bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of reaction conditions on the grafting of 2‐(dimethylamino)ethyl methacrylate onto hydrocarbon substrates
Authors: Shing J. B. Wong , Baker W. E. , Russell K. E. , Whitney R. A. 
Published: April 2003

AbstractThe grafting of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) onto two model hydrocarbons, squalane and n‐eicosane, and to linear low density polyethylene (LLDPE) has been investigated. The results of the study indicate that a high reaction temperature, 160°C, and a low concentration of monomer, less than 0.3 M, are optimum conditions for the grafting reaction. Reaction products, which consisted of grafted hydrocarbons and poly(DMAEMA), were separated by solvent extraction and vacuum distillation; samples were then analyzed by NMR and FTIR spectroscopy and size exclusion chromatography. 1H‐NMR spectroscopy indicates that grafted squalane contained approximately 6 DMAEMA units per squalane residue. 1H‐ and 13C‐NMR and molecular weight studies strongly suggest that the grafts onto the model hydrocarbons consist of single DMAEMA units. Results of the melt grafting of DMAEMA onto LLDPE show that the grafting efficiency and degree of grafting are substantially lower than were expected from the model system. © 1994 John Wiley & Sons, Inc.
Acyloin condensation in aqueous system by durable polymer‐supported thiazolium salt catalysts
Authors: Yamashita K. , Osaki T. , Sasaki K. , Yokota H. , Oshima N. , Nango M. , Tsuda K. 
Published: April 2003

AbstractWe characterized three low‐molecular‐weight thiazolium salt analogues: N‐methyl‐5‐(2′‐benzyloxyethyl)‐4‐methylthiazolium iodide (MBMTI), N‐methyl‐4‐phenylthiazolium iodide (MPTI), and N‐methylbenzothiazolium iodide (MBTI). MBMTI, having high‐electron density on the thiezolium ring, was found to be a durable thiazolium salt in buffer solution. Then, the polymer‐supported thiazolium salt catalyst having MBMTI structure as a catalytic site for acyloin condensation was prepared by the polymerization of the corresponding thiazole monomer and the following quaternization. The polymer catalyst had excellent catalytic activity even in buffer solution, while the corresponding low molecular weight catalyst did not show any activity in aqueous system. Furthermore, the durable polymer catalyst could be reused under the aqueous condition. © 1994 John Wiley & Sons, Inc.
Synthesis and properties of superconductors prepared from ethylenediaminetetraacetic acid (EDTA)‐ethylenediamine (ED) polyamide YBC chelate
Authors: Maeda Shigeru , Tsurusaki Yoshiyuki , Tachiyama Yoshiyuki , Naka Kensuke , Ohki Akira , Ohgushi Tetsuya , Takeshita Toshio 
Published: April 2003

AbstractSingle‐phase Y1Ba2Cu3O7‐x has been synthesized by a polymer‐metal chelate precursor technique. Ethylenediaminetetraacetic acid (EDTA)‐ethylenediamine (ED) polyamide was used as chelating polymer for Y, Ba, and Cu. The titration curves of the polymer in the absence and presence of each metal ion showed the chelate formations. The polymer was dissolved in water and the metal nitrates of Y, Ba, and Cu (1:2:3 in mole ratio) were stoichiometrically added to form a homogeneous molecular complex. The clear polymermetal chealate film was obtained by removal of the solvent without phase separation. This precursor was dried, calcined, and sintered to develop the superconducting (1,2,3) phase. The 1,2,3 phase produced was found to be pure according to x‐ray diffraction pattern and it possessed good superconducting properties, i.e., the onset of superconductivity was seen at 90.0 K and the resistance rapidly decreased with decreasing temperature, reaching substantially zero at 88.6 K. Scanning electron microscope (SEM) and face and point analyses by electron probe microanalysis (EPMA) showed that Y, Ba, and Cu elements were uniformly dispersed at least micron order. © 1994 John Wiley & Sons, Inc.
Penetration of plasma surface modification. I. Cf4 and C2F4 glow discharge plasmas
Authors: Yasuda T. , Okuno T. , Miyama M. , Yasuda H. 
Published: April 2003

