bluuebunny/crossref_metadata_2025 huggingface dataset:
Étude du pouvior émulsifiant des copolymères séquencés polystyrène/chlorure de polyvinyl‐2 pyridinium et polyisoprène/chlorure de polyvinyl‐2 pyridinium
Authors: Marie Pascal , Herrenschmidt Y‐Lê , Gallot Yves
Published: April 2003

On a étudié de manière approfondie l'effet émulsifiant des copolymères séquencés polystyrène/chlorure de polyvinyl‐2 pyridinium et polyisoprène/chlorure de polyvinyl‐2‐pyridinium. On a ainsi montré, qu'en présence de deux solvants non miscibles et sélectifs de chaque séquence, ces copolymères donnent des émulsions stables qui sont de type huile dans eau ou eau dans huile selon les caractéristiques moléculaires des copolymères considérés. Plus précisément, les copolymères à forte teneur en chlorure de vinyl‐2 pyridinium conduisent uniquement à des émulsions huile dans eau, tandis que les copolymères riches en styrène (ou en isoprène) donnent préférentiellement des émulsions eau dans huile.
Enzymatic cleavage of side chains of synthetic water‐soluble polymers
Authors: Drobník J. , Kopeček J. , Labský J. , Rejmanová P. , Exner J. , Saudek V. , Kálal J.
Published: April 2003

Water‐soluble copolymers based on poly[N‐(2‐hydroxypropyl)methacrylamide] and bearing in their side chains a chromogenic substrate for chymotrypsin were prepared by direct copolymerization or polymeranalogous reaction. The substrate was L‐phenylalanine‐4′‐nitroanilide linked by its amino group to the terminal carboxylic group of the side chain. The cleavage of the substrate thus bonded, was expressed by means of the Michaelis constant, the maximum velocity, and the percentage of substrate unit accesible to the enzyme. The effect of length and chemical structure of the side chain was investigated in the first place. It was found that the chain must be longer than 6 atoms; longer chains are generally more favourable for this cleavage. The ε‐aminocaproyl group provides a chain that is most favourable for the cleavage, whereas chains with several glycyl units, though longer, are less favourable. Polymers with higher content of the substrate units undergo cleavage more readily.
Synthèse par voie radicalaire de polymères à extrémités hydroxylées, 3. Synthèse de poly(acétate de vinyle)
Authors: Pinazzi Christian , Lenain Jean‐Claude , Brosse Jean‐Claude , Legeay Gilbert
Published: April 2003

Sous l'action de la chaleur, le peroxyde d'hydrogène est scindé en radicaux hydroxyle pouvant agir comme agents d'amoràe d'un processus de polymérisation. On peut ainsi obtenir des polymères hydroxylés de petites masses moléculaires. L'adjonction d'un alcool au milieu réctionnel modifie les conditions de la polymérisation et permet de moduler les taux de conversion et les masses moléculaires moyennes en nombre. Les résultats sont différents selon que le polymère est soluble ou non dans l'alcool. La polymérisation de l'acétate de vinyle selon ce procédé, dans le méthanol solvant du polymère, fait l'objet du présent travail. La nature des polymères obtenus est déterminée: mode de distribution des masses moléculaires, microstructure, taux de groupements hydroxyle par macromolécule; l'influence de divers paramètres est éaglement étudiée: durée, température, proportions d'eau oxygénée et de solvant.
Synthèse par voie radicalaire de polymères à extrémités hydroxylées 4. Polymérisation et copolymérisation de butènes
Authors: Pinazzi Christian , Legeay Gilbert , Brosse Jean‐Claude
Published: April 2003

L'homopolymérisation dans le méthanol des butène‐1, butène‐2 et isobutène amorcée par l'eau oxygénée conduit à la formation, avec de faibles taux de conversion, de polymères de faibles ou de très faibles masses moléculaires comportant des fonctions hydroxyles. La copolymérisation de ces éthyléniques avec un monomère diènique, tel que le butadiène, s'effectue facilement. Les constantes de réctivité ont été déterminées. Elles sont liées aux structures des monomères: le butène‐2 polymérise et copolymérise mieux que l'isobutène mais moins bien que le butène‐1.
Studies on aqueous polymerization of acrylamide, 2. Potassium persulfate/2‐mercaptoethanol redox system
Authors: Husain M. Mukhtar , Misra Sada Nand , Gupta Archana
Published: April 2003

The polymerization of acrylamide in aqueous media initiated by the potassium persulfate/2‐mercaptoethanol redox pair was studied at 30°C under nitrogen atmosphere. The initial rate of polymerization was found to be proportional to nearly the 1,5th power of the potassium persulfate concentration within the range of 0,6 to 2,0 mmol l−1 and to the first power of acrylamide concentration in the range of 0,1 to 0,14 mol l−1. The rate was also found to be proportional to the first power of the 2‐mercaptoethanol concentration within the range 4,0 to 8,0 mmol l−1. The overall activation energy was found to be 134 kJ mol−1.

