bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copolymerization of α‐terpineol with styrene: Synthesis and characterization
Authors: Yadav Sarika , Srivastava A. K. 
Published: April 2003

AbstractRadical copolymerization of α‐terpineol with styrene (Sty) initiated by azobisisobutyronitrile in xylene at 80 ± 0.1 °C for 2 h followed ideal kinetics and resulted in the formation of a functional and alternating copolymer as evidenced by spectral analysis. The activation energy was 28 kJ/mol. α‐Terpineol underwent copolymerization as well as a chain‐transfer reaction. The values of the monomer reactivity ratios calculated by the Kelen–Tüdos method were r1 (Sty) = 0.033 and r2 (α‐terpineol) = 0.004. The Alfrey–Price Q‐e parameters for α‐terpineol were calculated as 0.104 and 3.052, respectively. The mechanism of copolymerization is elucidated, and it is concluded that the double bond present in the monocyclic ring of α‐terpineol is an active site for copolymerization. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1700–1707, 2003
Photocurable and thermally stable polymers based on 1,4‐pentadien‐3‐one‐1‐p‐hydroxyphenyl‐5‐p‐phenyl methacrylate: Copolymerization with ethyl acrylate
Authors: Arun A. , Reddy B. S. R. 
Published: April 2003

Abstract1,4‐Pentadien‐3‐one‐1,5‐bis(p‐hydroxyphenyl) (PBHP) was prepared by reacting p‐hydroxybenzaldehyde and acetone in the presence of an acid catalyst. 1,4‐Pentadiene‐3‐one‐1‐p‐hydroxyphenyl‐5‐p‐phenyl methacrylate (PHPPMA) monomer was prepared by reacting PBHP dissolved in ethyl methyl ketone (EMK) with methacryloyl chloride in the presence of triethylamine. A free‐radical solution polymerization technique was used for synthesizing homo‐ and copolymers of different feed compositions of PHPPMA and ethyl acrylate (EA) in EMK as a solvent with benzoyl peroxide as a free‐radical initiator at 70 ± 1 °C. All the polymers were characterized with IR and 1H NMR techniques. The compositions of the copolymers were determined with the 1H NMR technique. The copolymer reactivity ratios were evolved with Kelen–Tudos (EA = 1.25 and PHPPMA = 0.09) and extended Kelen–Tudos (EA = 1.30 and PHPPMA = 0.09) methods. Q (0.48) and e (1.68) values for the new monomer (PHPPMA) were calculated with the Alfrey–Price method. UV absorption spectra for poly(PHPPMA) showed two absorption bands at 302 and 315 nm. The photocrosslinking properties of the polymer samples were examined with the solvent method. Thermal analyses of the polymers were performed with the thermogravimetric‐differential thermogravimetric technique. First, the decomposition temperatures started for poly(PHPPMA), copoly(EA‐PHPPMA) (62:38), and copoly(EA‐PHPPMA) (41:59) were at 350, 410, and 417 °C, respectively. A gel permeation chromatographic method was used for determining the polymer molecular weights (weight‐average molecular weight: 2.67 × 104 and number‐average molecular weight: 1.41 × 104) and polydispersity index (1.89). The solubility of the monomer and the copolymers occurred at 30 °C with solvents having different polarities. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1632–1640, 2003
Homopolymerization of methyl methacrylate by novel salicylaldiminate‐nickel/methylaluminoxane catalysts obtained by oxidative addition of the chelate ligand to a nickel(0) precursor
Authors: Carlini Carlo , Martinelli Marco , Raspolli Galletti Anna Maria , Sbrana Glauco 
Published: April 2003