AbstractPlasma treatment of a polymeric surface could involve at least three major mechanisms: (1) direct interaction of reactive species in the low‐temperature plasma state with the surface (line of sight irradiation effect), and (2) chemical reactions of plasma‐induced reactive species with the surface, and (3) reactions among reactive species and the surface (plasma polymerization). The first and the third effects are considered to be limited to the surfaces which directly contact with plasma (glow). The second effect is not limited to the surfaces that contact with plasma state but can penetrate beyond the plasma zone by diffusion. Using an assembly of fibers, of which only the top layer contacts with plasma (glow), the penetration of chemical changes caused by plasma exposure was investigated. Results indicate that the fluorination effect (incorporation of fluorine‐containing moieties on the surface of polymeric substrate) penetrates through a considerable thickness of the assembly of fibers, depending on the porosity (gas permeability) of the system. Chemical reactions of plasma‐induced (chemically) reactive but nonpolymerizing species with the substrate fibers seems to predominate. The direct interactions of energetic species, such as ions, electrons, and electronically excited species, with polymeric surfaces seems to play relatively minor roles in the plasma treatment investigated. The major role of plasma, in this case, seems to be creating such chemically reactive species. © 1994 John Wiley & Sons, Inc.
Synthesis of thiol chelating resins and their adsorption properties toward heavy metal ions
Authors: Lezzi Alessandro , Cobianco Sandra , Roggero Arnaldo 
Published: April 2003

AbstractA series of chelating resins, derived from a macroreticular styrene‐divinylbenzene (2%) copolymer beads grafted with various poly(ethylene glycols) HO(CH2CH2O)nH(n = 0, 4, 9, 13) and containing thiol groups as chelating functions, have been synthesized in a three‐step reaction sequence. The structure of the functionalized resins was confirmed by IR spectrophotometry, elemental analysis, and differential scanning calorimetry. The complexation behavior of these thiol resins was investigated towards Hg(II), Cu(II), and Pb(II) ions in aqueous solution by a batch equilibration technique. The influence of pH on adsorption capacity was also examined. The adsorption values for metal ions' intake followed the order Hg(II) > Cu(II) > Pb(II). The affinity of these polymers towards Hg(II) ions was so high that the total mercury level in the liquid decreased from 20 ppm to below 10 ppb after 2 h of treatment. Polymers can be regenerated by washing with a solution of hydrochloric acid (6N) and 10% by weight of an aqueous solution of thiourea. © 1994 John Wiley & Sons, Inc.
Thermotropic copolyamides from triethyleneglycol bis(4‐carboxyphenyl)ether, aromatic diamines, and p‐aminobenzoic acid modified by the monomer sequences in the copolyamides
Authors: Zhang Wen Xiong , Higashi Fukuji 
Published: April 2003

AbstractCopolycondensations of triethyleneglycol bis(4‐carboxyphenyl)ether (PEG3), p‐amino‐benzoic acid (PABA), and p‐phenylenediamine (PPD) were studied in order to examine the effect of monomer sequences in the copolyamides upon the transition temperatures of the resulting copolymers. Random copolymerization of these monomers resulted in the copolymers exhibiting a nematic mesophase in a wide range of PABA content. On the other hand, the sequential copolymers composed of PABA/PPD = 1/1 and 2/1, which were prepared from 4,4′‐diaminobenzanilide (DABA) and N,N′‐bis(4‐aminobenzoyl)‐p‐phenylenediamine (BAB‐PPD), respectively, did not show a mesophase. The copolymers of a diamine combination of DABA and PPD exhibited a nematic mesophase, despite the lack of a mesophase for each homopolymer. The combinations of DABA and other diamines were also examined. © 1994 John Wiley & Sons, Inc.
Cation exchange membranes by pre‐irradiation grafting of styrene into FEP films. I. Influence of synthesis conditions
Authors: Gupta Bhuvanesh , Büchi Felix N. , Scherer Günther G. 
Published: April 2003

