bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of an absolute X‐ray method for the determination of the crystalline fraction of a series of polymers
Authors: Martuscelli Ezio , Martynov Michael A. 
Published: April 2003

AbstractAn absolute X‐ray method for the determination of the crystalline fraction in polymers based on the comparison of the integrated intensities of some of the low order lines of polymers with those of the completely crystalline standard substances, is described. The crystallinity data are obtained for six polymers: 45.6% for isotactic polypropylene, 73% for polyethylene, 52.1% for nylon‐6, 50.8% for nylon‐66, 32% for isotactic polystyrene, and 33.4% for poly‐4‐methylpentene‐1.These data are in a reasonable agreement with the data obtained by the other X‐ray procedures. The accuracy of the method, however, is restricted by the general impossibility to know precisely the structure factors and the corrections to the intensities due to the thermal vibrations of the atoms and lattice imperfections.
Graft‐polymerization of styrene on polyethylen single crystals
Authors: Iguchi Masatoshi , Kōyama Yukihiko , Tonami Hiroaki , Kawai Tōru 
Published: April 2003

AbstractThe graft polymerization of styrene through use of γ‐ray irradiation was carried out in vapour phase onto polyethylene single crystals, bulk films of polyethylene and paraffine crystals. It was found that the grafting yield for a given dosage was much less for polyethylene single crystals than for bulk films. The similar difference was also found between the pure paraffine (n‐tetracosane) and mixed paraffines, and these results were interpreted in the light of crystallinity.In order to characterize the polystyrene branches grafted onto the crystals, a new method based on chain transfer reaction was proposed for obtaining number of the grafted points and the length of the branches and was applied to the graft polymerization onto the polyethylene single crystals.The results were compared with those obtained for the graft polymerization onto paraffine crystals. In the latter case, molecular weight of the graft polymer obtained after extracting paraffines from the whole material could be obtained by assuming the copolymer as polystyrene homopolymer. In both of the cases the polymer branch was very long and the sites of grafting were very few.The crystallinities of the samples measured by a X‐ray diffraction method before and after the grafting showed that the grafting did not practically affect the original crystals. The surfaces of the grafted crystals were also examined by an electron microscope and the result implied that the reaction took place mainly on the surfaces of the crystals.
Vinyl polymerization. 186. Polymerization of methyl methacrylate initiated by 9‐anthryldiazomethane
Authors: Nakaya Tadao , Ohashi Koichi , Imoto Minoru 
Published: April 2003

AbstractA study of the polymerization of methyl methacrylate initiated by 9‐anthryldiazomethane (ADM) has been made. The initial rate of polymerization, Rp, followed the equation:

This equation may be interpreted by the termination reaction of the growing radical with the primary radical. The rate of decomposition of ADM was measured in bulk or in benzene solution and the following rate equation was obtained:
Gelpermeationschromatographie. 1. Mitt. Die trennung oligomerer modellsubstanzen aus diphenylcarbonat und 4.4′‐dihydroxy‐diphenyl‐2.2′‐propan (bisphenol A)
Authors: Sotobayashi Von H. , Lie S. L. , Springer J. , Ueberreiter K. 
Published: April 2003

AbstractEs wurde versucht, Gemische oligomerer Modellsubstanzen aus Diphenylcarbonat und 4.4′‐Dihydroxy‐diphenyl‐2.2′‐propan (Bisphenol A) mit Hilfe der Gelpermeationschromatographie an Sephadexgelen (LH‐20) zu trennen. Die Messung der Verteilungskoeffizienten (Kd‐Werte) ergab, daß diese bei Substanzen mit phenolischen Endgruppen über den nach dem Molekulargewicht zu erwartenden Werten liegen, woür Adsorptionseffekte am Säulenmaterial verantwortlich gemacht werden. Bisphenol A besitzt einen besonders hohen Verteilungskoeffizienten. Seine Trennun von anderen Substanzen wurde theoretisch und experimentell untersucht. Daraus ergab sich eine neue Methode zur quantitativen Bestimmung, von Bisphenol A.
Some preliminary studies of the photo and photo‐oxidative degradation of polyoxymethylene
Authors: Grassie N. , Roche R. S. 
Published: April 2003

