bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amine/anhydride reaction versus amide/anhydride reaction in polyamide/anhydride carriers
Authors: Maréchal Philippe , Coppens Gaétane , Legras Roger , Dekoninck Jean‐Marc 
Published: April 2003

AbstractPolyamide 6 (PA6) and poly(metaxylene adipamide) (PAmXD6) were blended in a batch mixer with anhydrides such as phthalic anhydride, n‐octadecyl succinic anhydride, and anhydride‐grafted ethylene propylene rubber. The melt viscosity, the solution viscosity, and chain end concentration were studied during the mixing. PA was first mixed 5 min to get an homogeneous melt prior to the anhydride addition. The introduction of the anhydride to the molten polyamide resulted in large decreases of melt and solution viscosities and of amine chain end concentrations. The anhydride units react with amine chain ends to form imide groups. The resulting low amine chain end concentration causes hydrolysis reaction to maintain the condensation equilibrium. As a consequence an increased carboxylic chain end concentration is observed. The imide concentration was studied by IR. It was shown that when most of the amine chain ends are consumed, the remaining anhydride reacts with amino groups formed by polyamide hydrolysis. © 1995 John Wiley & Sons, Inc.
Synthesis of a tetra(maleimide) as intermediate compound in a linear Diels–Alder polyaddition of bismaleimides with bis(2‐pyrone)s
Authors: Alhakimi Gamil , Klemm Elisabeth 
Published: April 2003

AbstractThe tetrafunctional products 3 and 6 were synthesized via Diels‐Alder reaction of bis(2‐pyrone) with bismaleimides in mol ratio 1:7. The chemical structure of these products was determined by 1H‐NMR spectroscopy; the high degree of purity was confirmed by means of elemental analysis. The cyclization of the tetraimide 3 with 2 mol monopyrone 7 to the bicycle 8 was carried out. © 1995 John Wiley & Sons, Inc.
Synthesis of branched copolysilanes from trichlorosilanes
Authors: Sasaki Manabu , Matyjaszewski Krzysztof 
Published: April 2003

AbstractSoluble polymers and copolymers have been prepared from monosubstituted trichlorosilanes via thermal reductive coupling with sodium in toluene. Phenyltrichlorosilane has been copolymerized with methylphenyl dichlorosilane, with n‐hexyltrichlorosilane, with tetrachlorosilane and with tetrakis(chlorodimethylsilyl)silane. n‐Hexyltrichlorosilane has been copolymerized with methylphenyldichlorosilane, with phenyltrichlorosilane and with silicon tetrachloride. Soluble polymers and copolymers with molecular weight in the range ≈ 2,000 to ≈ 106 have been obtained. The absorption and emission spectra of the resulting polymers are strongly affected by the presence of trisilyl‐ and tetrasilylsubstituted silicon atoms. © 1995 John Wiley & Sons, Inc.
Synthesis and characterization of aromatic amine functional semicrystalline aryl ether ketone macromers
Authors: Bourgeois Y. , Devaux J. , Legras R. , Charlier Y. , Hedrick J. L. 
Published: April 2003

AbstractFrom earlier experiments it was observed that the reactions of aryl fluoride functional aryl ether ketone oligomers (PEK) with m‐aminophenol lead to poor levels of amine incorporation because of side‐reactions. In this article, a method is presented to protect the m‐aminophenol by converting it into a triarylimine group. This protected m‐aminophenol was used together with 4‐fluoro,4′‐hydroxybenzophenone in a typical poly(aryl ether) synthesis. PEKs of different molecular weights were synthesized with number average molecular weights \documentclass{article}\pagestyle{empty}\begin{document}$\overline {M}_n$\end{document}) of 2600, 4500, and 5400 g/mol. The deprotection of the triarylimine chain end was carried out by an acid treatment to afford a monofunctional aromatic amine end group, amenable towards copolymerization. © 1995 John Wiley & Sons, Inc.
Characterization of PET surface modification with CF4‐CH4 (CF4/CH4 > 5) RF plasma by XPS and contact angle techniques
Authors: Wei Xiang , Xiaodong Chen , Jianqi Wang 
Published: April 2003

