bluuebunny/crossref_metadata_2025 huggingface dataset:
Survey of a catalyst system for living cationic polymerization of glucose‐carrying vinyl ethers with acetyl and isopropylidene protecting groups
Authors: Yamada Kenji , Yamaoka Katsushi , Minoda Masahiko , Miyamoto Takeaki
Published: August 2002

This study concerns the living cationic polymerization of two vinyl ethers (VEs) having pendant glucose residues, in which the hydroxyl groups are protected by acetyl and isopropylidene functions. Living cationic polymerization of VE having an acetyl‐protected glucose was achieved by employing an initiating system consisting of the CF3COOH adduct of isobutyl VE (IBVE) and ethylaluminium dichloride in the presence of an added base at 0 °C. In contrast, the use of the HCl adduct of IBVE in conjunction with zinc iodide at −15 °C was more suitable for the controlled polymerization of VE having an isopropylidene‐protected glucose. Polymers obtained under these reaction conditions had narrow molecular weight distributions (Mw/Mn ∼ 1.1) and controlled molecular weights.

© 2001 Society of Chemical Industry
Part 2. Quantitative interpretation of model compound sulfonation
Authors: Daoust D , Devaux J , Godard P
Published: August 2002

The mechanism and kinetics of sulfonation of two PEEK model compounds in concentrated sulfuric acid were studied. The first model compound (monomer) is representative of a PEEK repeat unit. The second one is a PEEK dimer. Because both model compounds are fluoroarylketone‐ended, the sulfonation reactions were followed by 19F NMR.

The sulfonation reactions were treated following a first‐order kinetics with respect to the unsulfonated PEEK repeat unit. The comparison between the monomer and dimer results showed two different types of sulfonation behaviour. If only one apparent kinetic constant is considered for monomer sulfonation, two kinetic constants were taken into account to describe the dimer sulfonation process. This is due to a rate slowing effect of a sulfonic acid group on the sulfonation of the adjacent PEEK repeat unit. Furthermore, the results also confirm the rate slowing effect of the fluorine atom on the sulfonation of the neighbouring PEEK repeat unit.

© 2001 Society of Chemical Industry
Synthesis and characterization of poly(methylphenylsilylene)–poly(ethylene oxide) and poly(methylphenylsilylene)–polyisoprene multiblock copolymers
Authors: Hiorns Roger C , Holder Simon J , Schué François , Jones Richard G
Published: August 2002

Multiblock copolymers were synthesized through condensation reactions of end‐groups of α,ω‐dichloro‐poly(methylphenylsilylene) with hydroxyl end‐groups of poly(ethylene glycol) or the chain‐ends of ‘living’ polyisoprenyl disodium. Optimum conditions have been sought through kinetic studies and by investigation of model reactions. The overall molecular weight distribution of poly(methylphenylsilylene)‐block‐poly(ethylene oxide) is characterized in terms of Flory's theory of condensation reactions, while the limiting step in the reaction is tentatively attributed to the formation of aggregates.

© 2001 Society of Chemical Industry
Crystallization behaviour of hindered phenol on chlorinated polyethylene matrix
Authors: Wu Chifei , Yamagishi Tada‐aki , Nakamoto Yoshiaki
Published: August 2002

The crystallization behaviour of tetrakis[methylene‐3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propionyloxy]methane (AO‐60) molecules from several different states was investigated. It was found that, while pure AO‐60 is a crystalline substance, quenched and isothermally annealed AO‐60 is amorphous. In the case of a mixture of chlorinated polyethylene (CPE) and AO‐60, the crystallization of AO‐60 molecules is greatly affected by the initial dispersion state of the molecules. In addition, the mobility of AO‐60 molecules, which is governed by the annealing temperature and the distribution of the chain‐ends of CPE, also influences crystal growth. A CPE/AO‐60 hybrid annealed at a temperature near the melting point of AO‐60 exhibited several endothermal shoulders in addition to a sharper peak when characterized by differential scanning calorimetry. They were attributed to melting of the two kinds of crystal found either on the surface or inside the specimen. The former changes from polyhedron to platelet and then to needle shapes as the annealing temperature is reduced, whereas the latter exhibits some which are unprecedented such as deformed (warp, twist, turn and hollow) platelets.

© 2001 Society of Chemical Industry
Evaluation of the termination mode in the radical polymerization of 2,2,2‐trifluoroethyl α‐fluoroacrylate
Authors: Alric Jérôme , David Ghislain , Boutevin Bernard , Rousseau Alain , Robin Jean‐Jacques
Published: August 2002

The mode of termination of 2,2,2‐trifluoroethyl α‐fluoroacrylate (FATRIFE) in radical polymerization was studied, and only termination by recombination occurred, which led to telechelic macromolecular structures. The radical polymerization in acetonitrile was carried out to synthesize oligomers with a low number average degree of polymerization ($\overline{\hbox{DP}_{\rm n}}$)cum (about 20), using tert‐butylcyclohexyl peroxydicarbonate (TBCPC) as initiator at 75 °C. The initial [TBCPC]0/[FATRIFE]0 molar ratio was monitored to evaluate its influence on the ($\overline{\hbox{DP}_{\rm n}}$)cum of α‐fluoroacrylic oligomers. The 1H NMR analysis of the polymers showed that the ($\overline{\hbox{DP}_{\rm n}}$)cum values obtained were higher than 40, in spite of a high C0 value. To explain these results, the mode of termination was evaluated using the following kinetic law: ${\bf R}_{\bf pi}\ {\bf\approx}\ [{\bf I}_{2}]_{0}^{0.27}[{\bf M}]_{0}^{1.24}$. The development of kinetic relationships allowed us to calculate the ratio kprt/ki·kp as about 17–30 mol s l−1, and to confirm that primary radical termination (PRT) was in competition with bimolecular macromolecular termination (BMT).