Further the effect of salts (NaCl, KCl, NH4Cl, Na2C2O4, K2C2O4·H2O, (NH4)2C2O4,MnSO4·4H2O, and NaF) and aliphatic alcohols (methanol, ethanol, and propanol) was tested.
Reaktion an Ziegler‐Natta‐Katalysatoren, 12. Anwendung der Olefin‐Metathese zum Nachweis einer radikalischen Aralkylierung von 1,4‐Polybutadien
Authors: Hummel Klaus , Demel Hans , Wewerka Dieter
Published: April 2003

1,4‐Polybutadien wurde mit Alkylbenzolen (Toluol, Äthylbenzol, o‐, m‐ und p‐Xylol, Mesitylen) und Dicumylperoxid in einer radikalischen Reaktion partiell aralkyliert. Die erhaltenen Polymeren wurden IR‐spektroskopisch untersucht und durch Metathese mit 4‐Octen unter Verwendung eines WCl6/Sn(CH3)4‐Katalysators abgebaut. Die niedermolekularen Abbauprodukte mit Aralkylsubstituenten wurden gaschromatographisch getrennt und massenspektrometrisch identifiziert.
Über die homopolymerisation des N‐(pentachlorphenyl)maleinimids und des N‐(2,4,6‐tribromphenyl)maleinimids
Authors: Bouchal Karel , Ryska Miroslav , Hrabák František
Published: April 2003

New monomers with a high content of halogens, N‐(pentachlorophenyl) maleimide (1) and N‐(2,4,6‐tribromophenyl) maleimide (2) were prepared. The products of their radical polymerization consist of oligomers. Of these, products with the degree of oligomerization, n, ranging from 1–4 and from 1 to 3 were separated on a gel chromatograph for 1 and 2, respectively. Their structures were determined from the mass spectra. The elution volumes Vn of the individual oligomers were found to be a linear function of log Mn. The radical polymerization mechanism of 1 and 2 is discussed on the basis of the character of oligomers.
The copolymerization and 1,4‐cycloaddition reactions of polar vinyl monomers with butadiene in the presence of Lewis acids as catalysts
Authors: Kuran Witold , Pasynkiewicz Stanisław , Florjańczyk Zbigniew , Łyszkowska Danuta
Published: April 2003

The copolymerizations of acrylonitrile, methacrylonitrile, methyl acrylate, methyl methacrylate, methyl vinyl ketone, acroleine, and acrylic acid with butadiene were carried out in the presence of the Lewis acids ZnCl2, BF3, CH3AlCl2, C2H5AlCl2, AlCl3, SnCl4, and TiCl4 and also in the absence of catalyst. Relative reactivity orders of the above polar vinyl monomers in the copolymerization and 1,4‐cycloaddition reactions with butadiene and also the catalytic activity orders of Lewis acids in these reactions were determined. The composition of the polymers formed and the structure of their butadiene units were also determined. The mechanism of the copolymerization and 1,4‐cycloaddition of the polar vinyl monomers with butadiene in the presence of Lewis acids is discussed.
Infrarotspektren der koordinationsverbindungen von poly(vinylpyridin)en mit den chloriden von Rh, Ru und Pd
Authors: Roda Jan
Published: April 2003

The paper contains the IR‐spectra of the coordination compounds of the poly(2‐,3‐, and 4‐vinylpyridine)s with the chlorides of Ru, Pd, and Rh. The shifts of the fundamental vibrations of the pyridine ring are discussed, and the spectra are analysed. In comparison with low molecular weight analogues, the spectra are simpler, and the vibration bands are wider, which is due to the polymeric character of the ligands.
Metal complexes of alkyl substituted poly(vinylpyridine 1‐oxide)s and of poly (dimethylaminostyrene N‐oxide)s
Authors: Alshaikh‐Kadir Khalid , Holt Paul F.
Published: April 2003

Three alkyl derivatives (3, 4, and 5) of poly[1‐(N‐oxo‐pyridyl)ethylene]s (poly(vinylpyridine 1‐oxide)s) give complexes with some or all chlorides of copper (II), zinc, mercury(II), iron(III), and cobalt(II), in which all the N‐oxide groups are coordinated with metal, the mole ratio NO/metal being 2:1. The three poly[(N‐oxo‐dimethylamino)phenylethylene]s (poly(dimethylaminostyrene N‐oxide)s) (6, 7, and 8) give complexes with copper(II), mercury(II), and iron(III) chlorides but, even when an excess of metal chloride is available, some N‐oxide groups do not coordinate with metal as shown by IR absorption data. The degree of coordination is 0,5 for complexes of 6, but it is 0,4 for the complexes of 7 and 0,33 for the complexes of 8.
Über die boronierung von polystyrol
Authors: Hartmann Manfred , Carlsohn Hartmut
Published: April 2003

Boronic acid groups can be introduced in crosslinked and linear polystyrene by metalation with the complex butyllithium/N,N,N′,N′‐tetramethylethylenediamine and subsequent treatment with boric acid esters. Investigations of the photochemical boronation of polystyrene by boron tribromid show that the reaction is accompanied by strong chain degradation, whereas the former method leads to an increase in molecular weight.
Polar effect in free volume theory for polymer solution thermodynamics
Authors: Sugamiya Ken
Published: April 2003