AbstractRF plasma of CF4/CH4 (> 5) was subject to further investigation by XPS and the contact angle method. An attempt has been made aiming at distinguishing the mechanistic aspects of PET surfaces exposed to CF4/CH4 plasmas. It follows that in addition to region 3 (83.3–0.0% CF4) there are two regions within the range of 83.3–100% CF4. Region 1 (100–96.8% CF4) is a region of etching/fluorination predominated and region 2 (96.8–83.3% CF4) is polymerization predominated. For a complete description of the entire process the fluorination (or grafting, implantation) should be incorporated into the CAP model. The homogeneity along depth of the surface layers can be intuitively observed with the help of the angle‐dependent XPS, which turns out to be of great importance in comparison with the sampling depth of the contact angle technique under various experimental conditions. © 1995 John Wiley & Sons, Inc.
Molecular characterization of maleic anhydride‐functionalized polypropylene
Authors: De Roover B. , Sclavons M. , Carlier V. , Devaux J. , Legras R. , Momtaz A. 
Published: April 2003

AbstractThis work deals with the molecular characterization of maleic anhydride melt‐functionalized polypropylene (PP‐g‐MA). The functionalization mechanism, the nature, the concentration, and the location of grafted anhydride species onto the polypropylene chain are discussed. The polypropylene functionalization was performed using a pre‐heated Brabender Plastograph (190°C, 4 min of mixing time). Several concentrations of maleic anhydride and organic peroxide were used for this study. In those experimental conditions, the organic peroxide undergoes an homolytic rupture and carries out a polypropylene tertiary hydrogen abstraction. The resulting macroradical undergoes a β‐scission leading to a radical chain end which reacts with maleic anhydride. When a termination reaction occurs at this first step a succinic type anhydride chain end is obtained. However, oligomerization of maleic anhydride is found to occur more frequently leading to poly (maleic anhydride) chain end. Concentration of both anhydride types and minimal length of the grafted poly (maleic anhydride) were determined. A fraction of maleic anhydride does not react with polypropylene or homopolymerize leading to nongrafted poly (maleic anhydride). © 1995 John Wiley & Sons, Inc.
Reactivity of polymeric amines toward peptide bond formation‐aminolysis of poly(aminoacrylamide)s by N‐benzoylglycine 4‐nitrophenyl ester
Authors: Chandy Mathew C. , Pillai V. N. Rajasekharan 
Published: April 2003

AbstractPolymeric amines derived from copolymers of acrylamide (AA) cross‐linked with bifunctional crosslinking agents of varying polarity and hydrophilicity were studied for their reactivity in the aminolysis of N‐benzoylglycine 4‐nitrophenyl ester. The reaction did not follow simple kinetics. © 1995 John Wiley & Sons, Inc.
Investigations on monotropic liquid crystalline polyurethanes based on biphenylol
Authors: Haridas K. R. , Radhakrishnan Ganga 
Published: April 2003

Abstract2,2′‐Azobis‐[2‐cyano‐(4‐ethylphenol)] (ABCP) was prepared from parahydroxyacetophenone, using hydrazine sulfate and sodium cyanide. Biphenylol ester of ABCP, 2,2′‐azobis‐[2‐p‐biphenyloxy‐(4‐ethylphenol)] (BECP) was synthesized via the acid route. Combined liquid crystalline polyurethanes (CLCPUs) were synthesized from 1,6‐diisocyanatohexane (HDI) and BECP in dimethylformamide (DMF) at 110°C under nitrogen atmosphere. The effect of partial replacement of BECP by 4,4′‐dihydroxy biphenyl (DHBP) on liquid crystalline (LC) properties was studied. The polymers were characterized by proton and 13C NMR, FTIR, and UV spectroscopy. Elemental analysis were done for determining the percentage content of C, H, and N and the molecular weights of the polymers were determined by gel permeation chromatography (GPC). Thermogravimetric investigations (TGA) of the polyurethanes (PUs) were performed to study the decomposition. The LC nature of the PUs was confirmed by differential scanning calorimetry (DSC) and X‐ray diffraction (XRD). Cross‐polarized optical microscopy studies demonstrated the existence of two distinct crystalline morphologies, a spherulitic morphology with high mole ratio of DHBP and a thread‐like crystalline morphology with that of BECP. All the PUs synthesized showed a LC nature with a wide temperature range. Partial replacement of BECP by DHBP changed the mesomorphic nature, transition temperature, and temperature range of the mesophase. © 1995 John Wiley & Sons, Inc.
“Close loop” mechanistic schemes for hydrocarbon polymer oxidation
Authors: Audouin L. , Gueguen V. , Tcharkhtchi A. , Verdu J. 
Published: April 2003

