a), 4,4′‐diaminodiphenyl methane (5b), 4,4′‐diaminodiphenylether (5c), p‐phenylenediamine (5d), m‐phenylenediamine (5e), 2,4‐diaminotoluene (5f), and 1,5‐diaminonaphthalene (5g) was developed by using a domestic microwave oven in the presence of a small amount of a polar organic medium such as o‐cresol. The polymerization reactions were also performed under two conventional methods: low temperature solution polycondensation in the presence of trimethylsilyl chloride, and a short period reflux conditions. A series of optically active poly(amide‐imide)s with inherent viscosity of 0.25–0.42 dL/g were obtained with high yield. All of the above polymers were fully characterized by IR, elemental analyses, and specific rotation techniques. Some structural characterizations and physical properties of these optically active poly (amide‐imide) s are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2992–3000, 2004
Swelling characterization of the semiinterpenetrating polymer network hydrogels composed of chitosan and poly(diallyldimethylammonium chloride)
Authors: Kim Seon Jeong , Yoon Seoung Gil , Kim In Young , Kim Sun I.
Published: January 2004

Temperature‐ and pH‐responsive semiinterpenetrating polymer network (SIPN) hydrogels, constructed with chitosan (CS) and poly(diallyldimethylammonium chloride) (PDADMAC), were studied. The characterizations of the IPN hydrogels were investigated by fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), and swelling tests, under various conditions. CS/PDADMAC SIPN hydrogels exhibited a relatively high swelling ratio, in the range of 248–462%, at 25°C. The swelling ratio of CS/PDADMAC IPN hydrogels are pH, temperature, and ionic concentration dependent. DSC was used for the quantitative determination of the amounts of freezing and nonfreezing water. The amount of free water increased with increasing PDADMAC content in the IPN hydrogels. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2876–2880, 2004
Segmented MDI/HMDI‐based polyurethanes with lowered flammability
Authors: Pielichowski Krzysztof , Słotwińska Dominika , Dziwiński Euzebiusz
Published: January 2004

A series of segmented polyurethanes (PUs) based on 4,4′‐diphenylmethane diisocyanate and 1,6‐hexamethylenediisocyanate; polyoxypropylenediol (POPD); and low‐molecular chain extenders, 1,2‐propanediol or 3‐chloro‐1,2‐propanediol was obtained by solution polymerization and characterized by GPC and microscopic methods. Spherical aggregates with diameter of about 200 nm, arranged in a quasi‐linear mode, were observed by SEM technique; further investigations by the TEM method revealed hard‐segment domains of longitudinal shape, with length of about 5–10 nm, showing some features of the arrangement along a “director” axis. The process of thermal decomposition was monitored by thermogravimetric analysis in both dynamic and isothermal mode; to gain a deeper look into the mechanism of decomposition, kinetic analysis was performed. First, isoconversional methods showed a multistep decomposition route, as the value of (apparent) energy of activation changes from about 150 kJ/mol in the first step up to about 350 kJ/mol in the third step, which corresponds to the energy of dissociation of CC bonds and leads to a char (carbonaceous) residue. Further calculations by means of the linear regression method revealed that kinetic model functions describing the degradation process of PU that does not contain chlorine were Bna → An → Fn, whereby for chlorine‐containing polyurethanes the CnB → An → An model was applied as best fit. Volatile products were investigated by pyrolysis–gas chromatography/mass spectrometry method at 770°C; the low molecular weight decomposition products, which were identified, indicate that the depolymerization process, yielding mainly diols and isocyanates through breakage of urethane bonds, prevailed during the thermal treatment under pyrolytic conditions. Finally, the mechanism of thermal degradation of modified polyurethanes with lowered flammability was proposed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3214–3224, 2004
Strain–tensor components, crystallite shape, and their effects on crystalline structure in silk I
Authors: Sangappa  , Okuyama Kenji , Somashekar R.
Published: January 2004

