bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and use of α‐methoxyphenylmethylium hexachloroantimonate as a novel initiator for the polymerization of propylene oxide
Authors: Iijima Takao , Sakamoto Yuhshi , Kakiuchi Hiroshi
Published: April 2003

α‐Methoxyphenylmethylium hexachloroantimonate was prepared from α‐methoxybenzyl chloride and antimony pentachloride at 0°C and isolated for the first time, and its visible and 1H‐NMR spectra were measured. This salt was used as a novel initiator for the polymerization of propylene oxide (PO) in the temperature range −20 to 30°C with dichloromethane as solvent. PO polymerized spontaneously but a limit yield was observed. The microstructure of PO polymer is amorphous by 13C‐NMR. The PO polymerization is thought to proceed in the conventional cationic mechanism on the basis of the polymerization behavior and the analyses of both the polymer structure and end groups attached to the PO polymer.
High‐molecular‐weight poly(p‐phenyleneterephthalamide) by CaCl2 promoted direct polycondensation with thionyl chloride in N‐methylpyrrolidone
Authors: Higashi Fukuji , Nishi Toshiharu
Published: April 2003

The direct polycondensation of terephthalic acid and p‐phenylenediamine hydrochloride (PPD.2HCl) with thionyl chloride was found to be significantly promoted in N‐methylpyrrolidone (NMP) by dissolved CaCl2 and tertiary amines. The inherent viscosity of the polymer obtained varied with the amount of CaCl2 and tertiary amines added. The reaction, when effectively promoted by CaCl2, proceeded homogeneously in the early state of polycondensation, and then resulted in a highly swollen gel. CaCl2 had to be present in the PPD.2HCl/tertiary amines/NMP solution as well as in the TPA/SOCl2/NMP mixture for the polycondensation to proceed to high molecular weight. Complexes of CaCl2, PPD.2HCl, and tertiary amines in NMP similar to the well known complex, CaCl2 · nNH3 (n = 2, 4, 8) was proposed to facilitate the polycondensation.
Preparation of poly(phenylene vinylene) from cycloalkylene sulfonium salt monomers and polymers
Authors: Lenz Robert W. , Han Chien‐Chung , Stenger‐Smith John , Karasz Frank E.
Published: April 2003

Two new types of p‐xylene bis‐sulfonium chloride monomers were prepared from cycloalkylene sulfides. The polymerization characteristics of these monomers to form poly(p‐xylene sulfonium chlorides), and the thermal elimination reactions of their polymers to poly(p‐phenylene vinylene), were compared with those of two monomers prepared from dialkyl sulfides. The cycloalkylene sulfonium chloride monomer polymerized to higher yields and to higher molecular weight polymers, which showed more efficient elimination reactions.
Functional monomers and polymers 159 synthesis and photochemical reactions of polymers containing thymine photodimer units in the main chain
Authors: Moghaddam Minoo Jalili , Hozumi Shigeo , Inaki Yoshiaki , Takemoto Kiichi
Published: April 2003

Polyamides containing thymine photodimer units in the main chain were synthesized, and their photolysis by ultraviolet irradiation below 260 nm were studied in film state. Photodimers of thymine derivatives were obtained by photochemical reaction of the carboxylic acid derivatives of thymine in aqueous solution irradiated above 270 nm. An attempt was made to resolve the isomers of the photodimers, and the two kinds of cis isomers [cis–syn(head to head), and cis–anti(head to tail)] were isolated successfully. The polyamides were prepared by condensation of the photodimers with diamine using an activated ester method. The photodissociation of the thymine photodimer in the polymer main chain caused the breakage of the polymer chains, leading to the production of oligomers and dimer compounds containing thymine bases at the ends of the molecule. The dissociation rate of the polymer did not depend on the kind of the thymine photodimer which was in the main chain of the polymer.
Polymers by the reaction of bis(pyrylium salts) with diamines: A novel approach to ionene polymers
Authors: Katritzky Alan R. , Tarr Richard D. , Heilmann Steven M. , Rasmussen Jerald K. , Krepski Larry R.
Published: April 2003

The following reactions of pyrylium salts with amines are described: (1)bis(pyrylium salts) with amines; (2) diamines with pyrylium salts; and (3) bis(pyrylium salts) with diamines. Both (1) and (2) give bis(pyridinium salts) in high yields, and (3) gives the corresponding polymers which are isolated and characterized. This procedure was applied to cationic bis(pyrylium salts) to give cationic dimers and polymers, and further to zwitterionic bis(pyrylium salts) to yield the corresponding zwitterionic dimers and polymers.
Synthesis of optically active copoly(vinylamine–vinylalcohol) containing a pair of adeninyl and thyminyl pendant groups
Authors: Lu C. X. , Xiao Chaodong , Zhu Zhijian , Ji Aixue , Overberger C. G.
Published: April 2003

Preparation of novel model polymers of polynucleotides with copoly(vinylamine–vinylalcohol) [P(Vam–Val)] backbone and a pair of adeninyl and thyminyl pendant groups is described. At first, direct, low temperature esterification was used to attach (−) and (±)‐2‐(thymin‐1‐yl)propionic acid [(−)TPA and (±)TPA], to the N–Cbz protected hydroxy polymer P(Vamz–Val) which was prepared by selective N‐protection of N‐benzyloxycarbonyloxy‐5‐norbornene‐2,3‐dicarboximide (CbzONB) with P(Vam–Val), at the hydroxy group via an ester bond. Two novel precursors P(Vamz–Ve(−)T) and P(Vamz–Ve(±)T) were obtained. Then the Cbz protecting group of P(Vamz–Ve(−)T) and P(Vamz–Ve(±)T) were removed by hydrobromic acid to give the hydrobromide salt of P(Vam–Ve(−)T) and P(Vam–Ve(±)T), respectively. Finally, the attachment of (±)‐2‐(adenine‐9‐yl)propionic acid [(±)APA] to linear P(Vam–Ve(−)T) and P(Vam–Ve(±)T) by selective N‐acylation with N‐hydroxy‐5‐norbornene‐2,3‐dicarboximide (HONB). This procedure gave the corresponding P(Vam–Val) having a pair of adeninyl and thyminyl pendant groups, such as P(Va(±)Ad–Ve(−)T) and P(Va(±)Ad–Ve(±)T). In contrast to the corresponding polymer models, the related segment model compounds were also prepared from threo‐2‐amino‐4‐pentanol without N‐blocking‐deblocking operations. The segment model compounds including four stereoisomers of highly optical purities, were separated and purified by reverse phase HPLC technique.
Living cationic polymerization of 2‐vinyloxyethyl phthalimide: Synthesis of poly(vinyl ether) with pendant primary amino functions
Authors: Hashimoto Tamotsu , Ibuki Hiroshi , Sawamoto Mitsuo , Higashimura Toshinobu
Published: April 2003