AbstractMechanistic schemes of radical oxidation of hydrocarbon polymers in which initiation is only due to unimolecular or bimolecular hydroperoxide decomposition have been studied. The results of their kinetic analysis have been compared with literature data relative to the thermal oxidation of polypropylene in solid state (60‐160°C). These data are in remarkably good agreement with the “unimolecular” scheme whose main characteristics are: (1) the quasi‐independence of the kinetic behavior with initial conditions (for low initial content of thermolabile structures), and (2) the fact that an arbitrarily defined induction period depends only on the rate constant of unimolecular hydroperoxide decomposition. © 1995 John Wiley & Sons, Inc.
Photoinitiators with functional groups. III. Water‐soluble photoinitiators containing carbohydrate residues
Authors: Knaus S. , Gruber H. F. 
Published: April 2003

AbstractA series of new water‐soluble photoinitiators (PIs) for UV curing of water‐borne systems was synthesized by covalent bonding of carbohydrate residues such as D‐glucose, sucrose, maltose, 1‐amino‐D‐sorbitol and D‐gluconicacid‐δ‐lactone to the commercially available PI 2‐hydroxy‐1‐[4‐(2‐hydroxy‐ethoxy)phenyl]‐2‐methylpropan‐1‐one (Darocur 2959) (1). In addition, new functional derivatives of 1 containing tosyl‐ or chloride residues as well as primary or secondary amino groups were prepared. Preliminary photocalorimetric tests of the activity demonstrated excellent efficiencies of the PIs in a commercial water‐based acrylate formulation exceeding the photoactivity of the reference PI (1) substantially. © 1995 John Wiley & Sons, Inc.
Synthesis and reaction of polymers bearing 5‐membered cyclic dithiocarbonate group
Authors: Kihara Nobuhiro , Tochigi Hidefumi , Endo Takeshi 
Published: April 2003

Abstract5‐(Methacryloyloxy)methyl‐1,3‐oxathiolane‐2‐thione (3) was synthesized from glycidyl methacrylate (GMA) and carbon disulfide in the presence of lithium bromide in 93% yield. The radical polymerization of 3 in DMSO initiated by AIBN at 60°C afforded corresponding polymethacrylate 4 quantitatively. Copolymerization of 3 with MMA was also carried out. 5‐Phenoxymethyl‐1,3‐oxathiolane‐2‐thione (6), model dithiocarbonate, reacts with benzylamine at room temperature to afford O‐(1‐mercapto‐3‐phenoxy‐2‐propyl)N‐benzyl‐thiocarbamate (7) and 1,1′‐dithiobis[3‐phenoxy‐2‐(benzylaminothiocarbonyloxy)‐propane] (8) in 89% and 7% yield, respectively. Polymer 4 reacted with butylamine or dipropylamine to afford a corresponding polymethacrylate bearing thiol group, which immediately turned to insoluble gel by facile auto‐oxidation of the thiol group. © 1995 John Wiley & Sons, Inc.
A possible route to the controlled synthesis of polymethyloxirane oligomers using bimetallic μ‐oxoalkoxides
Authors: Taquet A. , Jérôme R. , Teyssié Ph. , Masy J. P. , Goethals E. 
Published: April 2003