Polar effects on the thermodynamic properties of polymer solutions are treated within the framework of the free volume theory. The Sutherland potential and the dipole‐dipole interaction are assumed to represent intermolecular interaction in a polar system, with an approximation concerning the radial distribution function. Application of the treatment to some polar systems shows that the theoretical %‐parameters are smaller than the observed ones and than the calculated ones without regard to the polarity. The excess volume ratios are, however, nearer to the observed ones compared with those evaluated without the account of the polarity. Therefore, the present results are fairly good for strong polar solutions.
Thermostimulated creep and depolarization thermocurrent in low density polyethylene
Authors: Chatain Daniel , Lacabanne Colette , Monpagens Jean‐Claude
Published: April 2003

A new method for the study of orientational movements in polymeric solids is proposed: in a mechanical step‐function experiment, we thermally stimulate the response at a constant stress. The great advantage of the thermostimulated creep (TSC) technique is to allow the experimental resolving of the mechanical retardation time spectrum. In low density polyethylene, the existence of a discrete spectrum of mechanical retardation times is demonstrated; it has the same fine structure than the spectrum of dielectric relaxation times deduced from the study of depolarization thermocurrent (DTC) on the same sample.
Asymmetric oxidation of sulfides with N‐chloro‐nylon‐6.6 in the presence of optically active alcohols
Authors: Sato Yoshiyasu , Kunieda Norio , Kinoshita Masayoshi
Published: April 2003

Treatment of sulfides with N‐chloro‐nylon‐6.6 in the presence of water or alcohols affords the corresponding sulfoxides in good yields. 18O is incorporated in the corresponding sulfoxides by oxidation using H2 18O as oxygen source. A remarkable retardation of the oxidation is observed in the case of using alcohols with a bulky group. In the presence of optically active alcohols, the oxidation of sulfides results in the formation of optically active sulfoxides. The stereochemical route for the asymmetric oxidation is discussed.
Optically active vinyl polymers containing fluorescent groups, 2. Synthesis of optically active vinyl carbazole derivatives
Authors: Chiellini Emo , Solaro Roberto , Ledwith Anthony
Published: April 2003

Synthesis and characterization of (S)‐3‐sec‐butyl‐9‐vinylcarbazole (7), (S)‐9‐(2‐methylbutyl)‐2‐vinylcarbazole (14), and (S)‐9‐(2‐methylbutyl)‐3‐vinylcarbazole (18) are described in detail.
13C NMR analysis of chemical inversion in polypropylene
Authors: Asakura Tetsuo , Ando Isao , Nishioka Atsuo , Doi Yoshiharu , Keii Tominaga
Published: April 2003

Several new peaks observed in the 13C NMR spectra of polypropylene prepared with a VCl4/Al(C2H5)2Cl catalyst were assigned to the chemical inversion in the chain such as an isolated head‐to‐head or tail‐to‐tail unit.
Synthesis of oligomers containing several hydroxyimino groups
Authors: Yukimasa Hidefumi , Sawai Hiroaki , Obata Naruyoshi , Takizawa Takeo
Published: April 2003

Octane‐3,6‐dione (1a) and undecane‐3,6,9‐trione (1b) were prepared by co‐oligomerization of ethylene and carbon monoxide in the presence of rhodium trioxide catalyst. C‐Nitrosation of active methylene groups of 1a and 1b with butyl nitrite or nitrosyl chloride gave products 3, 4, 6, and 7 and 10–14 containing hydroxyimino groups or isoxazole rings. The oximes 16–20 were obtained by oximation of carbonyl groups of 1a, 3, 4, 6, and 7 with hydroxylamine hydrochloride.
Reactivity ratios of ionizing monomers in aqueous solution. Copolymerization of acrylic and methacrylic acids with acrylamide
Authors: Ponratnam Surendra , Kapur Sham Lal
Published: April 2003

The copolymerization behaviour of the systems (a) acrylic acid (AA)‐acrylamide (AM) and (b) methacrylic acid (MA)‐acrylamide was studied in aqueous solution at 30°C as a function of pH. The copolymerization was carried out to high conversion (>10%) and the monomer reactivity ratios r1 for (AA or MA) and r2 (for AM) were computed using the Mayo‐Lewis integrated equation. For the system (a), r1 reached its maximum value of 0,92 at pH 2, and its minimum of 0,33 at pH 6, thereafter increasing again. No systematic variation was found for r2. In system (b), r1 decreased sharply from a maximum of 2,8 at pH 4 to 0,19 at pH 6, then increasing to 0,39 as the pH was raised to 10. The r2 value showed a gradual increase from 0,2 at pH 4 to 0,57 at pH 9. Addition of NaCl (conc.: 1 mol/l) partially restored the value of r1 for both AA and MA to those at low pH. The variation of r1 of AA and MA nearly parallelled the homopolymerization rates of the respective monomers, with respect to pH. These variations were traced to the electrostatic repulsive interactions between the reactive species—ionized monomer and ionized polymeric radical—and hydrophobic interactions. Certain discrepancies in the trends of r1 and r2 were also noted.
Determination of crystallinity of polyethylene powder by inverse chromatography
Authors: Hudec Pavel
Published: April 2003