Cationic polymerization of 2‐vinyloxyethyl phthalimide (1) in CH2Cl2 at −15°C with hydrogen iodide/iodine (HI/I2) as initiator led to living polymers of a narrow molecular weight distribution (M̄w/M̄n = 1.1–1.25). The number‐average molecular weight of the polymers was in direct proportion to monomer conversion and could be controlled in the range of 1000–6000 by regulating the 1/HI feed ratio. However, when a fresh monomer was supplied to the completely polymerized reaction mixture, the molecular weight of the polymers was not directly proportional to monomer conversion. The polymerization of 1 by boron trifluoride etherate (BF3OEt2) in CH2Cl2 at −78°C gave polymers with relatively high molecular weight (M̄w > 20,000) and broad molecular weight distribution (M̄w/M̄n ∼ 2). The HI/I2‐initiated polymerization of 1 was an order of magnitude slower than that of ethyl vinyl ether, probably because of the electron‐withdrawing phthalimide pendant. Hydrazinolysis of the imide functions in poly(1) gave a water‐soluble poly(vinyl ether) (3) with aliphatic primary amino pendants.
Studies on the imidization of N‐substituted polymaleamic acids
Authors: Yang Chin‐Ping , Wang Sheng‐Sung
Published: April 2003

A spectral method for determining the imidization from maleamic acid to maleimide was described. The formation condition and mechanism of polymaleimide compared with N‐phenyl‐maleimide (I) and 4,4′‐bis(N‐maleimido)‐diphenylmethane (II) were investigated. A series of N‐substituted maleimides were synthesized by the reaction of their corresponding maleamic acids with acetic anhydride and sodium acetate as a catalyst. The rate of dehydration reaction of N‐phenylmaleamic acid with Ac2O was determined at a mole ratio 0.1:1 of NaOAc to N‐phenyl‐maleamic acid and a second‐order constant K of 1.38 × 10−2 (mL/mol s) was obtained. The activation energies for the ring‐closure reaction of N‐phenylmaleamic acid and polyphenylene‐methylenemaleamic acid were 1.26 × 104 (cal/g mol) and 1.32 × 104 (cal/g mol), respectively. The decreasing order for the rate of N‐substituted maleimide formation was N‐(p‐methylphenyl)maleimide > I ≒ II > N‐(p‐chlorophenyl)maleimide. The result was attributed to the para‐substituent effect. These imidization reaction were observed qualitatively by IR spectra and analyzed quantitatively by 1H‐NMR spectra.
Polymerization of 1‐aryl‐2‐trimethylsilylacetylenes by transition metal catalysts(II)
Authors: Gal Yeong‐Soon , Choi Sam‐Kwon , Kim Chung‐Yup
Published: April 2003

Polymerization of 1‐aryl‐2‐trimethylsilylacetylene (aryl = thienyl, furyl, and pyridyl) was carried out by transition metal catalysts. The polymer yield was generally low due to the steric hindrance. R4Sn (R = Me, n‐Bu, Ph) exhibits some cocatalytic activities with respect to polymer yield and molecular weight. On the other hand, the polymerization was decelerated when organoaluminum compounds were used as cocatalysts. The polymer yield increased in the following order: phenyl > thienyl > furyl > pyridyl, according to the aryl substituents. The NMR (1H‐ and 13C‐), IR, and UV‐visible spectra indicated that the resulting polymers have a linear conjugated polyene structure each containing the aromatic substituent and trimethylsilyl group. From 1H‐NMR integration, it was found that the resulting polymers are partially desilylated depending on the substituents of monomer and the polymerization conditions. The solubility behavior, stability and fluoride‐ion induced desilylation reaction of the polymers were also studied.
Grafting onto polypropylene II. Solvent effect on graft copolymerization of acrylonitrile by preirradiation method
Authors: Mehta I. K. , Sood D. S. , Misra B. N.
Published: April 2003

Acrylonitrile (AN) has been graft copolymerized onto isotactic polypropylene (IPP) by the preirradiation method using Co60 as the source of gamma rays in the presence of ethanol, n‐propanol, isopropanol, n‐butanol, tert. butyl alcohol, and n‐pentanol. Alcohols vary in their ability to influence grafting of AN onto IPP and the following reactivity order was found: n‐pentanol > n‐butanol > tert.‐butanol > n‐propanol > ethanol > isopropanol. An attempt has been made to explain the observed reactivity pattern shown by different alcohols. Thermal behavior of the graft copolymer has been compared with that of IPP and irradiated IPP and it was observed that grafted IPP is thermally more stable than IPP and irradiated IPP.
The effect of hindered amine light stabilizers on the photooxidative stability of high‐density polyethylene
Authors: Bigger Stephen W. , Delatycki Oskar
Published: April 2003