AbstractSoluble μ‐oxo‐bimetallic trinuclear alkoxides are known to be very effective catalysts for the ring‐opening polymerization of oxiranes. In the particular case of methyloxirane, oligomers are formed in addition to high molecular weight polyethers. An alkoxide‐alcohol exchange reaction has proved to be an efficient way to form oligomers preferentially, when the monomer‐alcohol molar ratio is small. Upon increasing this ratio, formation of high MW chains occurs increasingly. The use of Ti instead of Al in Al, Zn μ‐oxo‐n‐butoxide in the presence for phenoxyethanol as a co‐initiator inhibits formation of exceedingly long polyether chains and the chain length is basically controlled by the monomer to all potential initiating species molar ratio until MW of ca. 6000. Substitution of phenoxyethanol by polypropylene glycol has led to oligomers of a monomodal MW distribution and a MW of 13,000. This study has highlighted that conditions unfavorable to coordination of the polyether chains onto the catalyst improve the control of the oligomer formation. © 1995 John Wiley & Sons, Inc.
Fluorinated NLO polymers with improved optical transparency in the near infrared
Authors: McCulloch Iain , Yoon Hyun 
Published: April 2003

AbstractThe absorption from vibrational overtones in the near infrared and specifically at 1.55 μm, is a major contribution to the optical loss of NLO polymer waveguides. In an effort to reduce this value, the specific molecular vibrations responsible, which had previously been predicted by theoretical means, were identified by solvent spectra analysis. A scheme was proposed to reduce the intrinsic absorption through synthetic modification of the polymer by replacement of appropriate aliphatic CH bonds with CF bonds. Specific bonds were chosen for replacement based on a consideration of both contribution to intrinsic absorption as well as ease of synthetic modification. The target polymer was synthesized and its absorption measured by a solution technique. A reduction in optical loss at 1.55 µ from 0.75 to 0.35 dB cm−1 was achieved. © 1995 John Wiley & Sons, Inc.
Solvent effects on ester alcoholysis at functionalized polyethylene surfaces
Authors: Bergbreiter David E. , Aguilar Gaston A. 
Published: April 2003

AbstractThe effects of solvent on the accessibility and reactivity of an ester‐bound fluorophore at a functionalized polyethylene‐solvent interface have been studied. Fluorophore‐labeled polyethylene surfaces were prepared by blending together a small amount of a pyrene esterterminated ethylene oligomer and a host linear low density polyethylene in solution. Films cast from such solutions were then studied by fluorescence spectroscopy to show that a significant number of the entrapped pyrene groups were at the polyethylene‐solvent interface and capable of reaction with soluble reagents. Subsequently, transesterification of these ester‐bound pyrenes using various sodium alkoxides in alcohol, alcohol‐toluene, or alcohol‐tetrahydrofuran solvent mixtures was studied by fluorescence and UV‐visible spectroscopic analysis of the supernatant. The extent of alcoholysis of such esters was found to be significantly affected by the solvent chosen and by the structure of the alcohol. © 1995 John Wiley & Sons, Inc.
Graft copolymers having hydrophobic backbone and hydrophilic branches. X. Preparation and properties of water‐dispersible polyanionic microspheres having poly(methacrylic acid) branches on their surfaces
Authors: Riza Medyan , Tokura Seiichi , Iwasaki Minoru , Yashima Eiji , Kishida Akio , Akashi Mitsuru 
Published: April 2003

AbstractThe free radical copolymerization of poly(t‐butyl methacrylate) (PBMA) macromonomer with styrene in ethanol give monodispersed microspheres with 0.8‐1.6 μm diameter. The resulting microspheres were treated with HCl solution to convert into anionic microspheres having poly(methacrylic acid) chains. ESCA analysis of the microsphere surface suggested that PBMA chains were favorably located on the surface of the microspheres. The particle size of the microspheres decreased with increasing molecular weight and concentration of the macromonomer. Water dispersibilities of the microspheres were evaluated by measuring the relative turbidity of the suspension of microspheres as a function of pH. The results show that they were strongly dependent on pH. © 1995 John Wiley & Sons, Inc.
Synthesis and polymerization of N‐[N′‐(α‐methylbenzyl)aminocarbonyl‐n‐alkyl]maleimide
Authors: Oishi Tsutomu , Kagawa Kensoh , Fujimoto Minoru 
Published: April 2003