The problem of crystallinity determination of polyethylene powder was studied utilizing the method of inverse chromatography. The data obtained were found to be dependent on the polymer particle diameter. A relation was proposed describing this observation, and using this realtion the crystallinity of a polyethylene sample was calculated.
Greffage d'acides aminés possédant une troisième fonction sur un polymère, 3 Fixation de lysine aux extrémités d'un polymère α,ω‐difonctionnel. – Modèle de réaction
Authors: Guéniffey Henri , Garnier Raymonde , Pinazzi Christian
Published: April 2003

Lysine, as cupric complex, was fixed by its ε‐NH2 end group onto pentamethylene or 3‐oxapentamethylene dichloroformates, and to sebacoyl dichloride. Copper elimination yields dicarbamates and diamides which can be used as prepolymers or as crosslinking agents.
Copolymerization of carbon dioxide and some oxiranes by organoaluminium catalysts
Authors: Koinuma Hideomi , Hirai Hidefumi
Published: April 2003

Carbon dioxide was copolymerized with methyloxirane and 7‐oxabicyclo[4.1.0]heptane using triethylaluminium as a catalyst component. Factors to control the copolymer composition were sought on the basis of an assumed copolymerization mechanism. Compared to nonpolar solvents, ethereal solvents were found to increase the carbon dioxide content in the copolymer obtained by the triethylaluminium/water system, giving a fraction with almost alternating sequence. The addition of a Lewis base, especially treiphenylphosphine, to triethylaluminium was also useful to get copolymers of high carbon dioxide content. The coincidence of these results with the expectation from the assumed copolymerization scheme clearly indicates that the copolymerization proceeds through a coordinated anionic mechanism.
Polymere ester von Säuren des phosphors, 5. Ringöffnende polymerisation des 2‐phenoxy‐1,3,2‐dioxaphospholan durch Michaelis‐Arbuzov‐reaktion
Authors: Vogt Walter , Ahmad Nasim U.
Published: April 2003

2‐Phenoxy‐1,3,2‐dioxaphospholane (14) was polymerized by benzyl halogenides at temperatures between 120 and 200°C. It was found that the main chain consists predominantly of unexpected ethylene 1,2‐ethanediphosphonate units 7; only about 10% of the monomer was incorporated as the expected 2‐hydroxyethanephosphonate structure. An insertion mechanism, proposed by Harwood and Patel for the analogous polymerization of 2‐phenyl‐1,3,2‐dioxaphospholane, does not agree with our experimental results. A hypothesis is developed involving a two step addition process, which exclusively occurs at the chain end. Alternating, one monomer molecule is added by a normal Michaelis‐Arbuzov‐reaction, and then a second molecule is added followed by an intermediate 1,2‐shift of the endstanding halogen cryptoanion. With benzyl bromide as initiator, the growing end shows alternating the sequences CPOCCBr (2‐bromoethyl ester) and COPCCBr (2‐bromoethanephosphonate).
Die struktur kollagenähnlicher homo‐ und heteropolytripeptide, 3. Die synthese von iysinhaltigen polytri‐ und ‐hexa‐peptiden
Authors: Khodadadeh Keyumarss , Heppenheimer Kurt , Heidemann Eckhart R.
Published: April 2003

The syntheses and polycondensations of Nε‐Z‐L‐Lys‐Gly‐L‐Pro (5), L‐Pro‐Nε‐Z‐L‐Lys‐Gly (11), Gly‐L‐Pro‐Nε‐Z‐L‐Lys (17), Nε‐Z‐L‐Lys‐Gly‐L‐Ala (23), Nε‐Z‐L‐Lys‐Gly‐L‐Pro‐L‐Ala‐Gly‐L‐Pro (35), Gly‐L‐Glu(OBut)‐Nε‐Z‐L‐Lys‐Gly‐L‐Pro‐L‐Pro (46), and Gly‐L‐Pro‐Nε‐Z‐L‐Lys‐Gly‐L‐Pro‐L‐Pro (54), are described. The polymers were separated by gelchromatography into three fractions of different molecular weights. The polymers of 5 and 35 cannot be redissolved after lyophilization.
Influence of the nature of the solvent on the lamellar crystalline structure of block copolymers with an amorphous block and a crystallizable poly(ethylene oxide) block
Authors: Gervais Monique , Gallot Bernard
Published: April 2003

Block copolymers of styrene and ethylene oxide, (SEO), and of butadiene and ethylene oxide, (BEO), in the presence of a preferential solvent of the amorphous block exhibit always a lamellar structure (LC) with crystallized and folded poly(ethylene oxide) chains at temperatures below about 50°C.

To precise the influence of the nature of the solvent on the refolding of the poly(ethylene oxide) chains (PEO), we have studied by X‐ray diffraction and differential scanning calorimetry the LC structure of the copolymers BEO and SEO in the presence of different solvents for the amorphous block. The copolymers SEO were studied in the presence of xylene, toluene and diethyl phthalate. Diethyl phthalate being a bad solvent for polybutadiene, the copolymers BEO were studied only in the solvents xylene and toluene.