AbstractGamma radiation‐induced grafting of styrene into FEP films was investigated by the pre‐irradiation method. The degree of grafting was found to be strongly dependent on the synthesis conditions, such as radiation dose, monomer concentration, crosslinker, temperature, and film thickness. The order of dependence of the rate of grafting on pre‐irradiation dose and monomer concentration was found to be 0.64 and 1.90, respectively. The activation energy for the grafting in the temperature range of 50–80°C was determined to be 27.9 kJ/mol. A negative first order dependence of grafting on film thickness was observed. The results suggest that the initial grafting takes place at the film surface and proceeds to the middle by progressive diffusion of monomer through the polystyrene grafted layers. © 1994 John Wiley & Sons, Inc.
Quinone‐amine polymers. XV. Syntheses and characterization of high‐temperature resistant poly(arylamino‐quinone)s
Authors: Reddy T. Ashok , Macaione D. , Erhan S. 
Published: April 2003

AbstractSeveral poly(arylamino‐quinone)s (PAAQs) were prepared by the conventional solution polymerization of p‐benzoquinone with various aromatic diamines in tetrahydrofuran. Polymers prepared by this method were found to be more soluble in many organic solvents compared to the PAAQs prepared by other reported methods. The poly(arylamino‐quinone)s were obtained in 82.3–94.5% yield and had inherent viscosities in the range of 0.073–0.251 dL/g. Among the PAAQs, the polymer prepared from p‐benzoquinone and 1,3‐bis(3‐aminophenoxy)benzene (APB) had demonstrated exceptionally good solubility and thermal stability. © 1994 John Wiley & Sons, Inc.
Basic structure–property behavior of polyurethane cationomers
Authors: Lee Jong Cheol , Kim Byung Kyu 
Published: April 2003

AbstractPolyurethane (PU) cationomers were synthesized from polytetramethylene adipate glycol (PTAd), isophorone diisocyanate (IPDI), and N‐methyl diethanolamine (MDEA) according to a prepolymer mixing process. Basic structure‐property behavior of the emulsion (obtained by adding water to the ionomer solution) and emulsion cast film was studied with regard to the molecular weight (Mn) of PTAd, MDEA content, degree of neutralization, and extender functionality. Particle size decreased asymptotically with increasing Mn of PTAd due to the increased chain flexibility, and with the degree of neutralization due to the increased hydrophilicity of the PU. Emulsion viscosity generally showed the opposite tendency with particle size dependence. The major transition temperature, corresponding to the glass transition (Tg) of phase mixed PU or hard segment‐rich phase of the PU monotonically increased with MDEA content, degree of neutralization, and with increasing extender functionality. However, with increasing Mn of PTAd, Tg first decreased (Mn = 1000) and then increased (Mn = 1500, 2000), due respectively to the increased hard fraction of phase mixed PU, and soft segment crystallization. Tensile strength increased and elongation at break decreased with MDEA content, degree of neutralization, and extender functionality. © 1994 John Wiley & Sons, Inc.
Polymeric networks by the cationic crosslinking reaction of poly(allenyl ether)s having oligo(oxyethylene) moieties in the side chain
Authors: Aggour Yassin A. , Tomita Ikuyoshi , Endo Takeshi 
Published: April 2003

AbstractCationic crosslinking reactions of poly(allenyl ether)s having oligo(oxyethylene) moieties prepared by the radical polymerization of the corresponding allenyl ethers were carried out under some varied reaction conditions. For instance, a crosslinked polymer was obtained in 82% yield by the treatment of poly(ethylene glycol methyl allenyl ether) (1a) with 1.2 mol% of BF3·OEt2 (2) under high concentration in dichloromethane (46 wt %). The gels obtained showed good swelling properties in water, alcohols, and polar organic solvents such as dichloromethane. In particular, the degrees of swelling of these gels in aqueous sodium chloride (1M) were quite similar to those in ion‐free water, indicating that these gels served as nonionic hydrogels. © 1994 John Wiley & Sons, Inc.
Polymeric phosphonium salts as a novel class of cationic biocides. IX. Effect of side‐chain length between main chain and active group on antibacterial activity
Authors: Kanazawa Akihiko , Ikeda Tomiki , Endo Takeshi 
Published: April 2003