AbstractSalicylaldimine ligands, such as 5‐nitro‐N(2,6‐diisopropylphenyl)salicylaldimine, 3,5‐dinitro‐N(2,6‐diisopropylphenyl)salicylaldimine, and 3‐phenyl‐N(2,6‐diisopropylphenyl) salicylaldimine were checked in the oxidative addition to bis(1,5‐cyclooctadiene)nickel(0) to prepare, after activation by methylaluminoxane (MAO), novel nickel‐based catalytic systems active in the polymerization of methyl methacrylate. The catalytic behavior of the aforementioned systems, in terms of activity, molecular weight, and polydispersity of the resulting poly(methyl methacrylate) as well as its stereoregularity degree, was investigated as a function of the Al/Ni molar ratio, reaction temperature, and nature of the salicylaldimine ligand. The effect of ethylene atmosphere present during the preparation of the catalyst precursors was also investigated. The results are discussed and compared with those previously obtained by bis(salicylaldiminate)nickel(II)/MAO catalytic systems. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1716–1724, 2003
Synthesis of transition‐metal‐ion‐selective poly(N‐isopropylacrylamide) hydrogels by the incorporation of an Aza crown ether
Authors: Kuckling Dirk , Pareek Pradeep 
Published: April 2003

AbstractA functionalized cyclam was synthesized by the attachment of a polymerizable acryloyl group to one of the four nitrogens on the cyclam molecule. The polymerization of the functionalized cyclam was performed with N‐isopropylacrylamide and N,N′‐methylene bisacrylamide, and the gels obtained were studied in the presence of different transition‐metal‐ion solutions. There was a drastic difference in the phase‐transition temperature (Tc) of the poly(N‐isopropylacrylamide) (PNIPAAm)/cyclam gel in comparison with the pure PNIPAAm gel. For the described system, a Tc shift of 15 °C was obtained. The presence of functionalized cyclam increased the hydrophilicity and Tc of the aforementioned polymer gels in deionized water (at pH 6) because of the presence of protonated amino moieties. The PNIPAAm/cyclam gels showed a dependence of the swelling behavior on pH. Tc of the pure PNIPAAm gel was weakly influenced by the presence of any transition‐metal ions, such as Cu2+, Ni2+, Zn2+, and Mn2+. The addition of Cu2+ or Ni2+ to the PNIPAAm/cyclam gel reduced Tc of the polymer gel, and a shift of approximately 12 °C was observed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1594–1602, 2003
Novel acrylic macromonomer with amphiphilic character derived from Triton X‐100: Radical copolymerization with methyl methacrylate and thermal properties
Authors: Larraz Elena , Elvira Carlos , San Román Julio 
Published: April 2003

AbstractThis article explores the synthesis of a novel methacrylic macromonomer with an amphiphilic character derived from poly(ethylene glycol) tert‐octylphenyl ether (MT) and its respective homopolymer. To know their reactivity in radical copolymerization reactions with methyl methacrylate (MMA), a model monomer (MTm) was synthesized to determine the reactivity ratios and compare them with the low molar fractions of copolymers of MT with MMA because they were difficult to isolate. They were rMTm = 0.97 and rMMA = 0.95. The compositional diagrams when representing the weight fraction of MT and MTm in the feed and the copolymer suggested that a clear correlation exists between the experimental points of the model monomer MTm and the macromonomer MT ones, suggesting that the length of the side poly(ethylene oxide) chain does not affect the reactivity of the methacrylic double bond in the prepared monomers for this type of polymerization reaction. The reactivity ratios of the copolymers have a tendency for the formation of random or Bernoullian copolymers. The glass‐transition temperatures (Tg's) of the prepared copolymers were determined by differential scanning calorimetry, deviated from the Fox equation, and discussed on the basis of treatments that consider the influence of the monomeric units along the copolymer chains, determining the Tg of the corresponding alternating dyads. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1641–1649, 2003
Conformational analysis of dipeptide‐derived polyisocyanides
Authors: Cornelissen Jeroen J. L. M. , Graswinckel W. Sander , Rowan Alan E. , Sommerdijk Nico A. J. M. , Nolte Roeland J. M. 
Published: April 2003