The influence of the nature of the solvent on the extent of the domain where the LC structure exists, on the refolding, and on the crystallinity of the poly(ethylene oxide) blocks is demonstrated.
Zur entschmierung der röntgenkleinwinkelstreukurven von hochpolymeren
Authors: Schollmeyer Eckhard , Tschang Chung‐Ji , Hirt Peter , Herlinger Heinz
Published: April 2003

A method for slit‐hight corrections is described, in which the experimental X‐ray small angle scattering curve is represented by a cubic spline function. This method is applied on the theoretical scattering curve of spherical particles with homogenious electron‐density and on scattering curves of poly(hexamethylene adipate).
On the kinetics of the polymerization of some ammonium methacrylates with different alkyl chain lengths in aqueous solution
Authors: Ringsdorf Helmut , Thunig Dieter
Published: April 2003

Methacryloyloxyalkyltrimethylammonium chlorides (1a–c) with different alkyl chain lengths were synthesized and polymerized radically with 4,4′‐azobis(4‐cyanovalerianic acid) and K2S2O8 as initiators. With K2S2O8 as initiator, reaction orders of 0,5 and 1 with respect to initiator and monomer, were found. For the ionic monomers with longer alkyl chains the ratio of rate constants kp(2fkd/kt)0,5 was determined over a wide concentration range. It was found that with decreasing monomer concentration the ratio of rate constants increases, which is caused by a diminished termination rate because of an increased electrostatic repulsion of the ionic polymer radicals in dilute solution (increase of dissociation). Methacryloyloxyethyltrimethylammonium chloride (1a) doesn't show this effect. This can be explained by the diminished effective charge of the ammonium group in the preferred gauche conformation of the molecule.
Esterification of benzenecarboxylic acids with ethylene glycol, 11. Kinetics of the initial stage of metal‐ion catalyzed polyesterification of isophthalic acid with ethylene glycol
Authors: Nondek Lubomír , Málek Jaroslav
Published: April 2003

The kinetics of the reaction of isophthalic acid (4) with excess of ethylene glycol (5) in the presence of metal compounds as catalysts was determined in an open system and at 171–193°C by using liquid chromatography on silica gel. At an initial mole ratio of 5/4 equal to or higher than 20, the initial stage of metal‐ion catalyzed polyesterification is characterized by the absence of oligomers and involves two consecutive and two concurrent reactions, i.e., metal‐ion catalyzed and parallel uncatalyzed esterification of 4 to 2‐hydroxyethyl hydrogen isophthalate (6) and metal‐ion catalyzed and parallel uncatalyzed esterification of 6 to bis(2‐hydroxyethyl) isophthalate (7). The rate constants for all the individual reaction steps were determined. The metal‐ion catalyzed conversion of 4 to 6 (reaction (i)) is first‐order in 4 and that of 6 to 7 (reaction (ii)) is half‐order in 6; both reactions (i)–(ii) catalyzed by tin(II) oxalate are first‐order in tin(II) ions. These kinetic relations hold through at least 97% of transformation of 4 into 7. The activity of metal ions in the catalyzed esterification reactions (i)–(ii) decreases in the order Sn2+>Ti4+ ≫ Zn2+ > Pb2+ ≈ Co2+≈ Cd2+. The activation energies Ei(Sn) and Eii(Sn) for the tin(II)‐ion catalyzed reactions (i)–(ii) are 85,1±4,9 kJ mol−1 and 83,1±4,2 kJ mol−1, respectively, and the corresponding activation entropies ΔS and ΔS are −;134,1±11,0 J K−1 mol−1 and −148,6±9,5 J K−1 mol−1, respectively.
Untersuchungen zur kinetik der polykondensation von sebacoylchlorid mit α,ω‐alkandiolen
Authors: Ueberreiter Kurt , Engel Michael
Published: April 2003

The kinetics of polycondensation of sebacoyl chloride with α,ω‐alkane dioles HO—(CH2)n—OH (5⩽n⩽10) in dioxane can be described by a second order law related to the functional groups. The rate constants at a given temperature have all the same value within the accuracy of the measurements. The mean values of the rate constants are k=0,63·10−3mol−1ls−1 (T=299,9 K),k=1,19·10−3mol−1ls−1 (T=312,9 K), and k=2,98·10−3mol−1l s−1 (T=331,8 K). Thus, these polycondensation reactions are independent of the chain length of the α,ω‐dioles. The mean activation energy is EA=41 kJ mol−1 and the pre‐exponential factor is A=8,5·10×3 mol−1ls−1.
Polyelectrolyte complexes of sodium dextran sulfate with chitosan, 2
Authors: Fukuda Hiroshi , Kikuchi Yasuo
Published: April 2003