© 2002 Society of Chemical Industry
Student violence and the moral dimensions of education
Authors: Edwards Clifford H.
Published: August 2002

Student violence has started to appear in schools in extreme forms. Various causes have been suggested, including TV violence, dysfunctional families, grinding poverty, child abuse, domestic violence, poor emotional and cognitive development, drugs, gangs, inequitable educational opportunity, and latchkey homes. A number of programs have been initiated to deal with this problem which focus on limiting the entry of weapons into the schools and managing aggressiveness. Unfortunately many of these programs fail to address the more fundamental causes of violence and aggression. A more effective means of prevention involves helping children become more responsible members of families, schools, and neighborhoods. School counselors and school psychologists have an important leadership role in helping reduce violence by promoting the moral dimensions of education, including the development of effective learning communities and encouraging school experiences which help children become more resilient in meeting the challenges they face each day without resorting to violence. © 2001 John Wiley & Sons, Inc.
Cleft‐like hexaamine ligands containing large heteroaromatic moieties as receptors for both anions and metal cations
Authors: Bazzicalupi Carla , Bencini Andrea , Berni Emanuela , Bianchi Antonio , Fornasari Patrizia , Giorgi Claudia , Masotti Andrea , Paoletti Piero , Valtancoli Barbara
Published: August 2002

Ligands L1 and L2 contain two ethylenediamine chains linked to the 2,9 and 6,6′ positions of phenanthroline and bipyridyl, respectively. Their molecular architecture defines a coordinative ‘cleft,’ a potential binding site for metals and anionic species. Their coordination properties toward Zn(II), Cd(II) and Pb(II) were studied by means of potentiometric, microcalorimetric and UV–vis spectrophotometric measurements. In the [ML]2+ complexes (L = L1 or L2), the metal is enveloped inside the ligand cleft, as shown by the crystal structure of the [ZnL2]2+ cation. On the other hand, the analysis of the thermodynamic data for metal complexation reveals that in the [ML]2+ complexes some nitrogen donors are weakly bound, or not bound, to the metal, owing to the presence of a rigid heteroaromatic unit, which leads to a stiffening of the ligands. Both L1 and L2, in their protonated forms, behave as multifunctional receptors for the nucleotide anions at neutral or slightly acidic pH, giving 1:1 complexes. Binding of diphosphate, triphosphate, ATP and ADP was studied by means of potentiometry and 1H and 31P NMR spectroscopy. Charge–charge and hydrogen bonding interactions take place between the polyphosphate chain of nucleotides and the polyammonium groups of L1 and L2, whereas the adenine moiety shows charge–dipole interactions with the ammonium groups and π‐stacking with the heteroaromatic units of the receptors. Copyright © 2001 John Wiley & Sons, Ltd.
Synthesis and characterization of new hyperbranched poly(aryl ether oxadiazole)s
Authors: Wu Fang‐Iy , Shu Ching‐Fong
Published: August 2002

A new AB2 monomer was synthesized for use in the preparation of a hyperbranched poly(aryl ether oxadiazole) with terminal phenol functionality. The AB2 monomer contains two phenolic groups and a single aryl fluoride group that is activated toward nucleophilic displacement by the attached oxadiazole ring. The nucleophilic substitution of the fluoride with the phenolate groups led to the formation of an ether linkage. Subsequently, a hyperbranched poly(aryl ether oxadiazole) having approximately a 44% degree of branching, as determined by a combination of model compound studies and 1H NMR, was obtained. The terminal phenolic groups underwent facile functionalization, furnishing hyperbranched polymers with a variety of functional chain ends. The nature of the chain‐end groups had a significant influence on the physical properties of the polymers, such as the glass‐transition temperature and their solubility. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3851–3860, 2001
Side‐chain functionalized liquid‐crystalline polymers and blends. IX.* Phase behavior and structure of comb‐shaped liquid‐crystalline ionomers containing calcium ions
Authors: Barmatov E. B. , Pebalk D. A. , Barmatova M. V. , Shibaev V. P.
Published: August 2002

Liquid‐crystalline (LC) ionomers containing 2–15 mol % calcium ions were synthesized by the exchange reaction between the nematic LC copolymer, bearing oxycyanobiphenyl mesogenic groups, and the carboxyl groups of acrylic acid, with calcium acetate. The incorporation of 2–3 mol % Ca ions in the LC copolymer leads to some rise in the clearing point and glass‐transition temperature. A further increase in the concentration of metal ions (>5 mol %) is accompanied by induction of the smectic A phase where clearing point and glass‐transition temperatures keep constant values. Phase behavior of the LC ionomers may be understood on the basis of a structural model that considers the dual role of calcium ions in a polymer matrix. Metal ions act as points of noncovalent electrostatic binding of the polymer chains and are capable of forming larger ionic associates (multiplets). The comparison of the phase behavior of sodium and calcium containing LC ionomers shows that the formation of ionic links may lead to the growth of structure defects suppressing a positive influence of charged groups on the mesophase clearing temperature. The orientation behavior of the LC ionomers in the magnetic field was studied. It was shown that the incorporation of calcium ions (3 mol %) in the LC copolymer matrix leads to the growth of orientation order parameter S of the nematic phase. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3953–3959, 2001
Heterogeneous chloroacetylation of chitosan powder in the presence of sodium bicarbonate
Authors: Jenkins David W. , Hudson Samuel M.
Published: August 2002