AbstractThe conformational properties of polymers derived from isocyanodipeptides have been investigated with a combination of model calculations, X‐ray diffraction, and circular dichroism spectroscopy. Depending on the configuration of the side chains, defined arrays of hydrogen bonds along the polymeric backbone are formed. This leads to a well‐defined conformation as, for example, expressed in the formation of lyotropic liquid‐crystalline phases and increased helical stability. Upon the disruption of the hydrogen bonds by a strong acid, a less well‐defined macromolecular conformation is observed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1725–1736, 2003
Roles of rhenium diimine complexes as metal‐ion probes and photosensitizers in functional polyurethanes
Authors: Hui Ching Sum , Lam Lillian Sze Man , Yin Chun , Chan Wai Kin , Djurišić Aleksandra B. 
Published: April 2003

AbstractPolyurethanes incorporated with rhenium diimine complexes were synthesized. The polymers exhibited interesting morphologies and solution properties. Results from gel permeation chromatography suggested the formation of polymer aggregates in solutions. The polymers could act as probes for metal ions. The addition of metal ions to polymer solutions led to significant changes in the electronic absorption properties of the polymer solutions. This was attributed to the interactions between the polyether moieties and metal ions. The metal complexes could also act as efficient photosensitizers. After doping with charge‐transport viologens, the photoconductivity of the polymers was greatly enhanced. The experimental quantum efficiency was simulated with Onsager's theory. The thermalization distances and the primary yields were typically 12–14 Å and 10−3, respectively. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1708–1715, 2003
Synthesis and self‐assembly of a chiral alternating sexithiophene–undeca(ethyleneoxy) block copolymer
Authors: Henze Oliver , Fransen Michel , Jonkheijm Pascal , Meijer E. W. , Feast W. James , Schenning Albertus P. H. J. 
Published: April 2003

AbstractAn oligothiophene/chiral oligo(ethyleneoxy) block copolymer (PolyT6) has been synthesized in which a sexithiophene block alternates with a well‐defined chiral undeca(ethyleneoxy) block. The polymer shows good solubility in chloroform, and ultraviolet–visible studies in this solvent reveal a spectrum similar to that of the chirally substituted monomeric sexithiophene (T6) analogue. The aggregation of PolyT6 occurs in dioxane; however, no helicity is present in this aggregate, in contrast to aggregated T6. This behavior illustrates that although the processability and mechanical robustness of block copolymers may be superior to those of analogous oligomers, the degree of self‐assembled order found in oligomer‐based systems may be lost in the polymers. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1737–1743, 2003
Copolymerization of cationic monomers with acrylamide in an aqueous solution
Authors: Tanaka Hiroo 
Published: April 2003

AbstractThe radical copolymerizations of commercially available cationic monomers (M1) with acrylamide (M2) have been investigated at pH 6.1 in aqueous solutions. The cationic groups in copolymers were analyzed by a colloid titration method and the reactivity ratios were determined by the Fineman–Ross method. The values of r1 and r2 were 1.71 and 0.25 for methacryloyloxyethyltrimethylammonium chlorideM2, 1.68 and 1.26 for N,N‐dimethylaminoethylmethacrylateM2, 1.13 and 0.57 for methacrylamidopropyltrimethylammonium chlorideM2, 1.10 and 0.47 for N,N‐dimethylaminopropylmethacrylateM2, 0.47 and 0.95 for N,N‐dimethylaminopropylacrylamideM2, 0.48 and 0.64 for acryloyloxyethyltrimethylammonium chloride‐M2, and 0.58 and 6.7 for dimethyldiallylammonium chloride‐M2 systems. The Alfrey‐Price Q and e values were calculated and the linear relationship between log Q and ultraviolet absorption maxima of cationic monomers was found.
Carbazole substituted N‐acylated linear polyethylenimines (PEI). synthesis and characterization of poly[N‐(9‐carbazolyl)acetylethylenimine] and poly[N‐(2‐(9‐carbazolyl))propanoylethylenimine]
Authors: Arora Kartar S. , Overberger C. G. 
Published: April 2003