The photoprotective effectiveness of various polymeric and nonpolymeric hindered amine light stabilizers (HALS) was determined by exposing samples of high‐density polyethylene (HDPE) containing these additives to ultraviolet (UV) light and measuring the resultant oxygen uptake characteristics. Values of the initial quantum yield for oxygen uptake calculated for these formulations indicate that the higher molecular weight HALS compounds are less effective photostabilizers than the nonpolymeric HALS, and this is partly attributable to their decreased mobility in the polymer matrix. It was further found that the addition of an ultraviolet absorber (UVA) to a formulation containing a polymeric HALS compound enhances its photostability, although this phenomenon may be partly due to synergism between the UVA and the antioxidant, the latter having been added as part of the base stabilization. The antagonism which exists between certain sulfur‐containing antioxidants and HALS compounds was also investigated and it was found that the lower molecular weight sulfur‐containing antioxidants exhibit the greatest degree of antagonism. The results confirm that the mobility in the polymer matrix of the stabilizer system can serve as an explanation of its effectiveness. The article provides evidence that the technique of oxygen uptake monitoring is a sensitive and rapid method of assessment of polymer photostability in the presence of stabilizer systems.
The influence of the ligands on the catalytic activity of a series of RhI complexes in reactions with phenylacetylene: Synthesis of stereoregular poly(phenyl) acetylene
Authors: Furlani A. , Napoletano C. , Russo M. V. , Camus A. , Marsich N.
Published: April 2003

The catalytic activity of a series of [Rh L‐L chel]X complexes, in which we have varied the unsaturated ligand [L‐L = cis, cis‐cycloocta 1,5‐diene(cod) or 2,5‐norbornadiene(nbd) the nitrogen chelating ligand [chel = 2,2′‐bipyridine(bipy), 2,2′‐dipyridylamine(dipyam), 2,2′‐bipyrazine (bipz), 4,4′‐dimethyl‐2,2′‐bipyridine (4,4′‐Me2bipy)] and the counter ion [X = PF6, ClO4, BPh4], has been examined in reactions with phyenylacetylene (PA). The catalytic behaviour of the [Rh(cod)Cl2],tmeda (tmeda = N,N,N′,N′tetramethylethylendiamine), [Rh(cod)Cl2],teda] (teda = triethylendiamine), of the dimer [Rh(cod)Cl]2, and the use of NaOH as cocatalyst in different reaction conditions was also examined. The influence of the ligands on the catalytic activity of these RhI complexes is discussed. 1H and 13C NMR spectra have shown that highly stereoregular polyphenylacetilene can be obtained. Conditions for homogeneous doping of PPA, to obtain materials whose conductivity varies over 10–11 magnitude orders, are proposed. The stability of the doped polymers is also discussed.
Stereoselective hydrolysis of amino acid esters by dipeptide catalysts and byN‐decanoyl‐histidine in surfactant aggregate domains
Authors: Ihara Yasuji , Nakanishi Eiji , Akiyama Akemi , Yamamoto Hiroko , Nango Mamoru , Koga Joichi
Published: April 2003

The rate constants of hydrolysis of the enantiomers of amino acid nitrophenyl esters by catalytic domains composed of cationic surfactant aggregates and dipeptide catalysts orNdecanoyl‐L‐histidine have been determined at pH 7.30. The dipeptide catalysts shows large rate enhancement and stereoselectivity in aggregate domains. The surfactant structural effects are examined by investigation of the rate constants and stereoselectivities, and the nature of stereoselective catalysis is discussed.
Synthesis of optically active polynucleotide analogs with polytrimethylenimine backbones and thymine moieties
Authors: Overberger C. G. , Chang Ji Young , Gunn V. E.
Published: April 2003

Polynucleotide analogs with polytrimethylenimine backbones and optically active 2‐(thymin‐1‐yl)propionic acids as pendants were prepared. Linear polytrimethylenimines were obtained by ring‐opening polymerization of 2‐phenyl‐5,6‐dyhydro‐4H‐1,3‐oxazine and subsequent hydrolysis of the resulting polymers. 2‐(Thymin‐1‐yl)propionic acids were reacted with N‐hydroxy succinimide to form active esters. Optical purities of active esters were determined by NMR with chiral chemical shift reagents. The polynucloetide analogs and related monomer and dimer model compounds were prepared by grafting reactions using active esters.
Seeded polymerization of vinyl acetate using monodisperse poly(vinyl acetate) latex particles
Authors: Hayashi Sadao , Komatsu Akihiko , Hirai Toshihiro
Published: April 2003

The seeded polymerizations of vinyl acetate, using monodisperse poly(vinyl acetate) latex particles prepared in the absence of emulsifiers with potassium persulfate, have been investigated at 70°C with potassium persulfate as an initiator. New small particles were formed in the system containing a small amount of seed particles, but were not observed in the system containing a large amount of seed particles. The size of the secondary particles increased, and their number decreased, with an increase in the seed particle number. The minimum diameter of PVAc particles, which are stabilized by the sulfate ion groups bound at the end of polymer chains during polymerization, was determined to be 0.12 μm diameter from the limiting total surface area of seed particles which prevented further secondary nucleation. The minimum diameter of the particles increased as the speed of the stirrer increased. The new small particle number calculated using this value agreed well with that formed in the seeded polymerization.
Poly(enamine‐ketones) from hydrogen‐terminated aromatic dipropynones and aromatic diamines
Authors: Bass R. G. , Sinsky M. S. , Connell J. W. , Waldbauer R. O. , Hergenrother P. M.
Published: April 2003

Poly(enamine‐ketones) were prepared by the nucleophilic (Michael‐type) addition of various aromatic diamines to 1,1′‐(1,3‐ or 1,4‐phenylene)bis(2‐propyn‐1‐one)(1,3 or 1,4‐PPO) in m‐cresol at 5–23°C. The low molecular weight polymers (inherent viscosity of 0.25 dL/g) exhibited limited solubility in organic solvents. Glass transition temperatures were generally undetectable by differential scanning calorimetry while polymer decomposition temperatures (10% weight loss), as measured by thermogravimetric analysis, were observed from 355 to 419°C. Polymers prepared from 1,4‐PPO were semi‐crystalline as shown by wide‐angle X‐ray diffraction. The poly(enamine‐ketone) structure was confirmed by matching infrared spectral characteristics of the polymers with those of well‐characterized model enamine ketones.
Effect of ureas on the viscometric behavior of water‐soluble isotactic poly(2‐hydroxyethyl methacrylate)
Authors: Jeon Sang Il , Jhon Mu Shik
Published: April 2003