Because of the importance of the chloroacetyl group to carbohydrate synthesis, the objective of this work is to disclose a method that has been found useful for the heterogeneous chloroacetylation of chitosan powder in which sodium bicarbonate is used as the base for the neutralization of the acid byproduct. A series of reactions were conducted to determine the more optimal conditions under which to perform acylation. The three varied aspects of the reaction were the acylating reagent (chloroacetyl chloride and chloroacetic anhydride), the solvent (methylene chloride and N,N‐dimethylformamide), and the temperature (0 or 44 °C). According to Fourier transform infrared (FTIR), the chitosan powder being refluxed in methylene chloride in the presence of chloroacetic anhydride constituted the best conditions. By incorporating these conditions and increasing the amount of the base, we obtained a chloroacetylated chitosan powder that, characterized by FTIR, solid‐state cross‐polarity/magic‐angle spinning 13C NMR, and elemental analysis, had degrees of N‐ and O‐chloroacetylation of 0.32 and 0.15, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 4174–4181, 2001
Poly(ethylene terephthalate) copolymers containing 5‐nitroisophthalic units. III. Methanolytic degradation
Authors: Kint Darwin P. R. , de Ilarduya Antxon Martínez , Bou Jordi J. , Muñoz‐Guerra Sebastián
Published: August 2002

The methanolysis of poly(ethylene terephthalate) (PET) copolymers containing 5‐nitroisophthalic units was investigated. Random copolyesters containing 10 and 30 mol % of such units were prepared via a two‐step melt copolycondensation of bis(2‐hydroxyethyl) terephthalate (BHET) and bis(2‐hydroxyethyl) 5‐nitroisophthalate (BHENI) in the presence of tetrabutyl titanate as a catalyst. First, the susceptibility of these two comonomers toward methanolysis was evaluated, and their reaction rates were estimated with high‐performance liquid chromatography. BHENI appeared to be much more reactive than both BHET and bis(2‐hydroxyethyl) isophthalate. The methanolysis of PET and the copolyesters was carried out at 100 °C, and the degradation process was followed by changes in the weight and viscosity, gel permeation chromatography, differential scanning calorimetry, and 1H and 13C NMR spectroscopy. The copolyesters degraded faster than PET, and the rate of degradation increased with the content of nitrated units. The products resulting from methanolysis were concluded to be dimethyl terephthalate, dimethyl 5‐nitroisophthalate, ethylene glycol, and small, soluble oligomers. For both PET and the copolyesters, an increase in crystallinity was observed during the degradation process, indicating that methanolysis preferentially occurred in the amorphous phase. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 76–87, 2002
Synthesis of a novel one‐pot approach of hyperbranched polyurethanes and their properties
Authors: Hong Ling , Cui Yanjun , Wang Xinling , Tang Xiaozhen
Published: August 2002

A new method for the synthesis of hyperbranched polymers involving the use of ABx macromonomers containing linear units have been investigated. Two types of novel hyperbranched polyurethanes have been synthesized by a one‐pot approach. The structures of monomers and polymers were characterized by elemental analysis, 1H NMR, 13C NMR, Fourier transform infrared spectroscopy, gel permeation chromatography, and thermogravimetric analysis. The hyperbranched polymers have been proven to be extremely soluble in a wide range of solvents. Polymer electrolytes were prepared with hyperbranched polymer, linear polymer as the host, and lithium perchlorate (LiClO4) as the ion source. Analysis of the isotherm conductivity dependence of the ion concentration indicated that these hyperbranched polymers could function as a “solvent” for the lithium salt. The conductivity increased with the increasing concentration of hyperbranched polymers in the host polymer. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 344–350, 2002
Synthesis and structure‐property relationship of new donor–acceptor‐type conjugated monomers and polymers on the basis of thiophene and benzothiadiazole
Authors: Jayakannan M. , van Hal Paul A. , Janssen René A. J.
Published: August 2002

We have synthesized three new donor–acceptor‐type monomers to achieve soluble and processable low‐band gap polymers, 4,7‐bis(4‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole (B4TB), 4,7‐bis(3‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole (B3TB), and 4‐(3‐octyl‐2‐thienyl)‐7‐(4‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole (B34TB), by the Suzuki coupling reaction. Using B4TB and B3TB, two soluble high molecular weight regioregular head‐to‐head and tail‐to‐tail polymers poly[4,7‐bis(4‐octyl‐2‐thienyl)‐2,1,3‐ benzothiadiazole] (PB4TB) and poly[4,7‐bis(3‐octyl‐2‐thienyl)‐2,1,3‐benzothiadiazole] (PB3TB) were prepared via iron(III) chloride‐mediated oxidative polymerization. The structures of the polymers were confirmed by 1H and 13C NMR, and the molecular weights were determined by size exclusion chromatography. The optical properties (absorbance and fluorescence) of the monomers and polymers were studied and compared with unsubstituted analogues. The monomers and polymers bearing octyl substituents on the thiophene rings pointing away from the benzothiadiazole units (B4TB and PB4TB) possess a more planar structure, and their optical spectra appear redshifted as compared with those having the octyl chain nearer to the benzothiadiazole (B3TB and PB3TB). The optical band gaps of PB3BT (Eg = 2.01 eV) and PB4BT (Eg = 1.96 eV), however, are at much higher energy levels than that of the unsubstituted electrochemically polymerized PBTB material (Eg = 1.1–1.2 eV) as a result of steric effects of the octyl chains. The electrochemical properties of the monomers and polymers were examined using cyclic voltammetry and reflect the effect of alkyl substitution. B4TB and PB4TB were oxidized at a lower potential than B3TB and PB3TB, whereas their reduction potentials were less negative. The electrochemical band gap calculated from the onset of the reduction and oxidation process agreed with the optical band gap calculated from the absorption edges. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 251–261, 2002
Free‐radical crosslinking copolymerization of 2,2′‐azobis[N‐(2‐propenyl)‐2‐methylpropionamide] with vinyl benzoate resulting in polymeric azo initiators
Authors: Matsumoto Akira , Ichiryu Yoshikatsu , Aota Hiroyuki , Shiraki Kazuo , Iwata Tsutomu
Published: August 2002