AbstractPolymeric phosphonium salts with different side‐chain length between the main chain and the active group, poly[4‐2‐tributyl‐phosphonioethyl)styrene chloride‐co‐4‐(2‐chloroethyl)styrene] and poly[4‐(3‐tributylphosphoniopropyl)styrene chloride‐co‐4‐(3‐chloropropyl)styrene], were prepared and their antibacterial activities against Staphylococcus aureus and Escherichia coli were examined by the viable cell counting method in sterile distilled water. The antibacterial activity was found to decrease as the side‐chain length increased. The most significant finding is a peculiar concentration dependence of the antibacterial activity, which demonstrated the presence of an optimal concentration. The observed specific effects of the side chain length and the concentration on the antibacterial activity seem to be ascribed to the state of aggregation of the polycationic biocides in aqueous solution. © 1994 John Wiley & Sons, Inc.
Kinetics of polyesterification: Effect of diol chain length
Authors: Uphade B. S. , Patil P. S. , Pandit S. B. , Rajan C. R. , Nadkarni V. M. 
Published: April 2003

AbstractKinetics of polyesterification of maleic anhydride with polyethylene glycol (PEG) of varying molecular weights have been evaluated. The investigations have been carried out by employing heating cycles comparable to those employed in industrial processes and under nonisothermal conditions. The rate of reaction was found to decrease with increase in the chain length of the polyether. The energy of activation was estimated as 26.91, 40.25, and 47.30 Kcal/mol for PEG of molecular weights 200, 300, and 400, respectively. © 1994 John Wiley & Sons, Inc.
Phase behavior of cyclic siloxane‐based liquid crystalline compounds
Authors: Gresham K. D. , McHugh C. M. , Bunning T. J. , Crane R. L. , Klei H. E. , Samulski E. T. 
Published: April 2003

AbstractA series of 24 cyclic siloxane‐based liquid crystalline compounds was synthesized using conventional hydrosilation chemistry. Variables examined included ring size, spacer group length, and type and composition of pendant mesogeric groups. Both pentamethylhydro‐ and tetramethylhydrosiloxane rings were reacted with mesogens based on cholesterol, biphenyl, or equimolar mixtures of both. Four different length spacer groups containing terminal vinyl groups were used to attach the mesogens to the cyclic siloxane core. The thermotropic liquid crystalline phase behavior was studied using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). A lengthening of spacer groups resulted in lower crystallization temperatures for the biphenyl‐based compounds and lower glass transition temperatures for the cholesterol‐ and mixed mesogen‐based compounds. The tetramethyl ring derivatives exhibited higher glass transition or crystallization temperatures than their pentamethyl counterparts. Biphenyl‐based compounds exhibited low temperature crystalline phases while the cholesterol‐based compounds exhibited low temperature glassy phases. © 1994 John Wiley & Sons, Inc.
Polymerization of N‐alkyl‐substituted itaconimides and N‐(alkyl‐substituted phenyl)itaconimides and characterization of the resulting polymers
Authors: Watanabe Hiroyuki , Matsumoto Akikazu , Otsu Takayuki 
Published: April 2003

AbstractN‐alkyl‐substituted itaconimides (RII) and N‐(alkyl‐substituted phenyl)itaconimides (RPhII) with various alkyl substituents were prepared and polymerized in the presence of a radical or anionic initiator to give high molecular weight polymers in high yields. The effects of the alkyl substituents on the polymerization reactivities were investigated. It has been revealed that RII and RPhII have the highest polymerization reactivity compared with other itaconic and citraconic derivatives including dialkyl itaconates and citraconimides. The structure and some properties of poly(RII) and poly(RPhII) were examined. These polymers were found to have excellent thermal stability, better than poly (dialkyl itaconate)s. © 1994 John Wiley & Sons, Inc.
Radical polymerization of N‐substituted itaconamic esters and itaconamides
Authors: Watanabe Hiroyuki , Matsumoto Akikazu , Otsu Takayuki 
Published: April 2003