Solutions of sodium dextran sulfate and chitosan were co‐reacted under various experimental conditions to form a water‐insoluble hydrous precipitate. The mole ratios of N/S in the polyelectrolyte complexes were estimated to be 0,79 to 2,54 depending on pH as well as on the mixing ratio of the complexing components. IR spectroscopic studies, blood test, elementary analyses, color reactions with toluidine blue, and the studies on solubility revealed that two polyelectrolyte complexes, different in molecular structure, were formed: series A and B (Tab. 1), where the latter emerged at lower pH condition. It seems that the number of binding sites between NH and OSO in B series is smaller than that in A series, considering their nitrogen content or the formation of OSO3H groups in B series. Furthermore, the polyelectrolyte complexes of A series rather suppressed the coagulation of blood, whereas those of B series enhanced it. The mechanism is still not completely elucidated. Nonetheless, the experimental results appear to open an important reservoir of anti‐thrombogenetic materials whose properties may be tailored.
Rotationsebulliometer, 1. Prüfung der Apparatur
Authors: Sotobayashi Hideto , Asmussen Frithjof , Chen Jiang‐tsun
Published: April 2003

A new pressure controlled twin‐ebulliometer without Cottrellpump is described. The apparatus is equipped with rotating vessels to establish complete equilibrium between liquid and vapour. The boiling temperature can be chosen by reducing the pressure by means of a pressure regulator in the range of 100–760 Torr.

In SI‐Einheiten: 1 Torr=133,322 N/m2.

The elevation of the boiling‐point is measured by two thermistors in a Wheatstone bridge circuit.

Investigation of benzil and biphenyl in dilute benzene solution shows that the rotating ebulliometer permits operations within a boiling temperature range of 30–80°C.

Measurements of polystyrene and poly(ethylene glycol) [poly(oxyethylene)] in benzene solution show that the rotating boiling vessel avoids the formation of foam. Therefore, the elevation of the boiling‐point of solutions of polymeric samples can be measured with this apparatus.
Studies on the polymerization of vinyl compounds in the presence of metal salts, 11. The polymerization of methyl methacrylate initiated by ferric ion and thiourea or its derivatives
Authors: Narita Hiroshi , Otsuki Atsuko , Machida Seishi
Published: April 2003

The polymerization of methyl methacrylate initiated by ferric salt and thiourea in dimethyl sulfoxide solution was studied. By the substitution of hydrogen by an alkyl or aryl group in the thiourea, the rate of the polymerization decreases. The logarithm of the rate is proportional to the σ* value of Taft's equation. The results are discussed on the basis of the IR and NMR data. It was confirmed that the polymerization is initiated by a radical produced by the reaction of the ferric ion with the isothiourea which is formed from the thiourea by tautomerization. The termination of the polymerization is also discussed based on the results of kinetic studies with different kinds and concentrations of the ferric salt.
Free‐radical polymerization of methyl methacrylate initiated by N,N‐dimethylaniline
Authors: Ishida Tomohiro , Kondo Shuji , Tsuda Kazuichi
Published: April 2003

N,N‐Dimethylaniline (DMA) does initiate the free‐radical polymerization of methyl methacrylate (MMA), methyl acrylate, and methyl vinyl ketone. The overall rates of polymerization of MMA were obtained at 40, 50, and 60°C. From the results of a detailed kinetic investigation, the activation enthalpy and activation entropy of polymerization were calculated as 63,2 kJ mol−1 and −153 J mol−1 K−1 at 60°C. Rate equation was also obtained as Rp = k[DMA]1/2[MMA]3/2 and the polymerization was inhibited by benzoquinone. Though styrene alone was not polymerized by DMA, the copolymerization of MMA with styrene by DMA (reactivity ratios: rMMA=0,45 and rSt=0,50) followed a typical free‐radical mechanism. An electron‐transfer complex between DMA and MMA is proposed as the initiation species.
Influence d'une différence de réactivité entre hydroxyles primaires et secondaires sur la gélification de systèmes polyol/polyacide
Authors: Durand Dominique , Bruneau Claude‐Marcel
Published: April 2003

Using a new general formulation of Flory's gelation criterion, a critical transition equation is derived for polyol/polyacid systems having hydroxyl groups of unequal reactivity. The reaction probabilities of various hydroxyl groups are formulated from kinetic calculations. The gelation equation shows that the inclusion of monomers having groups of unequal reactivity significantly increase the extent of reaction necessary for the gelation. The theoretical forecasts are confirmed by the experimental study of some polyester systems.
On the copolymerization of polar vinyl monomers with electron donor monomers catalyzed by ethylaluminium dichloride
Authors: Florjańczyk Zbigniew , Kuran Witold , Pasynkiewicz Stanisław , Langwald Norbert
Published: April 2003

The copolymerizations of acrylonitrile and methyl acrylate with propylene, isobutylene, butadiene, styrene, and vinyl chloride and the copolymerizations of methacrylonitrile and methyl methacrylate with propylene in the presence of ethylaluminium dichloride as the complexing agent were studied. When the polar vinyl monomer is not completely complexed by ethylaluminium dichloride in the copolymerizations of acrylonitrile with propylene, isobutylene, and vinyl chloride, and in those of methacrylonitrile and methyl methacrylate with propylene, copolymers rich in polar vinyl monomer were found. In the copolymerization of acrylonitrile with propylene, the polar vinyl monomer content in the copolymer was found to increase with decreasing mole ratio ethylaluminium dichloride/acrylonitrile in the monomer feed. In the copolymerizations of acrylonitrile and methyl acrylate with butadiene and styrene and of methyl acrylate with propylene, isobutylene, and vinyl chloride, copolymers of approximately 1:1 composition are formed. The reactivity of monomers is discussed. The introduction of VOCl3 to the polymerization systems studied was found to cause an enhancement in the copolymerization yield and a decrease of the copolymer intrinsic viscosity; it has not, however, a significant influence on the copolymer composition.
Polymerization of lactams, 23. Non‐activated polymerization of 2‐pyrrolidone initiated with potassium tert‐butoxide
Authors: Roda Jan , Kmínek Ivan , Králíček Jaroslav
Published: April 2003