Isotactic poly(2‐hydroxyethyl methacrylate) (PHEMA) is soluble and has the compact random coil structure in water solution. The effect of six ureas (thiourea, urea, methylurea, ethylurea, 1,3‐dimethylurea, and tetramethylurea) on the viscometric behavior of aqueous solutions of isotactic PHEMA as a function of urea concentrations at 25°C has been investigated. The compact random coil structure is found to disappear as ureas are added. The result is discussed in terms of water structure breaking and making effect of solutes, and hydrophobic interactions. In addition, experiments were performed with aqueous isotactic PHEMA solutions at four different temperatures. Isotactic PHEMA in pure water has the most compact conformation at 20°C.
Synthesis of polymer materials by low energy electron beam. VIII. Formation mechanism of microporous urethane‐acrylamide film
Authors: Ando Masayuki , Goto Takakazu , Tsuchiya Mitsuru , Uryu Toshiyuki
Published: April 2003

The formation mechanism of microporous film which was obtained by casting a methyl ethyl ketone (MEK)/N,N‐dimethlformamide (DMF) solution of an electron beam (EB)‐reactive urethane‐acrylamide prepolymer was discussed. The porosity and crystallinity increased with increasing DMF content in the solvent mixture. This correlation was explained by a progressive slight coagulation and nucleation of the prepolymer due to the difference in volatility between MEK and DMF. As the result, when the DMF content reached 25 vol%, micropores were formed throughout the film. Such a mechanism was supported by the localization of the acrylamide groups at the surface which was induced by the crystallization and by the interaction of amide groups with DMF. The polymerization of acrylamide groups by EB could fix the microporous morphology.
Synthesis and photo‐induced dissolution of polymers bearing imino sulfonate groups
Authors: Shirai Masamitsu , Tsunooka Masahiro , Tanaka Makoto , Nishijima Kanji , Ishikawa Katsukiyo
Published: April 2003

Novel photosensitive polymers were synthesized by the copolymerization of methyl methacrylate and 1,2,3,4‐tetrahydro‐1‐naphthylideneimino p‐styrenesulfonate (NISS) and by the ternary polymerization of methyl methacrylate, methacrylic acid, and 9‐fluorenylideneiminop‐styrene‐sulfonate (FISS). NISS and FISS units showed good sensitivity to light of wavelengths below 300 nm and below 366 nm, respectively. Although the polymers were insoluble in aqueous alkaline solutions, on irradiation with UV light they became soluble in aqueous alkaline solutions. A remarkable decrease in molecular weight of the polymers was observed during the photolysis of imino sulfonate groups incorporated into the polymers, which assisted the dissolution of the irradiated polymers.
The synthesis, characterization, and polymerization of 1‐ethyl‐4‐[(2‐methacryloxy)ethyl carbamoyloxymethyl]‐2,6,7‐trioxabicyclo[2.2.2]octane
Authors: Herweh J. E.
Published: April 2003

The synthesis of a monomer bearing polymerizable acrylic and bicyclic ortho ester groups is described. The monomer 1‐ethyl‐4‐[(2‐methacryloxy)ethyl carbamoyloxymethyl]‐2,6,7‐trioxabicyclo[2.2.2]octane is characterized by elemental analysis, 1H‐ and 13C‐NMR spectra, mass spectra, and heat of polymerization. The free‐radical and ionic polymerization of 4 is probed as is its copolymerization with several vinyl monomers.
Determination of the reactivity parameters for the copolymerization of butyl acrylate with vinyl acetate
Authors: Bataille P. , Bourassa H.
Published: April 2003

The composition of vinyl acetate–butyl acrylate copolymers obtained with batch emulsion polymerization have been studied by 1H‐NMR. Using the integrated copolymerization Meyer–Lowry equation, the apparent reactivity ratios of the two monomers were calculated as 10.67 for r1, the reactivity ratio of butyl acrylate (BA), and 0.024 for r2, the reactivity ratio of vinyl acetate (VAC). These results were compared with those obtained by other methods.
Synthesis and characterization of certain new poly(bisimide)s. I
Authors: Nanjan M. J. , Sivaraj K.
Published: April 2003

Maleic and citraconic anhydrides were reacted with several diamines to obtain a novel class of high temperature resistant bisimides.1–3 The bisimides were characterized by melting points, elemental analysis, UV–Vis, 1H‐ and 13C‐NMR, and mass spectral analysis. The bisimide monomers were then polymerized by the addition process. A poly(amidemaleimide) was also synthesized by reacting maleic anhydride with p‐aminobenzhydrazide. The thermal stability of these highly crosslinked poly(bisimide)s were examined by TGA and DTA. A neat bisimide monomer obtained from 2,2′‐bis[4(p‐aminophenoxy)phenyl] propane with maleic anhydride namely, 2,2′‐bis[4‐(p‐maleimidophenoxy)phenyl]propane was reacted with 2,2′‐bis[4(p‐aminophenoxy)phenyl]propane by the Michael reaction.4 A fiber glass cloth reinforced laminate was prepared from bismaleimide and amine mixture and the mechanical properties of the test laminate evaluated.
Catalyzed degradation of poly(vinylchloride). III. Zinc(II) chloride catalysis
Authors: Owen Eryl D. , Msayib Kadhum J.
Published: April 2003

When PVC films containing zinc(II) chloride were heated in the temperature range 65–95°C, broad absorptions developed in the 250–900 nm region with maxima around 610 nm. The development of the color, the rate of which was proportional to the ZnCl2 content, was preceded by an induction period, the length of which depended on the temperature. The activation energy of the process decreased as the ZnCl2 content of the film increased. Color developments in air and in vacuum were compared.
A comparative account of properties of novel unsaturated polyesters synthesized by different polyesterification processes
Authors: Agrawal J. P. , Chouk M. P. , Satpute R. S. , Bhale V. C.
Published: April 2003