AbstractTwo kinds of itaconamic esters, α‐substituted acrylate derivatives (IAE‐I) and α‐substituted acrylamide derivatives (IAE‐II), as well as itaconamides (IAm) were prepared and polymerized with a radical initiator. It has been revealed that N,N‐disubstituted IAE‐I as an acrylate is more reactive in polymerization than N,N‐disubstituted IAE‐II as an acrylamide and that N,N′‐dialkyl substituted IAm homopolymerizes but N,N,N′,N′;‐tetraalkyl substituted one does not. In radical copolymerization with styrene, IAE‐I showed a higher polymerization reactivity than IAE‐II. The effects of the N‐substituents on the polymerization reactivity were discussed on the basis of conformation of the monomers. The polymers obtained were also characterized. © 1994 John Wiley & Sons, Inc.
Synthesis and properties of poly(arylene ether phenyl‐s‐triazine)s
Authors: Matsuo Shigeru 
Published: April 2003

AbstractA series of new poly(arylene ether phenyl‐s‐triazine)s was prepared by the nucleophilic aromatic substitution polymerization of the potassium salt of bisphenols with 2,4‐bis (halophenyl)‐6‐phenyl‐s‐triazine in N‐methyl‐2‐pyrrolidone at elevated temperature. The polymers with inherent viscosities exceeding 0.5 were obtained after polymerization for 1 h using 2,4‐bis(fluorophenyl)‐6‐phenyl‐s‐triazine as a monomer. The glass transition temperatures of the resulting polymers ranged from 200 to 260°C depending on the bisphenol used in the polymer synthesis. The poly(arylene ether phenyl‐s‐triazine)s demonstrated excellent thermal stabilities in excess of 490°C (5% weight loss in air). The isothermal TGA measurements (400°C under air or nitrogen atmosphere) revealed that the 4,4'‐biphenol‐ and hydroquinone‐based poly(arylene ether phenyl‐s‐triazine)s belong to the most superior class of heat resistant polymers, such as polyimide Kapton™. The mechanical properties of these polymers are also described. © 1994 John Wiley & Sons, Inc.
Synthesis of thermotropic liquid crystal polyimide and its properties
Authors: Asanuma Tadashi , Oikawa Hideaki , Ookawa Yuuichi , Yamasita Wataru , Matsuo Mitunori , Yamaguchi Akihiro 
Published: April 2003

AbstractThermotropic liquid crystal polyimide which has neither an ester linkage nor a carbonate linkage was prepared by the polymerization of 1,2,4,5‐benzenetetracarboxylic dianhydride (PMDA) and 1,3‐bis[4‐(4′‐aminophenoxy)cumyl)]benzene (BACB). This polyimide shows the liquid crystal phase at 549‐593 K. Mixing this liquid crystal polyimide or copolymerizing BACB decreases the melt viscosity of the thermoplastic polyimide (Aurum). © 1994 John Wiley & Sons, Inc.
Preparation of poly(phosphate ester)s having bisphenol moieties as mesogenic units in the main chain
Authors: Sugiyama Kazuo , Makino Koji , Morita Masao , Yoshimitsu Yoshikuni 
Published: April 2003