AbstractThe synthesis of carbazola substituted N‐acylated polyethylenimines, namely, poly[N‐(9‐carbazolyl)acetylethylenimine] 20 and poly[N‐(2‐(9‐carbazolyl))propanoylethylenimine] 21 by a grafting reaction onto PEI and isomerization polymerization of the carbazole substituted 2‐oxazolines is reported. A complete acylation of amino groups in PEI by the 9‐carbazolylacetyl groups was achieved by the p‐nitrophenyl active ester method but PEI was only partially N‐acylated by the 2‐(9‐carbazolyl)propanoyl groups under similar reaction conditions. The carbazole substituted 2‐oxazolines, namely, 2‐(9‐carbazolyl)methyl‐2‐oxazoline 18 and (R,S)‐2‐[1‐(9‐carbazolyl)]ethyl‐2‐oxazoline 19, were prepared by a base induced cyclization of ß‐chloroamides. The ring‐opening isomerization polymerization of 18 and 19 in the molten state with a cationic initiator (dimethyl sulfate, methyl triflate, or ethylene glycol ditosylate) gave 20 and 21. Gel permeation chromatography of 20 and 21 obtained with different monomerto‐initiator ratios gave evidence of a chain transfer reaction with the monomer. The polymers were characterized by elemental analyses, IR, and 1H‐NMR spectroscopy.
Permeation control of ionic fluorescent probes by ambient pH changes from nylon capsule membranes depending on their microstructures
Authors: Seki Takahiro , Okahata Yoshio 
Published: April 2003

AbstractPermeations of water‐soluble, ionic fluorescent probes from a large, ultrathin nylon‐2,12 capsule membrane were largely affected by the ambient pH of the outer medium; permeations of cationic and anionic probes were accelerated by a factor of 50–100 in the basic and acidic medium, respectively, relative to that in the neutral‐pH region. The permeation of NaCl and nonionic fluorescent probes was hardly affected by the ambient pH. The nylon capsule membrane was elucidated to have an asymmetrical structure: the dense‐thin inner layer and the porous‐thick outer part. The pH‐sensitive permeation could be explained due to the ionization of a small amount of residual end‐groups (COOH and NH2) existing in the dense‐thin inner layer of the nylon capsule membrane.
Cationic polymerization of p‐methylstyrene initiated by acetyl perchlorate: An approach to living polymerization
Authors: Tanizaki Akio , Sawamoto Mitsuo , Higashimura Toshinobu 
Published: April 2003

AbstractThe cationic polymerization of p‐methylstyrene initiated by acetyl perchlorate at −78°C led to long‐lived (living‐like) polymers with a narrow molecular weight distribution (M̄w/M̄n = 1.1–1.4) in methylene chloride containing a common ion salt (n‐Bu4NClO4) or in a less polar solvent (CH2Cl2/toluene, 1/4v/v). Under these conditions, the number‐average molecular weight (M̄n) of the polymers increased in proportion to monomer conversion and was regulated by the monomer‐to‐initiator ratio. When fresh feeds of the monomer were repeatedly added to a completely polymerized solution, the polymerization ensued at the same rate as before and the linear increase in M̄n with monomer conversion continued. The effects of solvent polarity and the common ion salt on the polymerization showed the suppression of the ionic dissociation of the propagating species, resulting in a “nondissociated species,” to be the key factor for the formation of the long‐lived polymers.
Preparation of silicon‐containing polymers IV. Thermally stable organosilicon poly‐1,2,4‐triazoles
Authors: Ghatge N. D. , Jadhav J. Y. , Shinde B. M. , Misra B. M. 
Published: April 2003

AbstractNovel silicon‐containing poly‐1,2,4‐triazoles have been synthesized by the reaction of polyhydrazide precursors and aniline in polyphosphoric acid (PPA) at 260°C. The polyhydrazide intermediates were prepared from aromatic dihydrazides and silicon‐containing acid dichlorides via interfacial polycondensation. These polymers and their intermediates were characterized by infrared spectroscopy (IR), solubility, and by solution viscosity. The thermal behavior of these polytriazoles has been studied by dynamic thermogravimetry.
Determination of molecular weight distribution of nylon 12 by gel permeation chromatography
Authors: Ogawa Toshio , Sakai Masakazu , Ishitobi Wataru 
Published: April 2003