AbstractUnder both 2537 Å and 3650 Å irradiation i. vac. polyoxymethylenes evolve hydrogen and carbon monoxide in a molar ratio of 3.5–4.0. Irradiation in air produces well defined changes in the hydroxyl and carbonyl regions of the infrared spectrum. 2537 Å radiation is approximately 100 times more effective than 3650 Å radiation. Carbonyl absorption has been resolved into three components at 1750, 1785, and 1815 cm−1. Under 3650 Å radiation carbonyl absorption increases autocatalytically while under 2537 Å radiation and equilibrium concentration is quickly achieved. These observations are accounted for qualitatively in terms of current theories of organic oxidation processes.
Synthesis of optically active polymers by asymmetric catalysts. VIII. Asymmetric polyaddition of dimercaptan to dimethacrylate by optically active amine as catalyst
Authors: Inoue Shohei , Ohashi Shin'ichi , Tabata Akira , Tsuruta Teiji 
Published: April 2003

AbstractOptically active polymers could be obtained by the asymmetric polyaddition of tetramethylene dimercaptan to ethylene dimethacrylate using S‐isobutylethylenimine or its polymer as catalyst. Polymer catalysts showed an enhanced activity in the asymmetric polyaddition.
Conformational studies on oligo‐l‐iso‐butylethyleneurethans. Oligourethan. VII
Authors: Iiwata Kaoru , Iwakura Yoshio , Hayashi Katsumi 
Published: April 2003

AbstractThe conformations of oligo‐l‐iso‐butylethyleneurethans,

(L‐form, n = 1–7), in various solvents were studied by optical rotatory dispersion and infrared spectroscopy.All oligomers showed simple dispersion in solvents such as alcohols, cyclic ethers, m‐cresol, pyridine, chloroform, and tetrachloroethylene. On the other hand, the hexamer and heptamer showed anomalous dispersions in solvents such as benzene, toluene, and anisol, while lower homologues up to the pentamer showed simple dispersion in these solvents.The anomalous dispersions were interpreted as a helixThe term “helix” used in this paper for oligourethans means an ordered helical structure, it does not mean an α‐helix of peptides.
formation due to the intramolecular hydrogen bonding.Small angle X‐ray analysis demonstrated that the observed long spacings of the oigomers agreed well with the calculated chain lengths based on the fully extended models.
Anionic copolymerization of β‐lactones in correlation with the mode of fission. studies on the syntheses of aliphatic polyesters. XI
Authors: Yamashita Yuya , Tsuda Tetsuo , Ishida Hiroyasu , Uchikawa Akihiko , Kuriyama Yasuhisa 
Published: April 2003

AbstractThe copolymerization behavior of β‐propiolactone (PL) and α.α‐bischloromethyl β‐propiolactone (α‐BCPL) is correlated with the mode of fission. With sodium acetate as catalyst, the formation of β‐acetoxy propionic acid at the initiation reaction was observed and α‐BCPL was more than five times as reactive as PL in copolymerization. Thus propagation by carboxylate anion through alkyl‐oxygen fission was presumed in the case of pyridine and the acetate of Na, Li, and Mg as catalyst. On the other hand, the formation of ethyl β‐hydroxy propionate and the decreased reactivity of α‐BCPL in copolymerization was observed with magnesium and aluminum ethoxide as catalyst. In the case of the ethoxide of Na, Li, and Al, and Et2Mg or Et3Al as catalyst, propagation by alkoxide anions through acyl‐oxygen fission of the coordinated lactones was presumed.
Über die synthese polymerer indophenine und deren elektrische eigenschaften
Authors: Kossmehl Von G. , Manecke G. 
Published: April 2003