AbstractPoly(phosphate ester)s, PPE 1a–d, were synthesized from polycondensation of methyl phosphorodichloridate (MPDC) with various bisphenols such as 4,4′‐biphenol 1a, 4,4′‐dihydroxyphenylether 1b, bis(4‐hydroxyphenyl)methane 1c, and 3,3′‐dimethyl‐4,4′‐dihy‐droxybiphenyl 1d. PPE 2a–d with hexamethylene spacers were also obtained from poly‐condensation of MPDC with 4,4′‐bis(6‐hydroxyhexyloxy)biphenyl 2a, 4,4′‐di(6‐hydroxyhexyloxy)phenyl ether 2b, bis[4‐(6‐hydroxyhexyloxy)phenyl]methane 2c, and 3,3′‐dimethyl 4,4′‐di(6‐hydroxyhexyloxy)biphenyl 2d. The degree of crystallinity of PPE 1a–1d without hexamethylene spacer was 3.3–17.6%, whereas PPE 2a and PPE 2b which exhibit mesomorphic behavior were 20.1 and 18.6%, respectively. PPE 2a and PPE 2b show the mesophase at 139.6–195.5°C and 42.4–66.3°C, respectively. PPE 2c and PPE 2d were obtained as rubbery. From pyrolysis of PPE in air the temperature corresponding to 5% weight loss was found to be 322–408°C and 284–291°C for PPE 1 and PPE 2, respectively. It was also found that PPE 2a was enzymatically degraded by phospholipase C. © 1994 John Wiley & Sons, Inc.
Photo‐initiated base‐formation in a polymer matrix
Authors: Ito Ken‐Ichi , Nishimura Masamichi , Sashio Minoru , Tsunooka Masahiro 
Published: April 2003

AbstractIt was found that amines were formed efficiently by the photolysis of O‐acyloximes followed by hydrolysis in polystyrene films and the relationship between structures of O‐acyloximes and yields of amines were investigated. O‐phenylacetyl acetophenone oxime (PaApO), O‐pivaloyl acetophenone oxime (PApO), and O‐benzoyl acetophenone oxime (BApO) as monofunctional O‐acyloximes and O,O′‐succinyl diacetophenone oxime (SDApO) and O,O′‐glutaryl diacetophenone oxime (GDApO) as bifunctional O‐acyloximes were examined. The yields of amines for PaApO and SDApO under N2 were ca. 70%, which was the highest among O‐acyloximes examined in this experiment. On the other hand, the yields for PApO, BApO, and GDApO were less than 15% and it was verified that the hydrogen abstraction by imino radicals via 6‐membered cyclic intermediates resulted in the lowering of yields. Although the effect of oxygen under photolysis on the yields of amine for PaApO was negligible under 50% conversion of PaApO, the yield decreased with further increase in the conversion and was 50% at 90% conversion. © 1994 John Wiley & Sons, Inc.
New fluorinated oxazoline block copolymer lowers the adhesion of platelets on polyurethane surfaces
Authors: Kaku Mureo , Grimminger Lisa C. , Sogah Dotsevi Y. , Haynie Sharon I. 
Published: April 2003

AbstractWe have prepared an amphiphilic oxazoline block copolymer of hydrophilic poly(2‐methyl‐2‐oxazoline) and hydrophobic poly[2‐(2‐perfluorooctyl)ethyl‐2‐oxazoline] chains. By controlling the length and composition of polymer chains, we found that this fluorinated block copolymer can be readily dissolved in water. Furthermore, we can achieve a stable surface coating of the fluorinated block copolymer by dissolving the copolymer in water, then coating the aqueous copolymer solution onto surfaces of nonwater‐soluble polymers. This is a simple and useful method of modifying the surface character of polymer substrates. We have found that the polyether urethane (PEU) coated by block copolymer has a different surface chemistry and biological reactivity than the uncoated PEU. From XPS analysis, we found the fluorinated copolymer was coated on PEU (atomic % of F: 31.3 on coated PEU, 0.3 on uncoated). The two surfaces have different affinities for biological molecules. Specifically, the fibrinogen adsorption on the fluorinated copolymer‐coated PEU was 62 ± 39 ng/cm2, compared to a value of 156 ± 99 ng/cm2 for uncoated PEU. In an ex vivo evaluation of platelet adhesion, the surface of coated PEU attached a few white cells while uncoated PEU was covered with activated platelets. © 1994 John Wiley & Sons, Inc.