NUP‐7(II) has already proved its potential for inhibition of CMDB propellants. NUP‐7(I), NUP‐7(II), and NUP‐7(III) have been synthesized by “one‐step,” “two‐step,” and “three‐step” processes of polyesterification and their various characteristics have been studied and discussed in terms of theoretical considerations. NUP‐7(III) possesses better elongation and higher chemical resistance (low nitroglycerine absorption)—two contradictory characteristics reported in the case of most of the polymeric materials. It therefore will have added advantages over NUP‐7(II) for military as well as civil applications.
Copolyamides of nylon‐4,6 and nylon‐4,T
Authors: Gaymans R. J. , Aalto S. , Maurer F. H. J.
Published: April 2003

Copolyamides of nylon‐4,6 and nylon‐4,T were prepared by a two‐step method: (1) a prepolymerization in an autoclave (40 min at 210°C) and (2) a postcondensation in the solid state (4 h, 260°C). On these materials was studied the melting behavior with DSC, the crystalline structure with WAXS, the water absorption, and the mechanical properties with a torsion pendulum. In these copolyamides the order was found to remain high, but the crystalline structures of ‐4,6 and ‐4,T were not isomorphous. The torsion moduli increased with ‐4,T content both at RT and at 140°C.
Conducting polymers. I. Electrical conductivity of poly(bis‐p‐phenylenediaminosulphoxide)
Authors: Ghander A. M. , El‐Sonbati A. Z. , Diab M. A.
Published: April 2003

Poly(bis‐p‐phenylenediaminosulphoxide) was prepared by Michael addition of p‐bis‐N‐sulphinylphenylenediamine with p‐phenylenediamine at 150°C. Thermal and electrical behaviors of the polymer have been studied. The polymer is found to have increased conductivity possibly due to the participation of lone pairs of electrons on nitrogen and sulphur atoms with σ bond of the macrochain. Thermogravimetric analysis indicates that the polymer is fairly stable than other conducting polymers up to 200°C. The activation energy of the polymer was measured and found to be 13 kcal mol−1.
Synthesis and characterization of liquid crystalline polyacrylates and polymethacrylates containing benzyl ether and diphenyl ethane based mesogens
Authors: Hsu Chain S. , Percec Virgil
Published: April 2003

The synthesis and radical polymerization of a novel series of acrylates and methacrylates containing p‐cyanophenyl‐p‐hydroxybenzyl ether, p‐methoxyphenyl‐p‐hydroxybenzyl ether, and 1‐(p‐cyanophenyl)‐2‐(p‐hydroxyphenyl) ethane groups attached to the polymerizable group through aliphatic spacers containing 11 and 6 methylenic units is described. The resulting polymers were characterized by differential scanning calorimetry and optical polarization microscopy. All polymers exhibited enantiotropic mesomorphism. Low molar mass compounds based on benzyl ether or diphenyl ethane units exhibit only monotropic or virtual transitions. This demonstrates that the “polymer effect” stabilizes mesophases obtained from “mesogenic units” which do not contain rigid interconnecting groups.
Chemical release control: Carbamates of 3‐vinylphenyl and 2‐methacryloyloxyethyl isocyanates and perfume and herbicide alcohols
Authors: Kamogawa Hiroyoshi , Kohno Hiroyuki , Kitagawa Rikiya
Published: April 2003

Polymerizable carbamates were synthesized from 3‐vinylphenyl and 2‐methacryloyloxyethyl isocyanates and perfume and herbicide alcohols, such as 2‐phenethyl alcohol, citronellol, geraniol, 1‐menthol, borneol, and 2‐(2,4‐dichlorophenoxy)‐ and 2‐(2,4,5‐trichlorophenoxy)ethyl alcohols. Copolymerization of these carbamate monomers and N‐vinyl‐2‐pyrrolidone with AIBN in dioxane gave respective copolymers. Hydrolyses of both monomers and copolymers, however, required severe acid conditions, although different chemical structures gave different hydrolytic behaviors.
Coordination structure and magnetic property of poly(pyridilenemethylidenenitriloiron)s
Authors: Nishide Hiroyuki , Yoshioka Naoki , Tsuchida Eishun , Inoue Hidenari
Published: April 2003

Poly[bis(2,6‐pyridinediylmethylidenenitrilohexamethylenenitrilomethylidene)iron sulfate] was said to be a ferromagnetic compound by earlier investigators. This polymer and its derivatives are carefully reprepared and their unusual magnetic property is reinvestigated spectroscopically. The counter anion species and spacer length of the polymers affect their coordination structure and magnetism. Mössbauer spectroscopy and x‐ray diffractometry on the polymers indicate that their unusual magnetic property is caused by the ferromagnetic iron oxide slightly formed in the polymers.
Direct polyamidation with phosphorus oxychloride in pyridine
Authors: Higashi Fukuji , Kobayashi Akira
Published: April 2003

Direct polycondensation of aromatic dicarboxylic acids and diamines with phosphorus oxychloride (POC) was successfully carried out to give polyamides of high inherent viscosity, when POC was reacted selectively and completely with a two molar quantity of carboxyl groups. To achieve the selective and complete reaction, factors, such as the amount of POC used, reactions of POC with the dicarboxylic acids by adding of POC to the acids or its reverse addition under various conditions, and aging after addition were fully examined. The reaction was proposed to proceed via a bifunctional cyclic phosphoric–carboxylic anhydride through stepwise reaction of POC with carboxyl groups.
Study of the synthesis of poly(isobutylene‐b‐amide‐11) by polycondensation α,ω‐dianhydride oligoisobutylene with α,ω‐diamino oligoamide‐11. II. Synthesis of the block copolymers by reaction in solution
Authors: Tessier Martine , Marechal Ernest
Published: April 2003

Several di‐, tri‐ or multiblock poly(isobutylene‐b‐amide‐11)s are prepared by reaction of α‐mono or α,ω‐dianhydride oligoisobutylenes with α‐mono or α,ω‐diamino oligoamides, in o‐dichorobenzene at 140°C. They are characterized mainly by 1H‐ and 13C‐NMR spectroscopy and GPC, using the trifluoroacetylation technique. Their thermal differential chromatograms are reported and analyzed.
Binding of butyl orange by poly(2‐dimethylaminoethyl methacrylate) and copolymers of 2‐dimethylaminoethyl methacrylate and N‐vinyl‐2‐pyrrolidone: Peculiar temperature dependence of the binding
Authors: Kozuka Hiroshi , Hosokawa Toshitsugu , Takagishi Toru
Published: April 2003