2,2′‐Azobis[N‐(2‐propenyl)‐2‐methylpropionamide] (APMPA) with two carbon–carbon double bonds and an azo group was copolymerized with vinyl benzoate (VBz) at 60 °C, resulting in azo groups containing VBz/APMPA prepolymers and crosslinked polymers as soluble and insoluble polymeric azo initiators, respectively. The polymerization characteristics of APMPA as a novel diallyl monomer were clarified with the rate and degree of polymerization and the monomer reactivity ratios. The gelation behaviors in VBz/APMPA crosslinking copolymerizations were examined in detail with a comparison of the actual gel point and the theoretical gel point calculated according to Stockmayer's equation with the tentative assumption of equal reactivity for both vinyl groups belonging to VBz and APMPA. The effectiveness of the resulting branched or crosslinked poly(VBz‐co‐APMPA)s as soluble or insoluble polymeric azo initiators, respectively, at providing graft polymers through the cleavage of azo groups at an elevated temperature was examined by the polymerization of allyl benzoate at 120 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 317–325, 2002
Main‐chain viologen polymers with organic counterions exhibiting thermotropic liquid‐crystalline and fluorescent properties*
Authors: Bhowmik Pradip K. , Han Haesook , Cebe James J. , Burchett Ronald A. , Sarker Ananda M.
Published: August 2002

A series of viologen polymers with bromide, tosylate, and triflimide as counterions were prepared by either the Menshutkin reaction or metathesis reaction in a common organic solvent. Their polyelectrolyte behavior in methanol was determined by solution viscosity measurements, and their chemical structures were determined by Fourier transform infrared and Fourier transform NMR spectroscopy. They were characterized for their thermotropic liquid‐crystalline properties with a number of experimental techniques. Each of the viologen polymers with organic counterions had a low melting transition or fusion temperature above which it formed either a high‐order smectic phase or a low‐order smectic phase. Each of them also exhibited a smectic‐to‐isotropic transition. The ranges of the liquid‐crystalline phase were 80–88 °C for viologen polymers with tosylate as a counterion and 120–146 °C for viologen polymers with triflimide as a counterion. They had excellent thermal stability. The ranges of thermal stability were 288–329 °C for viologen polymers with tosylate as a counterion and 343–350 °C for viologen polymers with triflimide as a counterion. The fluorescence property for all of the viologen polymers in either aqueous or methanol solution was also included in this study. For example, the viologen polymer containing the 4,4′‐bipyridinium and p‐xylyl units along the backbone of the polymer chain with triflimide as a counterion had an absorption spectrum (λmax = 265 nm), an excitation spectrum (λex values = 357, 443, and 454 with monitoring at 533 nm), and an emission spectrum (λem = 536 nm with excitation at 430 and 450 nm) in methanol. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 659–674, 2002; DOI 10.1002/pola.10134
Bulk free‐radical photopolymerizations of 1‐vinyl‐2‐pyrrolidinone and its derivatives
Authors: White L. A. , Hoyle C. E. , Jonsson S. , Mathias L. J.
Published: August 2002

An investigation of the free‐radical bulk photopolymerization of 1‐vinyl‐2‐pyrrolidinone (NVP) with an NVP‐based crosslinker, 1,6‐(bis‐3‐vinyl‐2‐pyrrolidinonyl)hexane (BNVP), and an NVP‐based comonomer, 3‐hexyl‐1‐vinyl‐2‐pyrrolidinone (VHP), was carried out. The enthalpies of polymerization were determined for NVP and VHP to be 30.8 and 35.7 kJ/mol, respectively. The rates of polymerization were determined for NVP/VHP and NVP/BNVP systems at various temperatures. These photopolymerization studies revealed that the overall rates of polymerization of these 3‐alkylated‐2‐pyrrolidinone derivatives increased with substitution onto the pyrrolidinone ring. A series of pyrrolidinone‐based additives in bulk NVP were used in model photopolymerizations of NVP for the evaluation of plasticizer effects. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 694–706, 2002; DOI 10.1002/pola.10142
Synthesis and optical properties of soluble polyethers containing oligophenyl in the main chain and p‐styrylbenzene side groups
Authors: Spiliopoulos Ioakim K. , Mikroyannidis John A.
Published: August 2002

New polyethers containing alternating conjugated segments of p‐terphenyl or p‐quinquephenyl with p‐styrylbenzene side groups and aliphatic spacers were synthesized with pyrylium salts. They had moderate molecular weights, were amorphous, and dissolved in tetrahydrofuran, chloroform, and other common organic solvents. The glass‐transition temperatures were 68–82 and 110–153 °C for the polymers that carried p‐terphenyl and p‐quinquephenyl moieties, respectively. The absorption spectra showed a peak around 325 nm, and the band gaps were 3.27–3.34 eV, which were calculated from the onset absorption in solution. The photoluminescence maxima were at 393–398 nm in solution and 422–449 nm in thin films, indicating that the polymers were violet‐blue‐emitting materials. The photoluminescence quantum yields in solution were up to 0.25. The polymers displayed both in concentrated solutions and in the solid state intramolecular or intermolecular interactions. The polarity of the solvent influenced the shape of the photoluminescence curve. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 682–693, 2002; DOI 10.1002/pola.10151
Emulsion copolymerization of vinylidene chloride and methyl methacrylate. I. Effects of operating variables on the kinetic behavior
Authors: Nomura M. , Sakai H. , Kihara Y. , Fujita K.
Published: August 2002