AbstractTwo types of optically active N‐[N′‐(α‐methylbenzyl)amino/carbonyl‐n‐alkyl]maleimides (MBAC) were synthesized from maleic anhydride, 6‐amino‐n‐caproic acid (or 12‐amino‐n‐dodecanoic acid), and (R)‐(+)‐α‐methylbenzylamine. Radical homopolymerizations of MBAC were performed in several solvents at 60 and 110°C for 24 h to give optically active polymers. Radical copolymerizations of MBAC were performed with styrene (ST) and methyl methacrylate (MMA) in dioxane at 60°C. The monomer reactivity ratios and the Alfrey‐Price Q‐e values were determined. Chiroptical properties of the polymers and copolymers were investigated. © 1995 John Wiley & Sons, Inc.
Radical polymerization of vinyl monomer having diacylurea moiety
Authors: Kanamaru Masami , Takata Toshikazu , Endo Takeshi 
Published: April 2003

AbstractN‐acryloyl‐N′‐benzoylurea (1) was prepared and its radical homopolymerization and copolymerization with styrene were carried out. 1 was synthesized yield by the reaction of benzoylisocyanate and acrylamide in tetrahydrofuran in 78%. Radical polymerization of 1 was carried out at 60 or 80°C in DMF (0.1‐2.5M) for 5 h in a sealed tube using AIBN (3 mol %) or BPO (3 mol %) as initiators to obtain poly(N′‐acryloyl‐N′‐benzoylurea) (2) as a methanol‐insoluble part in good yield (75–82%) independent of concentration. Number‐average molecular weights of 2 were 2700–91,900. Furthermore, copolymerization of 1 with styrene was carried out in various feed ratios to confirm the alternating character in the copolymerization (r1r2 = 0.21) and Q, e values of 1 were evaluated as 0.52, 1.16, respectively. © 1995 John Wiley & Sons, Inc.
Gamma‐oxidation of linear low‐density polyethylene: The dose–rate effect of irradiation on chemical and physical modifications
Authors: Tidjani Adams , Watanabe Yasushi 
Published: April 2003

Abstractγ‐Oxidation of linear low‐density polyethylene based on hexene and butene was investigated. Irradiation was performed at different dose rates in air (from 2 rad/s to 100 rad/s). Degraded samples were analyzed with IR combined with NO and SF4 derivatizations. Our results showed that the lower the dose rate, the higher the degree of oxidation in terms of γ‐product formation. Ketone species appeared to be the dominant γ‐products. The G values of γ‐product formation were very dependent on the dose rate of initiation. Comparison of the G value ratio of different γ‐products revealed stoechiometry differences. The complex appearance and disappearance of unsaturations was tentatively explained. The modifications of elongation at break induced by γ‐irradiation were monitored by molecular changes in weight. This was not conclusive because changes in elongation at break are inconsistent with changes in Mw/Mn. © 1995 John Wiley & Sons, Inc.
Synthesis and polymerization of 1‐(2,4,6‐tricyanophenylthio)‐3‐[3,5‐bis(n,n‐dimethylamino)phenoxy]‐2‐propyl methacrylate; polymer effect on intramolecular charge–transfer interaction
Authors: Itoh Takahito , Noki Ryuichi , Simosato Shinji , Magara Isao , Iwatsuki Shouji 
Published: April 2003