The temperature dependence of the binding of butyl orange by a homopolymer of 2‐dimethylaminoethyl methacrylate (DMAEMA) and copolymers of DMAEMA and N‐vinyl‐2‐pyrrolidone (VPy) has been examined at various pH's. The binding is very much dependent upon the temperature of the system, the pH of the binding medium, and the DMAEMA content in the polymer. In this case maximal binding is obtained at approximately 15–25° in the temperature range measured, although in most cases which have been examined, the degree of binding increases steadily with increasing temperature. This peculiar temperature dependence of the binding becomes more pronounced as the pH and the DMAEMA content are increased. The appearance of the peculiarity is discussed in terms of the pH‐induced conformational changes of the polymer and the hydrophobicity of the polymer.
Adenine and thymine grafts on polyethyleneimine
Authors: Smith Walter T. , Kluttz William F. , Palmieri Donna , Butterfield D. Allan
Published: April 2003

Graft polymers of three different molecular weights of polyethyleneimine (PEI) with 9‐(vinylsulfonylethyl) (9‐VSE)‐adenine and 1‐(vinylsulfonylethyl) (1‐VSE)‐thymine were prepared. PEI's having molecular weights of 600, 1200, and 1800 were used and various ratios of VSE‐nucleobases to ethyleneimine were employed in the grafting process. As expected, a decrease in the nucleobase substitution in the resulting graft polymer resulted in an increase in its water solubility. The degree of substitution in the graft polymers was calculated from sulfur determinations: in most cases this degree of substitution indicated that not all of the VSE derivative has reacted with the PEI due to the highly branched nature of the latter. The presence of nucleobase stacking in the polymers was studied by UV spectroscopy. Stacking was observed for the adenine polymers in both DMSO and 0.1N HCl while stacking in the thymine polymers was observed in 0.1N HCl but not in DMSO. The absence of stackingwithin the thymine polymers in DMSO was attributed to complexation of primary amino groups of the PEI backbone with the pyrimidine ring.
Co‐oligomerization of ethylene and higher linear alpha olefins. II. Olefin reactivities in various reaction steps of co‐oligomerization with nickel ylide‐based system
Authors: Kissin Y. V.
Published: April 2003

Part I described co‐oligomerization reactions of ethylene and various linear α‐olefins (propylene, 1‐butene, 1‐hexene, 1‐heptene, 1‐octene, and 1‐decene) in the presence of the homogeneous catalyst consisting of sulfonated nickel ylide and diethylaluminum ethoxide. The present article analyzes olefin reactivities in various reaction steps of the co‐oligomerization reactions as well as reactivities of various catalytic species. Chain propagation reactions (insertion into the NiC bonds) with participation of α‐olefins exhibit poor regioselectivity, primary insertion being ca. 60% more probable than the secondary insertion. Ethylene is significantly more reactive in chain propagation reactions: 50–70 times compared to olefin primary insertion and 100–120 times compared to olefin secondary insertion. Reactivities of α‐olefins in chain propagation reactions decrease slightly for higher olefin alkyl groups. Reactivities of NiC bonds in chain propagation and chain termination reactions strongly depend on the structure of the alkyl group attached to the nickel atom. The NiCHRCH2R bond has very low reactivity in ethylene insertion reaction and usually decomposes in the α‐hydrogen elimination process. Kinetic analysis of olefin co‐oligomerization reactions provides numerous analogies with olefin copolymerization reactions in the presence of Ziegler–Natta catalysts.
Anionic polymerization of lactones initiated by alkali graphitides. IV. Copolymerization of ε‐caprolactone initiated by KC24
Authors: Gitsov Ivan , Rashkov Iliya Bl. , Panayotov Ivan M. , Golub′ Alexandr
Published: April 2003

The copolymerization of ε‐caprolactone (ε‐CL) with octamethylcyclotetrasiloxane (D4) and styrene (St) under the action of the second‐stage potassium graphitide KC24 was investigated. The copolymerizations were carried out in bulk or in xylene at 20°C. The content of the block copolymer ε‐CL/D4 in the polymerization mixture was 60–95%, the molecular weight ranging between 150,000 and 300,000. The data for the copolymers' composition obtained by 1H‐NMR and GPC showed 14–20% of D4‐units in the copolymer. The amount of the block copolymer ε‐CL/St in the polymerization products was 0–87%, and the molecular weights in the case of copolymer formation were between 100,000 and 500,000. The content of St‐units in the copolymers was from 10 to 75% as shown by GPC and 1H‐NMR. The mechanism of action of the initiator is discussed.
Relative reactivity of primary and secondary amine hydrogen atoms in the reaction between aniline and phenyl glycidyl ether: The effect of ethanol and other additives and the modifying effect of benzene as solvent
Authors: Johncock P.
Published: April 2003

The relative reactivity ratio (k2/k1) for the secondary and primary amine hydrogen atoms in the neat reaction between aniline and phenyl glycidyl ether was 0.30. This is significantly lower than a recently reaffirmed random value of 0.5 for this system. The ratio is sensitive to added ethanol and decreased with increasing concentration to a limiting value of about 0.20. With benzene as solvent, the effect of added ethanol was more complex, and a low concentration provided a value of 0.45 which decreased with increasing concentration. Other hydroxy additives behaved similarly, but boron trifluoride appears to have no effect on this ratio.
Polyimides from 4,4′‐(alkylene‐α,ω‐dioxy) bis(phenylsuccinic anhydride)s and bis(phenylglutaric anhydride)s
Authors: Teshirogi Takuma
Published: April 2003