The effects of operating variables on the kinetic behavior of the emulsion copolymerization of vinylidene chloride (VDC) and methyl methacrylate (MMA) were examined at 50 °C with sodium lauryl sulfate as an emulsifier and potassium persulfate as an initiator, respectively. The number of polymer particles produced increased in proportion to the 1.0 power of the initial emulsifier concentration and to the 0.3 power of the initial initiator concentration and decreased with an increasing content of MMA in the initial monomer charge. The rate of copolymerization was proportional to the 0.4 power of the initial emulsifier concentration and to the 0.5 power of the initial initiator concentration and increased with an increasing content of MMA in the initial monomer charge. The molecular weight of copolymer produced decreased drastically with an increasing content of VDC in the initial monomer charge. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1275–1284, 2002
Simultaneous construction of the polymer backbone and side chains by three‐component polycondensation: The synthesis of polyurethanes with allyl side chains from dialdehydes, alkylene N,N′‐bis(trimethylsilyl) carbamates, and allyltrimethylsilane
Authors: Niimi Lui , Serita Ken‐Ichi , Hiraoka Shuichi , Yokozawa Tsutomu
Published: August 2002

Polyurethanes with allyl side chains were synthesized by the simultaneous acid‐catalyzed reaction of dialdehydes (1), alkylene N,N′‐bis(trimethylsilyl) carbamates (4), and allyltrimethylsilane (5). When 5 was added to a mixture of 1, 4, and the catalyst, a low molecular weight polymer was formed, as well as a large amount of an insoluble gel. However, when a mixture of 1, 4, and 5 was added to the catalyst, the formation of gel was depressed, and the desired polyurethanes, consisting of 1, 4, and 5 in a molar ratio of 1/1/2, were obtained in good yields. This polyurethane synthesis is unusual in that it concurrently constructs both the polymer backbone and the functional side chains from three starting compounds. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1236–1242, 2002
Derivatization of propene/methyloctadiene copolymers: A flexible approach to side‐chain‐functionalized polypropenes
Authors: Song Fuquan , Pappalardo Daniela , Johnson Anthony F. , Rieger Bernhard , Bochmann Manfred
Published: August 2002

The copolymerization of propene with 7‐methyl‐1,6‐octadiene (MOD) catalyzed by Cp*TiMe3/B(C6F5)3 (A) and rac‐C2H4(Ind)2ZrCl2/methylaluminoxane (B) in toluene under 1 bar propene gave copolymers with unsaturated side chains. Under these conditions, catalyst A produced copolymers with an atactic backbone structure of type 1, with 3.5–19.6 mol % MOD incorporation and weight‐average molecular weight = 0.7–2.7 × 105. Using catalyst B, copolymers 2 with 0.4–3.8 mol % MOD incorporation were prepared. The comonomer incorporation was a linear function of the feed ratio. The titanium catalyst A had a significantly higher affinity for MOD than the sterically more hindered zirconocene B. Postpolymerization modification of the side‐chain CC bond allowed the facile introduction of a wide variety of functional groups. Epoxidation and especially ozonolysis of the CC bond, to give CHO and COOH functionalized copolymers, proved to be very facile routes to functionalized polypropenes. According to monitoring by NMR, most of these transformations proceed in an essentially quantitative conversion. As an example of potential applications of such polymers, polypropenes with covalently attached dyes were prepared that are suitable for blending. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1484–1497, 2002
Synthesis of a model cyclic triblock terpolymer of styrene, isoprene, and methyl methacrylate
Authors: Pantazis Dimitris , Schulz Donald N. , Hadjichristidis Nikos
Published: August 2002

The synthesis of a model cyclic triblock terpolymer [cyclic(S‐b‐I‐b‐MMA] of styrene (S), isoprene (I), and methyl methacrylate (MMA) was achieved by the end‐to‐end intramolecular amidation reaction of the corresponding linear α,ω‐amino acid precursor [S‐b‐I‐b‐MMA] under high‐dilution conditions. The linear precursor was synthesized by the sequential anionic polymerization of S, I, and MMA with 2,2,5,5‐tetramethyl‐1‐(3‐lithiopropyl)‐1‐aza‐2,5‐disilacyclopentane as an initiator and amine generator and 4‐bromo‐1,1,1‐trimethoxybutane as a terminator and carboxylic acid generator. The separation of the unreacted linear polymer from the cyclic terpolymer was facilitated by the transformation of the unreacted species into high molecular weight polymers by the evaporation of the reaction solvent and the continuation of the reaction under high‐concentration conditions. The intermediate materials and the final cyclic terpolymer, characterized by size exclusion chromatography, vapor pressure osmometry, thin‐layer chromatography, IR and NMR spectroscopy, exhibited high molecular weight and compositional homogeneity. Dilute‐solution viscosity measurements were used as an additional proof of the cyclic structure. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1476–1483, 2002
Syntheses and polymerizations of novel chiral poly(acrylamide) macromonomers and their chiral recognition abilities
Authors: Oishi Tsutomu , Lee Yong‐Kyung , Nakagawa Akira , Onimura Kenjiro , Tsutsumi Hiromori
Published: August 2002