AbstractDurch Kondensation von Bis‐{dioxopyrrolino[2′.3′: 1.2; 2″.3″: 5.4]}benzol mit Thiophen sowie durch Reaktion eines Poly[6‐vinylisatin]‐harzes mit Isatin und Thiophen wurden zwei verschiedenartig aufgebaute, Indophenineinheiten enthaltende Polymere synthetisiert, die polymere Küpenfarbstoffe sind.Das polymere Indophenin I mit einem System konjugierter Doppelbindungen und einem koplanaren Molekülaufbau besitzt bei 25°C und einem Druck von 1500 kp · cm−2 eine spezifische elektrische Leitfähigkeit von σ = 1,1 · 10−4 Ω−1 · cm−1. Die Spinkonzentration beträgt 1,9 1020 spins g−1. Außerdem wurden zum Vergleich die elektrischen Eigenschaften und Spinkonzentrationen von einigen Redoxharzen, die indigoide Farbstoffe bzw. chinoide Strukturen aufweisen, untersucht.
Radiation polymerization of perhydrotriphenylene‐included butadiene
Authors: Löffelholz Marco , Farina Mario , Rossi Umberto 
Published: April 2003

AbstractThe planar isomer of perhydrotriphenylene (PHTP) is a new host molecule for the inclusion polymerization of butadiene. By γ‐irradiation of the PHTP‐monomer adduct an inclusion compound between PHTP and the polymer is obtained, as revealed by its melting point. The recovered polymer has a highly regular trans‐1.4‐structure. The effect of different variables (dose, dose‐rate, PHTP/monomer ratio) has also been studied.
Vinyl polymerization. 202. Polymerization of styrene initiated with the imidazole/carbon tetrachloride system: A kinetic study
Authors: Imoto Minoru , Takemoto Kiichi , Azuma Heiichi 
Published: April 2003

AbstractThe polymerization of styrene initiated with the imidazole/carbon tetrachloride system was studied kinetically in a benzene/acetone solution at 85°C. It was found that the rate of polymerization could be expressed by the following equation:

From the results the initiation mechanism was discussed.
Polymerization of cyclic acetals. Cationic polymerization of 2‐vinyl‐4.5‐dimethyl‐1.3‐dioxolane
Authors: Jedliński Z. , Łukaszczyk J. 
Published: April 2003

AbstractThe cationic polymerization of 2‐vinyl‐4.5‐dimethyl‐1.3‐dioxolane (VDMD) with BF3·Et2O, SnCl4, TiCl4, and various cocatalysts was investigated, and probable reaction mechanisms were proposed. Linear oily products of low molecular weight have been obtained. In contrast, the unsubstituted 2‐vinyl‐1.3‐dioxolane forms cross‐linked polymers. Methylene substituents in positions 4 and 5 in acetal rings make it less reactive. Crosslinked polymers from VDMD were also obtained, when epichlorohydrine was used as cocatalyst. These cross‐linked products contain halogen. This shows the possibility of copolymerization of epichlorohydrine and VDMD beside a cocatalytic effect.
Versuche zur herstellung eines makroporösen polymethacrylat‐gels
Authors: Determann Helmut , Kriewen Manfred , Wieland Theodor 
Published: April 2003

AbstractDurch Copolymerisation von Methacrylsäuremethylester und Äthylenglykoldimeth acrylsäureester in Gegenwart verschiedener, nachträlich entfernbarer Füllstoffe (Polystyrol, Glukose, Calciumcarbonat and Natriumcarbonat) wurden Gele erhalten, die nach Zerkleinerung auf ihr chromatographisches Trennvermögen für Makromoleküle in Tetrahydrofuran geprüft warden. Die Gele zeigen im Bereich hoher Molekulargewichte eine gewisse Trenniwirkung.
Catalytic effects of poly(acrylhydroxamic acid)‐copper chelates on decomposition reaction of hydrogen peroxide
Authors: Hatano Masahiro , Nozawa Tsunenori , Yamamoto Takakazu , Kmbara Shu 
Published: April 2003