4,4′‐(Alkylene‐α,ω‐dioxy)bis(phenylsuccinic anhydride)s and bis(glutaric anhydride)s were obtained by the condensation of 4,4′‐diformyl‐α,ω‐diphenoxyalkanes with ethyl cyanoacetate followed by the addition of potassium cyanide or meldrum acid (2,2‐dimenthyl‐1,3‐dioxane‐4,6‐dione), hydrolysis with concentrated hydrochloric acid, and dehydration with acetic anhydride. Alkylene groups were ethylene, trimethylene, and tetramethylene. Polyimides were prepared from these anhydrides with 4,4′‐diaminodiphenyl ether, 4,4′‐diaminodiphenyl sulfide, and 4,4′‐diaminodiphenylmethane through thermal ring closure of polyamic acids obtained by solution polymerization in dimethylacetamide, and thermal stability of these polyimide film was examined by thermogravimetric analysis.
Synthesis of polyphenylene ether and thioether ketones
Authors: Durvasula V. R. , Stuber F. A. , Bhattacharjee D.
Published: April 2003

The known polymerization of 4,4′‐difluorobenzophenone (DFB) with the dianion of hydroquinone to poly(phenylene ether ether ketone) (PEEK) and polymerization of either DFB with the dianion of 4,4′‐dihydroxybenzophenone or self polycondensation of the anion of 4‐hydroxy‐4′‐fluoro‐benzophenone to poly(phenylene ether ketone) (PEK) were studied in N‐cyclohexyl‐2‐pyrrolidone (CHP), which is a high‐boiling aprotic polar solvent. The formation of high‐molecular weight PEEK and PEK in this solvent was very efficient. The reactivity in CHP can be ascribed to effective solvation of metal ions rendering the anion very reactive toward nucleophilic substitution. The polymerization was extended to 4,4′‐bis(4‐fluorobenzoyl)diphenyl ether and 1,4‐bis[4‐(4‐fluorobenzoyl)phenoxy]benzene to give a high molecular weight polymer with PEK and PEEK repeating units and PEEK respectively. The polymerization of DFB with purified anhydrous sodium sulfide in CHP gave rapidly a high molecular weight poly(phenylene ketone sulfide) (PKS). In contrast, diphenyl sulfone (DPS) was not very effective in obtaining such a high molecular weight PKS even with prolonged heating, which suggests the uniqueness of CHP in promoting a high degree of polymerization.
Photochromism of spirofluorenylindolizines
Authors: Deblauwe Veerle , Smets Georges
Published: April 2003

The decoloration kinetics of three spirofluorenylindolizines have been followed in solution and in polymer matrix. They are the 5′‐methyl‐spiro[9H‐fluorene‐9.1′(1′H)‐indolizine]‐2′‐3′‐bis‐methoxycarbonyl (I), its methacryloyl oxymethyl (II) derivative, and the copolymers of (II) with ethyl acrylate. In solution the reactions follow first‐order kinetics and show pronounced negative solvatochromism. In solid polymer film, the incorporation of the photochrome as side group of polyethylacrylate affects strongly the decoloration below Tg of the film. Above Tg the decoloration was interpreted on the basis of the WLF equation.
Microemulsion polymerization of styrene
Authors: Guo J. S. , El‐Aasser M. S. , Vanderhoff J. W.
Published: April 2003

Initiation of polymerization in styrene oil‐in‐water microemulsions by water‐soluble potassium persulfate of oil‐soluble 2,2′‐azobis‐(2‐methyl butyronitrile) at 70°C gave stable latexes which were bluish and less translucent than the original microemulsions. The effects of initiator concentration, polymerization temperature, and monomer concentration on the kinetics, particle size distributions, and molecular weight distributions were investigated. The kinetics of polymerization were measured by dilatometry. In all cases, the polymerization rate shows only two intervals, which increased to a maximum and then decreased. There was no apparent constant rate period and no gel effect. A longer nucleation period was found for polymerizations initiated by potassium persulfate as compared to 2,2′‐azobis‐(2‐methyl butyronitrile). The small latex particle size (20–30 nm) and high polymer molecular weight (1–2 × 106) implies that each latex particle consists of two or three polystyrene molecules. The maximum polymerization rate and number of particles varied with the 0.47 and 0.40 powers of potassium persulfate concentration, and the 0.39 and 0.38 powers of 2,2′‐azobis‐(2‐methyl butyronitrile) concentration, respectively. This is consistent with the 0.4 power predicted by Smith–Ewart Case 2 kinetics. Microemulsion polymerizations of styrene–toluene mixtures at the same oil‐water phase ratio gave lower polymerization rates and lower molecular weights, but the same latex particle size as with styrene alone. A mechanism is proposed, which comprised initiation and polymerization in the microemulsion droplets, by comparing the kinetics of microemulsion polymerization with conventional emulsion and miniemulsion polymerization systems.
Radical‐initiated homopolymerization and copolymerization of ethyl α‐hydroxymethylacrylate
Authors: Ueda Mitsuru , Koyama Toshitaka , Mano Motokazu , Yazawa Masahiko
Published: April 2003

Ethyl α‐hydroxymethylacrylate (EHMA) was synthesized and homopolymerized in bulk and in solution. The poly(EHMA) is readily soluble in alcohol, acetone, tetrahydrofuran, and methylene chloride at room temperature. Intramolecular lactone formation occurred when poly(EHMA) was heated to 180–230°C. The kinetics of EHMA homopolymerization was investigated in ethyl acetate, using α,α′‐azobisisobutylonitrile as an initiator. The rate of polymerization Rp was expressed by Rp = k[AIBN]0.50[EHMA]1.4 and the overall activation energy was calculated as 71.9 kJ/mol. Kinetic constants for EHMA polymerization were obtained as follows: kp/k = 0.17L0.9mol−0.9s−0.5; 2fkd = 1.5 × 10−5 s−1. The relative reactivity ratios of EHMA(M2) copolymerization with styrene (r1 = 0.472, r2 = 0.564) in ethyl acetate were obtained. Applying the Q‐e scheme led to Q = 0.84 and e = 0.35 for EHMA.
Structure and morphology of the 60/40 poly(p‐oxybenzoate‐co‐ethylene terephthalate) copolymer
Authors: Quach L. , Hornbogen E. , Volksen W. , Economy J.
Published: April 2003