AbstractMolecular weight distribution of Nylon 12 was determined with hexafluoroisopropanol/toluene mixture as eluent by gel permeation chromatography. Calibration curve for Nylon 12 was easily obtained from that of polystyrene because the method of universal calibration was applicable among these polymers. The molecular weight distributions of Nylon 12 were always broader than expected by the theory of polymerization, i.e., most probable distribution. This result was not caused by broadening effect in gel permeation chromatography, but by polymerization itself.
Polymers of ortho‐vinylbenzaldehyde
Authors: Roth Robert J. G. , Rudin Alfred , Tchir Morris F. 
Published: April 2003

AbstractOrtho‐vinylbenzaldehyde has been prepared in a three‐step synthesis. Vacuum‐degassed monomer was polymerized with azodiisobutyronitrile initiator in bulk and in solution in 2‐butanone. The kp/kt1/2 value at 60°C is 4.7 × 10−2 L1/2 mol−1/2s−1/2. This is about twice the ratio for styrene. Chain transfer to monomer appears to be significant. Insoluble, crosslinked products were produced at high conversions, because of chain transfer to polymer. Tg of poly(ortho‐vinylbenzaldehyde) was found to be 142°C.Polymers made under N2 atmosphere often contained acetal groups. These can be produced by acid catalysis in the presence of small concentrations of ortho‐vinylbenzyl alcohol. A laddertype structure is produced.The monomer is capable of photoinitiation. Insoluble gels were produced in bulk monomer at all conversions. The initiation rate was very high and crosslinking resulted from combination of radicals produced from photolysis of the pendant 0‐benzaldehyde groups in the macromolecules.
Cationic polymerization initiated by intercalation compounds of lewis acids. II. Initiating ability and mechanism of action of the initiators
Authors: Rashkov Iliya Bl. , Gitsov Ivan 
Published: April 2003

AbstractThe initiating ability of the graphite intercalation compounds (GICs) of SbCl5, FeCl3, and AlBr3 was investigated. It was found that GICs were able to initiate the polymerization of monomers of different types–cyclosiloxanes, 1,2‐epoxides, vinyl ethers, lactones, and vinyl monomers. GICs of SbCl5 initiated also the polymerization of tetrahydrofuran. The interaction of the monomers (with the exception of the lactones) caused a size increase of the GICs and deformations in their lamellar structure. Relatively high‐molecular poly(vinyl ethers) and polydimethylcyclosiloxanes were obtained. The mechanism of action of GICs was discussed.
Radical copolymerization of γ‐methylene‐Δα,β‐butenolide derivative: ethyl(E)‐5‐OXO‐2,5‐dihydrofuran‐2‐ylidene‐acetate
Authors: Nagai Katsutoshi , Akiyama Kazuhiko , Kuramoto Noriyuki 
Published: April 2003

AbstractRadical polymerications including co‐ and terpolymerizations of a γ‐methylene‐Δα,β‐butenolide derivative, ethyl (E)‐5‐oxo‐2,5‐dihydrofuran‐2‐ylideneacetate(EODY) was investigated. The monomer had no homopolymerizability but copolymerized with styrene (ST) and 1,3‐cyclohexadiene to yield alternating copolymers. From IR and 1H‐NMR spectra of the copolymers, the 1,4‐addition was confirmed to exclusively occur for the conjugated double bond of EODY. Terpolymerization for the system involving an acceptor monomer such as maleic anhydride, α‐chloromaleic anhydride, or 7,7,8,8‐tetracyanoquinodimethane in addition to ST and EODY gave the terpolymer containing about 50 mol% of ST, in spite of a high fraction of ST in the feed. It was inferred that such an apparent behavior of EODY as an acceptor monomer could be due to a resonance‐stabilization of the propagating radical having EODY as a terminal unit, which is also responsible for the poor yields of the copolymers and terpolymers.
Synthesis and characteristics of microspheres of polystyrene derivatives
Authors: Shahar Michal , Meshulam Haim , Margel Shlomo 
Published: April 2003