Abstract1‐[3,5‐Bis(N,N‐dimethylamino)phenoxy]‐ω‐(2,4,6‐tricyanophenylthio)alkanes (1a–c), where an electron‐accepting 2,4,6‐tricyanophenylthio group and an electron‐donating 3,5‐bis(N,N‐dimethylamino)phenoxy one are linked with a spacer such as ethylene, trimethylene, and tetramethylene, were prepared in order to examine an effect of the spacer chain length on intramolecular charge–transfer interaction between the 2,4,6‐tricyanophenylthio and 3,5‐bis(N,N‐dimethylamino)phenoxy groups. From the UV‐vis spectra measurements of 1a–c, 1‐[3,5‐bis(N,N‐dimethylamino)phenoxy]‐3‐(2,4,6‐tricyanophenylthio)Propane (1b) carrying the trimethylene chain as a spacer was found to have the strongest intramolecular charge–transfer interaction. A new methacrylate‐type monomer carrying the 1b unit as a side chain, 1‐(2,4,6‐tricyanophenylthio)‐3‐[3,5‐bis(N,N‐dimethylamino)phenoxy]‐2‐propyl methacrylate (2), was prepared successfully in 9.2% total yield in seven steps. The monomer 2 homopolymerized in benzene, tetrahydrofuran, acetone, and dimethyl sulfoxide in the presence of 2,2′‐azobis(isobutyronitrile) at 60°C to give polymers [poly(2)] with molecular weights of 6,000 to 98,000. An intramolecular charge–transfer interaction in the poly(2) was found to be larger than that in the monomer 2 and to increase with an increase in the degree of polymerization of the poly(2), suggesting that there is an existence of polymer effect other than the polymer effect due to the high local concentration of the donor‐acceptor pair. © 1995 John Wiley & Sons, Inc.
Synthesis and properties of polyimides derived from 1,6‐bis(4‐aminophenoxy)naphthalene and aromatic tetracarboxylic dianhydrides
Authors: Yang Chin‐Ping , Hsiao Sheng‐Huei , Jang Chin‐Cheng 
Published: April 2003

Abstract1,6‐Bis(4‐aminophenoxy)naphthalene (I) was used as a monomer with various aromatic tetracarboxylic dianhydrides to synthesize polyimides via a conventional two‐stage procedure that included ring‐opening polyaddition in a polar solvent such as N,N‐dimethylacetamide (DMAc) to give poly(amic acid)s, followed by thermal cyclodehydration to polyimides. The diamine (I) was prepared through the nucleophilic displacement of 1,6‐dihydroxynaphthal‐ene with p‐chloronitrobenzene in the presence of K2CO3, followed by catalytic reduction. Depending on the dianhydrides used, the poly(amic acid)s obtained had inherent viscosities of 0.73–2.31 dL/g. All the poly(amic acid)s could be solution cast and thermally converted into transparent, flexible, and tough polyimide films. The polyimide films had a tensile modulus range of 1.53–1.84 GPa, a tensile strength range of 95–126 MPa, and an elongation range at break of 9–16%. The polyimide derived from 4,4′‐sulfonyldiphthalic anhydride (SDPA) had a better solubility than the other polyimides. These polyimides had glass transition temperatures between 248–286°C (DSC). Thermogravimetric analyses established that these polymers were fairly stable up to 500°C, and the 10% weight loss temperatures were recorded in the range of 549–595°C in nitrogen and 539–590°C in air atmosphere. © 1995 John Wiley & Sons, Inc.
Macromolecular synthesis from saccharic lactones. Polyaddition of D‐glucaro‐ and D‐mannaro‐ 1,4:6, 3‐dilactones with diisocyanates and hydrolyzability of the resulting polyurethanes having dilactone rings in the main chains
Authors: Hashimoto Kazuhiko , Wibullcksanakul Sirinat , Okada Masahiko 
Published: April 2003

AbstractPolyaddition of saccharic acid dilactones prepared from D‐glucose and D‐mannitol, D‐glu‐caro‐, and D‐mannaro‐1,4:6,3‐dilactones (1 and 2, respectively), with hexamethylene di‐isocyanate (3a) and methyl (S)‐2,6‐diisocyanatocaproate (3b) was carried out by using dibutyltin dilaurate as a catalyst at 50, 25, and 0°C to give polyurethanes (4 and 5) having dilactone moieties in the main chains. The resulting polymers were found to decompose easily in phosphate buffers under neutral or slightly basic conditions (pH 7 or 8). Therefore, the polyurethanes may be used as novel degradable polymeric materials. © 1995 John Wiley & Sons, Inc.