The copolyester composed of 60 mol% p‐hydroxybenzoic acid and 40 mol% ethylene terephthalate has been studied extensively by earlier workers. However, some confusion exists particularly with respect to the nature of the thermal transitions and the possible presence of additional phases. In the present study we have examined this copolyester and found that it is possible to separate the material into soluble and insoluble fractions with significantly different ratios of p‐hydroxybenzoic acid to ethylene terephthalate. In fact, the soluble PET‐rich fraction is blocky in nature, while the PHBA‐rich fraction is more random. The multiple thermal transitions can now be readily interpreted in terms of a heterogeneous composition which tends to segregate and phase separate.
Plasma polymerization of ethylene glycol monomethylether and water‐vapor permeability
Authors: Inagaki N. , Kubokawa Y.
Published: April 2003

Plasma polymerization of ethylene glycol monomethylether (EGMME) was investigated by elemental analysis, infrared spectroscopy, and ESCA. The surface and permeation properties for the formed polymers were discussed. EGMME was plasma‐polymerized to yield films. The films contained a large amount of oxygen‐containing groups such as hydroxy, carbonyl, carboxylate ester, and ether groups. The formation of polymers having hydroxy groups was favorable in plasma polymerization at low W/FM values. Their surface energy was high (63.2–57 dyn/cm) and decreased with increasing the W/FM value. The plasma‐polymers from EGMME had slightly high water‐vapor permeability and low oxygen and nitrogen permeabilities. The plasma‐polymers, conclusively, are characterized to have high selectivity in water‐vapor permeation.
Studies on polymerization of vinyl acetate using ylide as an initiator and degradative transfer agent
Authors: Shukla A. K. , Saini S. , Kumar P. , Rai J. S. P. , Srivastava A. K.
Published: April 2003

Polymerization of vinyl acetate initiated by β‐picolinium p‐chlorophenacylide was carried out at 30, 35, and 40°C, using conventional dilatometric technique. The initiator and the monomer exponent values were 0.80 ± 0.15 and unity, respectively. The polymerization was inhibited in the presence of hydroquinone, but was favored by nonpolar solvent and polymerization temperature. The energy of activation was 90.3 KJ mol−1. An average value of k/kt for the present system was found to be 0.37 × 10−2. The results are explained in terms of a radical mode of polymerization with degradative initiator transfer; the principal mode of termination, however, was bimolecular.
Study on the feasibility of TLC/FID to reveal chemical composition distributions of copolymers obtained by emulsion processes
Authors: Tacx J. C. J. F. , German A. L.
Published: April 2003

The CCD (chemical composition distribution) of poly(styrene‐co‐ethyl methacrylate) has been determined by thin layer chromatography/flame ionization detection (TLC/FID). It appeared that a mixture of five reference copolymers obtained by solution polymerization each having a narrow CCD, could be separated in five distinct peaks, provided a modified spotting procedure and a concentration gradient elution technique were applied. All copolymers prepared by solution polymerization could be successfully characterized. Copolymers obtained by emulsion techniques using nonionic or anionic surfactants containing oxyethylene groups, or in the absence of chain length modifier behaved anomalously and appeared to have spurious CCD's. Also the average composition calculated from these CCD's did not agree with the average composition determined by 1H‐NMR. This anomalous behaviour disappeared when using sodium lauryl sulfate as surfactant or when applying a chain length modifier (n‐dodecyl mercaptan) during the preparation of the polymer. Several possibilities have been proposed in order to explain these phenomena. The most probable explanation seems to be reaction of a growing polymer chain with surfactant molecules resulting in a quasi‐terpolymer. This polymer containing highly polar oxyethylene groups, remains strongly adsorbed on the silica surface during elution, thus disturbing the separation process.
Polymerizable tautomers. VI. Solvent effects on polymerization and copolymerization of ethyl 4‐methyl‐3‐oxo‐4‐pentenoate
Authors: Masuda Seizo , Tanaka Masami , Ota Tadatoshi
Published: April 2003

The radical polymerization of ethyl 4‐methyl‐3‐oxo‐4‐pentenoate (EMAA) was investigated at 60°C in benzene and acetonitrile. In both solvents, the kinetic results disagreed with the conventional model of radical polymerization. A remarkable solvent effect on monomer reactivity ratio was observed for the copolymerization of EMAA and styrene. Regression analysis of the monomer reactivity ratio with the solvatochromic parameters gives a good linear relationship, taking into account polarity and hydrogen‐bond donating acidity of the solvent as the major factors.
Polymerization of 2,6‐diarylphenols
Authors: Hay A. S. , Dana D. E.
Published: April 2003

The oxidative polymerization of 2,6‐diarylphenols that contain substituents (CH3, OCH3, and, ‐phenyl) in the para positions of the pendant phenyl groups is described. Copolymers of these phenols with 2,6‐diphenylphenol and blends of the polymers have also been studied.
Preparation and characterization of plasma‐polymerized N‐vinyl‐2‐pyrrolidone films
Authors: Marchant R. E. , Yu D. , Khoo C.
Published: April 2003

Thin films (< 1 μm) of plasma polymerized N‐vinyl‐2‐pyrrolidone (PPNVP) have been prepared, using an inductively coupled RF glow discharge in a flow‐through reactor system. PPNVP films were hydrophilic, smooth, and appeared morphologically homogeneous. The polymer deposition rate was found to increase linearly with NVP flow rate, and to decrease with the distance from the induction coil. ATR–FT–IR spectral studies suggested a highly branched polymer structure and included absorptions at 2150 and 1540 cm−1 which were unique to the plasma polymer and derived from lactam ring opening/breaking reactions. ESCA studies demonstrated that, under a given set of plasma reaction conditions, the surface composition was consistent throughout the reactor. However, polymer composition was influenced by larger changes in the plasma energy, since the nitrogen content was found to decrease with increasing W/FM. This corresponded to concomitant increases in the advancing water contact angles and to small but reproducible changes in the IR spectrum.