The non‐activated polymerization of 2‐pyrrolidone initiated with potassium tert‐butoxide (conc. range 0,24–4,97 mole‐%) was studied at 40°C. In accordance with theory, the conversion increases linearly with polymerization time and with initiator concentration. The linear dependence on conversion of the content of basic groups in the polymer and, above all, of the number of polymer molecules, and its independence on the initiator concentration up to 30% conversion indicate that a stationary state between formation and destruction of growth centres is very rapidly reached.
Kinetics and mechanism of the polymerization of cyclic acetals, 5. Spectroscopic studies of the polymer end‐groups in poly(1,3‐dioxolane)
Authors: Kubisa Przemysław , Penczek Stanisław
Published: April 2003

Polymerization of 1,3‐dioxolane (1) was initiated in CH3NO2 and CH2Cl2 solvents with benzoylium hexafluoroantimonate (C6H5CO+SbF), terminated with sodium ethanolate (C2H5ONa), and the endgroups were determined by using UV spectrophotometry and 1H NMR methods. Polymers with high polymerization degrees DPn were obtained (M̄n up to 3·105); DPn calculated for living polymerization conditions (DPn=([1]0−[1]e)/[C6H5CO+SbF]0; i.e. one molecule of initiator gives one macromolecule) agree well with DPn measured by osmometry and DPn found from 1H NMR and UV methods assuming one respective end‐ group per macromolecule. 1H NMR studies were performed on polymers from perdeuterated 1 (1,3‐dioxolane‐d6). These polymers, after purification, were shown to bear benzoyloxy and ethoxy end‐groups: \documentclass{article}\pagestyle{empty}\begin{document}${\rm C}_6 {\rm H}_5 \hbox{---} {\rm CO\rlap{--} (O} \hbox{---} {\rm CD}_2 {\rm CD}_2 {\rm OCD}_2 {\rm \rlap{--} )}_n {\rm OCH}_2 {\rm CH}_3$\end{document}

Similar results were obtained for polymers initiated with triethyloxonium hexafluoroantimonate ((C2H5)3O+SbF), and terminated with triphenylphosphine ((C6H5)3P). These results indicate that initiation with stable oxocarbenium or oxonium ions leads to predominantly linear macromolecules, while initiation with perchloric acid (according to the data reported by Plesch) leads to polymers of low molecular weight and claimed to be mostly cyclic after killing with C2H5ONa.
Functional monomers and polymers, 43. ESR study on the copper(II) complexes of polymers containing imidazolyl groups and of their monomeric analogs
Authors: Sato Masaaki , Kondo Koichi , Takemoto Kiichi
Published: April 2003

ESR spectroscopy was conducted on Cu(II) complexes of poly(1‐vinylimidazole), poly[4(5)‐vinylimidazole], and poly(2‐methyl‐1‐vinylimidazole) and compared with those of the corresponding low‐molecular‐weight Cu(II) complexes. At 293 K, an averaging of the anisotropy was observed for monomeric [Cu(imidazole)4]2+ complex, however, it was not for polymeric Cu(II) complexes. On the other hand, both monomeric and polymeric complexes showed typical asymmetric spectra of Cu(II) complex in a tetragonal coordination at 77K. Structure of the intramolecular [CuL4]2+ type of polymeric complexes was kept stable in the case if the ligand L to Cu(II) mole ratio was over 10:1, but it tended to change by increasing the pH value of the systems, with a conformational change of the polymeric ligand in aqueous solution. A distorted form was suggested for the polymeric Cu(II) complexes at lower pH.
Solution properties of poly(alanine)s, 3. 1H NMR study of poly(alanine)s in the mixture of chloroform and trifluoroacetic acid
Authors: Shoji Akira , Kawai Toru , Nishioka Atsuo
Published: April 2003