Chiral poly(acrylamide) macromonomers (PMB‐1, PMB‐2, PPAE‐1, and PPAE‐2) were synthesized from 2‐methacryloyloxyethyl isocyanate and prepolymers, that is, poly[(S)‐methylbenzyl acrylamide] or poly(L‐phenylalanine ethylester acrylamide with a terminal carboxylic acid or hydroxy group. Radical homopolymerizations of poly(acrylamide) macromonomers were carried out under several conditions to obtain the corresponding optically active polymers. A strong temperature dependence on the specific optical rotation was observed for poly(PPAE‐2) in comparison with that for the corresponding prepolymer. This might have resulted from a change in the conformation caused by hydrogen bonds between polymer‐graft branches in the polymacromonomer. Radical copolymerizations of poly(acrylamide) macromonomers with styrene and methyl methacrylate were performed with azobisisobutyronitrile in tetrahydrofuran at 60 °C. Chiroptical properties of the copolymers were slightly influenced by comonomer units. Chiral stationary phases were prepared by the radical polymerization of poly(acrylamide) macromonomers in the presence of silica gel containing vinyl groups on the surface. Some racemic compounds such as menthol and mandelic acid were resolved on the chiral stationary phases for high‐performance liquid chromatography. The conformation based on hydrogen bonds between polymer‐graft branches in the polymacromonomers may play an important role in chiral discrimination. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1726–1741, 2002
Monomer reactivity ratios of the 2‐(3‐mesityl‐3‐methylcyclobutyl)‐2‐hydroxyethyl methacrylate and styrene system from 1H NMR
Authors: Erol Ibrahim , Soykan Cengiz , Erol Misir Ahmedzade
Published: August 2002

2‐(3‐Mesityl‐3‐methylcyclobutyl)‐2‐hydroxyethyl methacrylate (MCHEMA) was prepared from the reaction of methacrylic acid with the oxirane compound obtained from the chlorhydrin formed in the cyclization of 1‐chloro‐2,3‐epoxy‐5‐methyl‐5‐hexene. Copolymers of MCHEMA and styrene were prepared in 1,4‐dioxane solution at 60 °C using 2,2′‐azobisisobutyronitrile as the initiator. They were characterized by IR, 1H NMR, and 13C NMR spectra. Their compositions were determined by the 1H NMR technique. The monomer reactivity ratios were determined by the Fineman–Ross, Kelen, Tüdös, and Yezrielev–Brokhina–Roskin method. Thermogravimetric analysis of the copolymers was carried out under a nitrogen atmosphere. The glass‐transition temperature of the copolymers as determined by differential scanning calorimetry agreed with the Flory–Fox relationship. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1756–1763, 2002
Synthesis and properties of new hydroxyl‐pendant aromatic polyimides derived from trimethylsilylated 4,4′‐diamino‐3,3′‐dihydroxybiphenyl and aromatic tetracarboxylic dianhydrides
Authors: Imai Yoshio , Itoya Kazuo , Kanamaru Masami , Kakimoto Masa‐Aki
Published: August 2002

New phenolic hydroxyl‐pendant aromatic polyimides were synthesized with the N‐silylated diamine method in two steps: the ring‐opening polyaddition of tetrakis(trimethylsilyl)‐substituted 4,4′‐diamino‐3,3′‐dihydroxybiphenyl to various aromatic tetracarboxylic dianhydrides, giving trimethylsiloxy‐pendant poly(amic acid) trimethylsilyl esters, and thermal imidization. The hydroxyl‐bearing polyimides were amorphous but insoluble in organic solvents. They had glass‐transition temperatures greater than 370 °C and temperatures of 10% weight loss greater than 415 °C in nitrogen. The hydroxyl‐pendant polypyromellitimide film had a high tensile strength and a high modulus of 310 MPa and 10 GPa, respectively. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1790–1795, 2002
Synthesis and hydrophobic association of poly(N,N‐dimethylacrylamide) end‐functionalized with perfluorocarbon and hydrocarbon groups
Authors: Xie David , Tomczak Sandra , Hogen‐Esch Thieo E.
Published: August 2002

Polydimethylacrylamides (PDMAs) end‐functionalized with hydrophobic groups were synthesized by the reaction of cesium salts of one‐ or two‐ended living PDMA anion with octadecanoyl and perfluorooctanoyl chlorides and with α‐phenylacrylate monomers containing an octadecyl group attached via oligooxyethylene spacers to the acrylate functionality. Size exclusion chromatography or NMR studies indicated that the end functionalizations were nearly quantitative. Reduced viscosity measurements were consistent with predominantly dimeric association of the perfluorooctanoyl‐end‐functionalized PDMAs. The association of the two‐ended, perfluorooctanoyl‐ and octadecanoyl‐functionalized polymers was more extensive and consistent with pairwise association. Furthermore, the presence of oligoethylene oxide spacers between the octadecyl and α‐phenylacrylate groups greatly enhanced the hydrophobic association of bis(octadecyl)‐end‐functionalized PDMA. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1403–1418, 2001
Synthesis, characterization, and crosslinking of novel stars comprising eight poly(isobutylene‐azeotropic‐styrene) copolymer arms with allyl or hydroxyl termini. I. Living azeotropic copolymerization of isobutylene and styrene
Authors: Hull Diana L. , Kennedy Joseph P.
Published: August 2002