AbstractDecomposition reaction of hydrogen peroxide was effected under various conditions by using poly(acrylhydroxamic acid)‐copper chelates as catalysts. The catalytic effect of these chelates is discussed on the basis of kinetic data concerning, with chelate formation from the polymeric ligands (L). The initial rate of the decomposition reaction which depended upon the initial concentration of hydrogen peroxide, increased with the ratio of total concentration of cupric ion to total concentration of the ligand group (TCu/THL). The relation between initial rate and the initial concentration of hydrogen peroxide varied in accordance with the rate expression of MICHAELIS‐MENTEN type. These experimental results are discussed on the basis of values of chelate formation constants obtained in the preceding paper. Thus, the chemical species which contribute to the catalytic activity were assumed to be CuL+, e.i., the chemical species derived from a cupric ion and one hydroxamic group. So, an addition of this ligand in excess with respect to formation of CuL+ caused competitive inhibition for the decomposition reaction of hydrogen peroxide.
Über Derivate des Poly‐α‐chloracroleins. II. Dehydrochlorierung von Poly(α‐chloracroleindimethylacetal‐co‐vinylchlorid) und Poly‐α‐chloracroleindiacetat mit Basen
Authors: Lengweiler Von Willi 
Published: April 2003

AbstractDie Dehydrochlorierung des Poly(vinylchlorid‐co‐α‐chloracroleindimthylacetals) mit Natriumamid in Ammoniak oder Tetrahydrofuran führt schon bei einem Chlorgehalt unterhalb 36,5% zu unlöslichen Produkten. Mit Kalium‐tert‐butylat waren die Dehydrochlorierungsprodukte dagegen noch his zu einem Gehalt von ca. 10% Chlor löslich. Die Delhydroclorierungsgeschwindigkeit ist beim Kalium‐tert‐butylat praktisch unabhüngig von der Copolymerzusammensetzung. Bei hohen Basenkonzentrationen und kleinen Dehydrochlorierungsgraden hängt die Geschwindigkeit nur von der Chlorkonzentration ab, bei hohen Dehydrochlorierungsgraden dagegen nur noch von der Basenkonzentration. Für diese Grenzfälle wurden die ungewöhnlichen Exponenten von 3,3 Für die Chlorkonzentration bzw. 4,3 Für die Basenkonzentration gefunden. Das Heptaen weist unterhalb eines Chlorgehaltes von etwa 34% immer das höchste Absorptionsmaximum auf, wenn von einem Copolymeren mit 74 Mol‐% Vinylchlorid ausgegangen wird. Die Reaktionstemperatur hat keinen Einfluß auf die Sequenzverteilung der konjugierten Doppelbindungen. Dien‐ und Trien‐Sequenzen sind bei allen Reaktionszeiten am häufigsten vorhanden.
Anionic copolymerization of ω‐lactams with ω‐lactones
Authors: Komoto Hiroshi 
Published: April 2003

AbstractCopolymerizations of ε‐caprolactam, α‐pyrrolidone or α‐piperidone with ε‐caprolactone or δ‐valerolactone have been carried out in the presence of alkali metal. It has been shown that in copolymerizations of ε‐caprolactam or α‐pyrrolidone with ε‐caprolactone and α‐pyrrolidone with δ‐valerolactone conversions of above 70 % and reduced viscosities of above 0.5 in m‐cresol at 35°C for all compositions were obtained. In the case of copolymerization of ε‐caprolactam with δ‐valerolactone at 180°C a conversion of 25 % and a reduced viscosity of 0.5 were obtained, but the polymer was polycaproamide, while at 90°C the conversion was 50 % but the polymer was polyvalerolactone. In copolymerizations of α‐piperidone with ε‐caprolactone or δ‐valerolactone the copolymer contained only polyester.A mechanism is proposed for the copolymerization of ω‐lactams with ω‐lactones with alkali metal, which involves chain propagation by the stepwise addition of the lactam ring at an end of the chain molecule and by the stepwise addition of the lactone ring at the other end of the chain molecule, resulting to a certain extent in the formation of polyester and polyamide segments.This mechanism is supported by experimental results obtained through the reaction in the presence of alkali metal salts of ω‐lactam, data on infrared analyses and elementary analyses, and by experimental results obtained through measurements of physical properties of these copolymers.
The butyllithium initiated bulk anionic polymerization of α‐methylstyrene
Authors: Wyman D. P. , Song I. H. 
Published: April 2003