AbstractTwo sytrene derivatives formylstyrene and styrene sulfonylcholoride, were synthesized. Polymeric microspheres in diameters ranging from 0.1 to 2 μm were synthesized by polymerization of chlormoethylstyrene, formylstyrene, and styrene sulfonylcholoride in organic solvents, in the presence of appropriate surfactants. The kinetics of microsphere formation were studied. The molecular weight distribution of the products was determined by gel permeation chromatography. Conditions for binding various amino ligands to the microspheres were also established.
Photolabeling studies of polymer–cell surface interaction. Evaluation of 3‐[(4‐azidophenyl)dithio]propionic acid as a polymer‐bound photolabel
Authors: Ramaswami V. , Tirrell D. A. 
Published: April 2003

Abstract3‐[(4‐Azidophenyl)dithio]propionic acid (1a) was prepared in four steps from 4,4′‐diamino‐diphenyldisulfide. Attachment of 1a to poly[(3‐hydroxypropyl)oxirane] was accomplished under very mild conditions via an acid‐catalyzed caarbodiimide coupling. Photolysis of polymer‐bound 1a with an electronic flash unit proceeded without detectable disulfide bond cleavage. Mild reduction of the disulfide bond of an analogue of 1a which carried no azido group confirmed that 1a should be useful in photolabeling studies of polymer–cell surface interaction.
Radiation resistant amorphous–all aromatic polyarylene ether sulfones: Synthesis, characterization, and mechanical properties
Authors: Hedrick J. L. , Mohanty D. K. , Johnson B. C. , Viswanathan R. , Hinkley J. A. , McGrath J. E. 
Published: April 2003

AbstractThe synthesis and characterization of amorphous, aromatic, polyaryl ethers has been investigated. Detailed synthesis procedures are provided. The main thrust of these activities was to synthesize polymers which could serve as castable amorphous matrix resins for carbonfiber composites and which would be highly resistant to radiation degradation. It was important that these polymers not contain any aliphatic groups in order to contrast their behavior with the commercially available Bisphenol‐A polysulfones. The approach taken was to synthesize a series of statistical or random copolymers derived from hydroquinone and biphenol together with 4,4′‐dichlorodiphenyl sulfone. In order to produce copolymers of high molecular weight, modified techniques were developed which utilized potassium carbonate as a weak base and N‐methyl‐2‐pyrrolidone as the aprotic dipolar solvent. Detailed procedures are provided in this paper for the synthesis of high molecular weight copolymers of this type. In addition, stress‐strain, dynamic mechanical properties and preliminary electron beam (e‐beam) degradation studies are reported significantly. Improved mechanical property retention after e‐beam exposure was observed with the all aromatic polyether sulfones.
Correlation of thermal degradation mechanisms: Polyacetylene and vinyl and vinylidene polymers
Authors: Montaudo Giorgio , Puglisi Concetto , Scamporrino Emilio , Vitalini Daniele 
Published: April 2003

AbstractThe thermal degradation of poly(vinyl bromide) (PVB), poly(vinyl chloride) (PVC), poly(vinyl alcohol) (PVA), poly(vinyl acetate) (PVAc), poly(vinyl fluoride) (PVF), poly(vinylidene chloride) (PVC2), and poly(vinylidene fluoride) (PVF2) has been studied by direct pyrolysis–mass spectrometry (DP‐MS) and flash pyrolysis–gas chromatography–mass spectrometry techniques. Vinyl and vinylidene polymers exhibit two competitive thermal degradation processes: (1) HX elimination with formation of polyene sequences which undergo further moleculaar rearrangements, and (2) main‐chain cleavage with formation of halogenated or oxigenated compounds. The overall thermal degradation process depends on the prevailing decomposition reaction in each polymer; therefore, different behaviors are observed. The thermal degradation of polyacetylene (PA) has also been studied and found important for the elucidation of the thermal decomposition mechanism of the title polymers.