The overall objective of this research is the creation of novel star polymers consisting of well‐defined stable cores out of which radiate multiple poly(isobutylene‐co‐styrene) [P(IB‐co‐St)] arms whose glass‐transition temperature (Tg) can be controlled over a wide range (−73 to +100 °C) and whose arm termini are fitted with multipurpose (e.g., crosslinkable) functionalities. The first article of this series relates the synthesis and characterization of azeotropic IB/St copolymers [P(IB‐aze‐St)], which are to be subsequently used as end‐functional arms of the target stars. The P(IB‐aze‐St)s are models for statistical IB/St copolymers. The azeotropic composition is 21/79 (mol/mol) IB/St, and NMR, Fourier transform infrared, and gel permeation chromatography techniques demonstrate copolymer compositional homogeneity over the 12–96% conversion range. Conditions were developed for living azeotropic IB/St copolymerization. The livingness of the azeotropic copolymerization was proven by kinetic investigations. P(IB‐aze‐St)s with number‐average molecular weights of up to 24,000 g/mol and polydispersity indices (weight‐average molecular weight/number‐average molecular weight) less than 1.5 were prepared. The copolymerization reactivity ratios were determined: rIB = 3.41 ± 0.23 and rSt = 1.40 ± 0.26. The effect of the P(IB‐aze‐St) molecular weight on Tg was studied by DSC. Tg increases linearly with the number‐average molecular weight and reaches a plateau at 62 °C at 24,000 g/mol. The heat stability of P(IB‐aze‐St) was investigated by thermogravimetric analysis, and a 5% weight loss was found at 250 °C in air. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1515–1524, 2001
Preparing organosoluble aromatic polyimides based on 3,3′,5,5′‐tetrabromo‐2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane and aromatic dianhydrides
Authors: Hung Kuo‐Yuan , Tsiang Raymond Chien‐Chao
Published: August 2002

A new aromatic diamine, with an isopropylidene and bromo‐substituted arylene ether structure, 3,3′,5,5′‐tetrabromo‐2,2‐bis[4‐(4‐aminophenoxy)phenyl]propane, was synthesized by the nucleophilic substitution reaction of p‐chloronitrobenzene with 3,3′,5,5′‐tetrabromobisphenol A, followed by a catalytic reduction of the resulting dinitro compound. Novel aromatic polyimides with inherent viscosities ranging from 0.53 to 2.1 dL/g were then obtained by a one‐step or two‐step polymerization process with this diamine and various aromatic dianhydrides. These bromine‐containing polyimides showed typical amorphous diffraction patterns and were readily soluble at room temperature in N‐methyl‐2‐pyrrolidone, N,N′‐dimethylformamide, N,N′‐dimethylacetamide, and even in less polar solvents such as chloroform, tetrahydrofuran, and pyridine. They also dissolved in dimethyl sulfoxide, m‐cresol, o‐chlorophenol, or concentrated sulfuric acid with heating. Glass‐transition temperatures were 272–303 °C, depending on the nature of the dianhydride moiety. Thermogravimetric analysis showed that all the polymers were thermally stable, with 10% weight loss occurring between 465 and 499 °C in nitrogen and between 457 and 492 °C under atmospheric conditions. The bulky bromine substituents not only increased the solubility but also compensated for the loss of thermal properties caused by the flexible ether linkage. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1662–1674, 2001
Syntheses and characterizations of bis(trialkoxysilyl)oligoimides. II. Syntheses and characterizations of fluorinated crosslinkable oligoimides with low refractive indices
Authors: Bes L. , Rousseau A. , Boutevin B. , Mercier R.
Published: August 2002

Novel crosslinkable fluorinated oligoimides were prepared in two steps. The first involved the synthesis of oligoimides terminated with nadic or allylic double bonds, and the second step was materialized either by a radical addition of mercaptotrialkoxysilane derivatives onto nadic double bonds or a hydrosilylation reaction of hydrogenotrialkoxysilane derivative onto allylic double bonds. Three kinds of crosslinking of the trialkoxysilane end groups were studied. The first kind entailed a thermal self‐crosslinking of trialkoxysilane groups. The second process of crosslinking incorporated a bicomponent system—the crosslinked agent was 1,1,1‐tris(4‐hydroxyphenyl)ethane (TRIOH). The trialkoxysilane groups reacted with the hydroxyl–phenol groups of TRIOH to give thermally stable phenoxysilane bonds as well as a crosslinking network. The last method was also a bicomponent system; the oxalic acid was added into an oligoimide solution where by thermal treatment water was created. The water molecules hydrolyzed the trialkoxysilane groups into silanol groups that polycondensed into a crosslinked network following a sol–gel process. The mechanism of the different crosslinking reactions was investigated by Fourier transform infrared spectroscopy and solid‐state 29Si NMR. The self‐crosslinked material prepared from precursor α,ω‐trimethoxysilyl fluorinated oligomer (Mn = 5500 g · mol−1) exhibited a 10 wt % loss temperature under air higher than 420 °C and a low birefringence (Δn = 0.008) at 1.300 μm. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2602–2619, 2001
Stabilization and kinetics in the emulsion copolymerization of butyl acrylate and methyl methacrylate
Authors: Ouzineb K. , Heredia M. Fortuny , Graillat C. , Mckenna T. F.
Published: August 2002

We carried out emulsion homopolymerizations and copolymerizations of butyl acrylate (BuA) and methyl methacrylate (MMA) with different types and concentrations of surfactants to determine the influence of these parameters on the particle size and particle size distribution and to elucidate the mechanism of particle formation. As expected, the mechanisms of nucleation above and below the critical micelle concentration were very different; however, it was also found that the presence of partially soluble monomers such as MMA in the water phase had a significant influence on the critical micelle concentration of Triton X‐405 (>50%). In addition, the nucleation mechanism during copolymerization seemed to be dominated by BuA, with the number of particles per liter being very similar to the number nucleated during its homopolymerization. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2832–2846, 2001
Preparation and characterization of novel basic polysulfone polymers
Authors: Kerres Jochen , Ullrich Andreas , Hein Martin
Published: August 2002