AbstractButyllithium (BuLi) initiates α‐methylstyrene polymerization in bulk at room temperature. Both initiation and propagation reactions are very slow and propagation/depropagation occurs along with other side reactions, e.g., transfer. At slightly elevated temperatures (40–50°C) irreversible termination takes place. Molecular weights change inversely but not linearly with changes in [BuLi] and distributions are broad (M̄w/M̄n = 1.55 to 2.2) as would be expected from equilibria considerations. These results are generally different than those reported with sodium initiated reactions.
Studies on organometallic compounds as polymerization catalysts. II. Diethylzinc/water system for epoxide polymerization
Authors: Ishimori Michihiro , Nakasugi Osami , Takeda Nobuyuki , Tsuruta Teiji 
Published: April 2003

AbstractDiethylzinc/water system was studied using infrared spectroscopy, X‐ray diffraction, and vapor phase chromatography. The main reactions of diethylzinc with water are considered to be as follows:

Relative LEWIS acidity for ether is found to be in the order:

Initiators for the polymerization of propylene oxide by diethylzinc/water system are found to be Et(ZnO)nZnEt, Et(ZnO)nH, or HO(ZnO)nH, which have disordered wurtzite structures concerning zinc‐oxygen bond. On the hydrolysis of the polymerization system, 2‐methyl‐l‐butanol, 2‐pentanol, and propylene glycol are found as initial products. The main reaction of the polymerization of propylene oxide catalyzed by diethylzinc/water system was discussed in terms of the coordinate ionic mechanism.
Copolymere von Vinylhalogeniden mit Olefinen. 1. Qualitative IR‐spektroskopische Untersuchungen an Vinylchlorid‐Propen‐Copolymeren
Authors: Pohl Von H. U. , Denaxas J. , Hummel D. O. 
Published: April 2003

AbstractZwei Reihen von Vinylchlorid‐Propen‐Copolymeren, strahlenchemisch polymerisiert bei −63 und +23°C, wurden im Bereich von 5000 bis 400 cm−1 IR‐spektroskopisch untersucht. Die Zuordnung der Banden zu den einzelnen Strukturen basiert auf ihrer Intensitätsänderung mit zunehmender Polymerisations‐ und Meßtemperatur sowie steigendem Propengehalt der Proben. Die Spektren ermöglichen Aussagen über die Struktur der Copolymerenketten.
Copolymere von Vinylhalogeniden mit Olefinen. 2. Quantitative IR‐spektroskopische Untersuchungen an Vinylchlorid. Propen‐Copolymeren
Authors: Pohl Von H. U. , Hummel D. O. 
Published: April 2003

AbstractDie überlagerten ν(CCl)‐Schwingungen im Bereich von 600 bis 700 cm−1 sowie die δ(CH3)‐ und δ(CH2)‐Schwingungen zwischen 1370 und 1470 cm−1 wurden in Einzelbanden aufgetrennt. Die Halbwertsbreiten und relativen integralen Extinktionen dieser Banden wurden in Abhängigkeit von der Zusammensetzung an zwei Copolymerenreihen der Polymerisationstemperatur +23°C und −63°C bestimmt. Verschiedene Möglichkeiten einer IR‐spektroskopischen Ermittlung der Zusammensetzung von Vinylchlorid‐Propen‐Copolymeren wurden untersucht.
Synthesis and conformational studies of oligo‐1‐iso‐propylethyleneurethans. Oligourethans. VIII.
Authors: Iwata Kaoru , Iwakura Yoshio , Hayashi Katsumi 
Published: April 2003

AbstractOligo‐1‐iso‐propylethyleneurethans with one to four repeating units,

were synthesized by a stepwise method. Their conformational aspects in solution were investigated by optical rotatory dispersion, infrared spectroscopy, and nuclear magnetic resonance.It was concluded that the monomer through trimer exist as random coils in all solvents tried while the tetramer forms a helical structure in such solvents as ethanol, benzene, toluene, and xylene. Dioxane and chloroform were random‐coil solvents for the tetramer. The helical structure was destroyed by the addition of a random‐coil solvent or by elevating temperature.The intramolecular hydrogen bonding between NH and CO was demonstrated to participate in the helixThe term „helix”︁ used in this paper for oligourethans means an ordered helical structure and does not necessarily mean the α‐helix of peptides.
formation.
Ternary polymerization catalyst consisting of group ii metal halide, triethylaluminum and carbon tetrachloride
Authors: Saito Kazuo , Saegusa Takeo 
Published: April 2003