By using the X‐ray powder data obtained from Bombyx mori silk fibroin in silk I modification, we have estimated the strains by using profiles of several (hkl) reflections observed in the fibroin. For this purpose, we have used line profile simulation and matching with the experimental, on the basis of a paracrystalline one‐dimensional Hosemann's model proposed earlier. The shape of the crystallite and size along different directions in the fibroin have also been estimated and presented here. From these results, the strain tensor has been computed by using the approach given by Wilke and Martis. The effect of these strains on the molecular arrangement within the crystal structure and the nature of changes in the chain within the unit cell which participates in inducing the intrinsic strain during the formation of the fiber (silkII) are reported here. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3045–3053, 2004
Application of concentrated emulsion polymerization for preparation of ion‐exchange chromatography columns
Authors: Baharvand H. , Rabiee A.
Published: January 2004

Concentrated inverse emulsion polymerization was used for making chromatography columns [based on crosslinked polystyrene divinylbenzene (PS–DVB)] with pore sizes less than 10 μm. For application of these columns in ion‐exchange chromatography, the sulfonation process was performed by concentrated sulfuric acid. According to X‐ray fluorescence analysis and ASTM D2187‐94 standard test method, the total capacity of resins (sulfonated PS–DVB) increased with increasing time. To obtain high‐capacity resins, the sulfonation process was carried out over two steps. The optimum sulfonation time for the first and second sulfonation steps was 24 and 48 h, respectively. By increasing the DVB content, the capacity of resins passed through a maximum; thus the optimum amount of DVB, as crosslinking agent in the sulfonation process, was 22.5%. The structure of columns was analyzed by scanning electron microscopy (SEM). SEM evaluations showed that the porous structure of PS–DVB resin was maintained intact after the sulfonation steps. According to DSC–thermal gravimetry thermograms, it was confirmed that the residual monomer concentration after polymerization process was negligible. Also, the PS–DVB resins exhibit thermal stability up to 300°C and this quantity would increase with increasing amount of DVB weight percentage. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2973–2979, 2004
Infiltration of uncured elastomers into silica agglomerates
Authors: Astruc Marianne , Collin Véronique , Rusch Steven , Navard Patrick , Peuvrel‐Disdier Edith
Published: January 2004

The degree of impregnation of an agglomerate by the suspending matrix is an important parameter because it influences the agglomerate cohesion and thus has a direct effect on dispersion mechanisms. Penetration kinetics reported in the literature were only measured in Newtonian or not very elastic matrices, although one of the main applications is the dispersion of porous filler in elastomers. The aim of this article is to study the infiltration of porous silica agglomerates by uncured elastomers using optical microscopy. The application of the model of Bohin (infiltration of a Newtonian fluid into a porous sphere) is discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3292–3300, 2004
Laser light‐scattering molecular weight analysis of a poly(fluoro acrylate)
Authors: Meyer Andrew , Jones Nick , Lyle Scott , Venkataramani Shiv , Clark John , Kranbuehl David
Published: January 2004

Two leading macromolecular characterization techniques were employed for analysis of a unique, difficult to dissolve fluorinated polymer system (PFA), Poly(N‐methyl perfluoroocytyl sulfonamido ethyl acrylate). Multiangle Laser Light Scattering (MALLS) and Viscosity–Right Angle Laser Light Scattering (RALLS) were used to measure the weight‐average molecular weight and molecular size‐radius using the solvent HFIP, 1,1,1,3,3,3‐hexafluoroisopropanol. HFIP is shown to be an excellent solvent for light scattering measurements on the PFA as well as on Polyamide‐11 and Polymethyl methacrylate. It is shown that the Viscosity‐RALLS approach gives results that differ from the MALLS system due to the assumptions used. It is also shown that the addition of salt does affect the molecular weight dependence of the radius of gyration but not the value of Mw. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3447–3454, 2004
The role of ordered block copolymer morphology in the performance of organic/inorganic photovoltaic devices
Authors: Gratt Jason A. , Cohen Robert E.
Published: January 2004

A triblock copolymer consisting of hole‐transport, electron‐transport, and nanocluster‐binding moieties was used in the fabrication of photovoltaic test devices. Depending on the casting solvent used in the device fabrication process, the morphology of the block copolymer in the devices was either an ordered, perpendicular cylindrical phase or a uniformly mixed homogeneous material. The photovoltaic action spectra of these two device types revealed clearly that the charge collection efficiency was influenced favorably by the microphase separation of the ordered system. Underlying mechanisms for these observations are discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3362–3368, 2004