Two synthesis routes for the preparation of novel base‐modified polysulfones (PSUs; Udel®) were investigated: (1) the addition of the basic aromatic ketones 2,2′‐dipyridylketone and 4,4′‐bis‐(diethylamino)benzophenone and the basic aromatic aldehydes N,N‐dimethylamino‐benzaldehyde, pyridine‐2‐aldehyde, pyridine‐3‐aldehyde, and pyridine‐4‐aldehyde to lithiated PSU and (2) the reaction of lithiated PSU with basic aromatic carboxylic acid esters such as 4‐N,N‐dimethylaminobenzoic acid ethylester, pyridine‐2‐carboxylic acid ethylester, pyridine‐3‐carboxylic acid ethylester, and pyridine‐4‐carboxylic acid ethylester. Both synthesis routes lead to a high degree of conversion, without the occurrence of crosslinking. This is remarkable, especially for the reaction of lithiated PSU with the ester compounds, because the (CO)Ar groups formed by the reaction of the ester with PSU–Li are not further converted with the remaining PSU–Li sites to (crosslinked) PSUC(OLi)ArPSU alcoholates, as normally observed when esters are reacted with Li‐organic compounds. Starting with dilithiated PSU, we obtained degrees of substitution of 0.8–2 groups per PSU repeating unit. The structures and compositions of the modified PSU polymers were confirmed with NMR spectroscopy and elemental analysis. The modified polymers were also characterized via thermogravimetric analysis (thermal stability). Interestingly, the product of the reaction of lithiated PSU with 4,4′‐bis‐(diethylamino)benzophenone could be oxidized to a deep blue polymeric dye that showed proton self‐conductivity. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2874–2888, 2001
End‐functionalized copolymers prepared by the addition–fragmentation chain‐transfer method: Vinyl acetate/methacrylonitrile system
Authors: Busfield W. Ken , Zayas‐Holdsworth Clovia I. , Thang San. H.
Published: August 2002

Copolymers of vinyl acetate and methacrylonitrile were prepared by free‐radical polymerization in the presence of the chain‐transfer agent (CTA) ethyl‐α‐ (t‐butanethiomethyl)acrylate. Molecular weight measurements showed that the chain‐transfer constants increased with the vinyl acetate content of the comonomer mixture, ranging from 0.42 for methacrylonitrile to 6.3 for the copolymerization of a vinyl acetate‐rich monomer mix (89/11). The bulk copolymer composition was not appreciably affected by the amount of CTA used in the copolymerization. The efficiency of the addition–fragmentation mechanism in producing specifically end‐functionalized copolymers was investigated with 1H NMR spectroscopy. Spectral peaks consistent with all the expected end groups were observed for all comonomer feeds. Peaks consistent with other end groups were also observed, and these were particularly prominent for copolymers made with lower CTA concentrations. At the highest concentrations used, quantitative measurements of end‐group concentrations indicated that 70–80% of the end groups were those expected on the basis of the addition–fragmentation chain‐transfer mechanism. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2911–2919, 2001
Synthesis and properties of poly‐(2‐ethynylpyridinium bromide) having propargyl side chains
Authors: Gal Yeong‐Soon , Lee Won‐Chul , Kim Sang‐Yul , Park Jong‐Wook , Jin Sung‐Ho , Koh Kwang‐Nak , Kim Sung‐Hoon
Published: August 2002

Poly‐(2‐ethynylpyridinum bromide) (PEPBP) having propargyl side chains was prepared by the direct polymerization of 2‐ethynylpyridine and propargyl bromide under mild reaction conditions without any initiator and catalysts. The polymerization proceeded well to give PEPBP with propargyl side chains in relatively high yields. Various spectral data for the polymer structure indicated that the conjugated polymer system having N‐propargylpyridinum substituent was formed. This ionic polymer was completely soluble in water, methanol, dimethylformamide, dimethyl sulfoxide, and N,N‐dimethylacetamide and well processable into thin homogeneous film. The photoluminescence intensity (λmax = 760 nm) of this polymer increased as the temperature was increased. At 1 KHz and room temperature, this polymer has k′ = 2.9 and σ = 7.3 × 10−10 (S/cm). © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3151–3158, 2001
Anomalous solubility of polyacrylamide prepared by dispersion (precipitation) polymerization in aqueous tert‐butyl alcohol
Authors: Guha Suparna , Ray Biswajit , Mandal Broja M.
Published: August 2002

Polyacrylamide prepared by dispersion (precipitation) polymerization in an aqueous t‐butyl alcohol (TBA) medium is only partially soluble when the TBA concentrations in the polymerization media are in the range 82 vol % < TBA < 95 vol %. Independent experiments with a soluble (linear) sample of polyacrylamide show that the polymer swells sufficiently in the aforementioned media to lower the glass‐transition temperature of the polymer below the polymerization temperature (50 °C). The anomalous solubility has been attributed to the crosslinking of polymer chains that occurs during the solid‐phase polymerization of acrylamide in the swollen polymer particles. It is postulated that some of the radical centers shift from the chain end to the chain backbone during solid‐phase polymerization by chain transfer to neighboring polymer molecules, and when pairs of such radicals come into close vicinity, crosslinking occurs. However, dispersion (precipitation) polymerization in other media such as aqueous methanol and aqueous acetone yields polymers that are soluble. This result has been attributed to the fact that the polymer radical undergoes a chain‐transfer reaction with these solvents at a much faster rate than with TBA, which overcomes the effect of the polymer‐transfer reaction. Even the addition of as little as 5% methanol to a TBA–water mixture (TBA:water = 85:10) gives rise to a soluble polymer. The chain‐transfer constants for acetone, methanol, and TBA have been determined to be 9.0 × 10−6, 6.9 × 10−6, and 1.48 × 10−6, respectively, at 50 °C. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3434–3442, 2001