AbstractThe present paper describes the ternary catalyst system consisting of Group II metal halides, AlEt3, and CCl4, which initiatesatroom temperature the polymerizations of ethylene (60 atmospheres), styrene, vinyl acetate, methyl methacrylate, acrylonitrile, and isobutyl vinyl ether. As the component of Group II metal halide, ZnCl2, ZnI2, CdCl2, MgCl2, and BeCl2 were effective. This catalyst system induced the cationic polymerization of vinyl ether. On the other hand, the copolymer composition curve of the styrene‐methacrylate copolymerization with this catalyst system was close to that of free radical copolymerization. In addition, this catalyst system has also been characterized by the 1:1 alternating copolymerization of ethylene with vinyl acetate at room temperature.
Comparative studies of the solution properties of vinyl aromatic polymers
Authors: Utracki Lechoslaw A. , Simha Robert 
Published: April 2003

AbstractViscosity and NMR studies of poly‐1‐vinylnaphthalene, (PIVN), poly‐2‐vinylnaphthalene, (P2VN), and poly‐vinylbiphenyl, (PVB) solutions were carried out over a range of temperatures and molecular weights. For these polymers as well as polystyrene the viscosities at finite concentrations indicate two transition regions at about 20 and 50°C. At infinite dilution no transitions were observable except for P2VN, where a transition region around 45°C was noted. From the temperature and molecular weight dependence of [η], the conformational parameter σ = (〈r〉/〈r〉)1/2, interaction parameter B and their temperature dependence are obtained. For P1VN and P2VN, dσ/dT < 0, whereas the opposite holds for PVB. At 30°C, σ is a linear function of the volume of the pendant group. The transition observed by viscosity and NMR is not reflected in B. For P2VN and PVB dB/dT < 0. For P1VN which was found to be partially crystalline, dB/dT > 0. From the NMR studies of P2VN solutions the activation energy of the main transition at 50° is calculated as E = 23 ± 4 kcal/mole for 100% polymer, indicating strong hindrance of motions. The transition has been ascribed to motions of the backbone chain.
The bulk and suspension polymerization of vinyl chloride
Authors: Crosato‐Arnaldi A. , Gasparini P. , Talamini G. 
Published: April 2003

AbstractThe bulk and suspension polymerization of vinyl chloride are studied.The comparison between the two processes demonstrates that they are kinetically equivalent.It is found that an equation recently suggested to describe the bulk polymerization of vinyl chloride agrees quite well with the experimental data.
Ionic polymerization under an electric field. XI. Field effect and catalyst strength
Authors: Ise Norio , Hayashi Yuzuru , Chen Shou‐Xyng , Sakurada Ichiro 
Published: April 2003

AbstractThe influence of an electric field on homopolymerizations and copolymerizations of styrene catalyzed by stannic chloride/trichloroacetic acid (SnCl4/TCA) or titanium tetrachloride‐trichloroacetic acid (TiCl4/TCA) in binary mixtures of toluene and 1.2‐dichloroethane was investigated. The field enhancement in the homopolymerization increased with increasing dielectric constant of solvent, and, passing through a maximum value, decreased with further increase in the dielectric constant. The value of the dielectric constant, at which the field effect showed a maximum value, increased with catalyst in the order: TiCl4/TCA < SnCl4/TCA < boron trifluoride etherate (BF3OEt2). This order was the same as that for the field effect on the rate of homopolymerization in pure 1.2‐dichloroethane. The reactivity of styrene in the copolymerization of styrene and indene in pure 1.2‐dichloroethane increased in the order: BF3OEt2 < SnCl4/TCA < TiCl4/TCA. The electric field increased the reactivity of styrene in the copolymerization in the order: TiCl4/TCA < SnCl4/TCA < BF3OEt2. It was concluded from the observed sequence, on the basis of the mechanism proposed previously, that the catalyst strength for the Styrene polymerization increases in the order: BF3OEt2 < SnCl4/TCA < TiCl4/TCA. This sequence was in agreement with that reported earlier.