The 1H NMR spectra were studied for monodisperse alanine oligopeptides (dimer, trimer, tetramer, and nonamer) containing a butylamino group at the C‐terminal residue and for copolypeptides of D‐ and L‐alanines having sharp molecular weight distributions. The solvents used were the mixtures of deuterochloroform (CDCl3) and trifluoroacetic acid (TFA) in various compositions. The conformational transformation of poly(L‐alanine)s and the interaction between the NH protons in the oligomers and the solvents were investigated on the basis of the chemical shifts of the NH signals. For the tetramer and the nonamer, the NH protons showed “double peaks” in the compositions of helix‐supporting solvents. The most substantial change in the chemical shifts of the NH peaks occurs between the nonamer and poly(L‐alanine) with a number average degree of polymerization DPn=16, suggesting that the nature of the double peaks observed in poly(L‐alanine)s is essentially different from that observed in oligo‐L‐alanines. This finding is explained in terms of the conformational change which arises from the interaction (solvation) of NH protons with CDCl3 or TFA for the oligomers (below the nonamer) and in terms of the low transitional rate by chemical exchange for poly(L‐alanine)s.
Photochemical reactions and stabilizing properties of 2,6‐Di‐tert‐butyl‐4‐methylphenol, 1. Photochemical reactions of 2,6‐Di‐tert‐butyl‐4‐methylphenol in hexane solutions
Authors: Kowal Joanna , Waligóra Bolesław
Published: April 2003

Photochemical reactions of 2,6‐di‐tert‐butyl‐4‐methylphenol (3) in hexane solutions lead to the formation of 2,6,2′,6′‐tetra‐tert‐butyl‐4,4′‐ethylenediphenol (1) and 2,6,2′,6′‐tetra‐tert‐butyl‐4,4′‐ethanediylidenedi(2,5‐cyclohexadien‐1‐one) (2) in a mole ratio of 10:1 in the first step. The formation of acetophenone due to the decomposition of di(α,α‐dimethylbenzyl) peroxide (dicumyl peroxide) (6) is inhibited by 3 in hexane solution. The inhibiting effect of 3 is greater if the reaction is initiated by light absorbed by 6 than when it is initiated by light absorbed by both 3 and 6.
Gelchromatographie mit zwei Detektoren. Ein verfahren zur Korrektur von Gelchromatogrammen
Authors: Berger Knut C.
Published: April 2003

The relationship between the experimental function E(v) for the viscosity and the chromatogram after correction of instrumental spreading, w(v0) can be expressed by the integral equation

where v0 is the elution volume under the integral sign and D(v, v0) is a function that describes the shape of the band spreading curve of a monodisperse sample. The relationship between the experimental chromatogram e(v) is given by the Tung equation. If the function D(v, v0) is independent of the molecular weight, then it is possible to solve these equations simultaneously and to calculate the functions w(v0) and D(v, v0). A mathematical method is given.
Solvent effect on the formation of poly(methacrylic acid)‐poly(N‐vinyl‐2‐pyrrolidone) complex through hydrogen bonding
Authors: Ohno Hiroyuki , Abe Koji , Tsuchida Eishun
Published: April 2003

An interpolymer complex can be obtained by mixing the solutions of poly(methacrylic acid) and poly(N‐vinyl‐2‐pyrrolidone). Three phase changes were observed on increasing the initial polymer concentration: namely, a homogeneous solution, a precipitate, and a gel. Such interpolymer complex formations were examined in several protic and aprotic solvents. The obvious relationship between the complex formation and the dielectric constant of the solvent was eludicated. The effect of hydrophobic interactions on the complex formation was also discussed as well as the role of the α‐methyl group of poly(methacrylic acid).
Elektrokinetische untersuchungen an Fasern, 3. Zur Beurteilung von Modellen für Faserpfropfen und der Einstellzeit von Strömungspotential und Strömungsstrom
Authors: Aichele Wilfried , Schollmeyer Eckhard , Herlinger Heinz
Published: April 2003

The present paper shows that the conductivity of an arrangement of fibres in a liquid depends rather insensitively on the zeta‐potential (ζs) calculated according to the Smoluchowski equation. The reason suggested also makes doubtful the theoretical deduction of the Fairbrother‐Mastin method to correct the porosity dependence of the ζs‐potential.

An investigation of the porosity dependence of the three independent coefficients of the phenomenological equations of arbitrary fibres gives an explanation for the fact, that this relation is found to fit in the most cases with the porosity dependence of the ζs‐values. A different arrangement of fibres forming a plug shows that the use of the Smoluchowski equation cannot be expanded from capillaries to plugs using simple corrections.

Finally the time dependence of the streaming current and the streaming potential is discussed and compared with the velocity of the streaming fluid and with the electrical properties of the measuring cell.
Functional monomers and polymers, 44. A modified way to form the deoxycholic acid/2,3‐dimethyl‐1,3‐butadiene canal complex and its polymerization
Authors: Miyata Mikiji , Takemoto Kiichi
Published: April 2003

Deoxycholic acid/2,3‐dimethyl‐1,3‐butadiene canal complex was found to be prepared readily by replacing various sorts of guest molecules in the deoxycholic acid canals by 2,3‐dimethyl‐1,3‐butadiene monomer. Post‐irradiative polymerization of the monomer included in deoxycholic acid canals was studied after irradiating with γ‐rays from a 60Co source. Both the replacement and the polymerization processes were observed by differential thermal analysis (DTA), thermogravimetry (TG), and IR spectroscopy. The optimum conditions for the replacement of acetone, ethyl acetate, and acetic acid by 2,3‐ dimethyl‐1,3‐butadiene were established.
Polymerization of vinyl ethers by 3d‐transition metal oxides
Authors: Biswas Mukul , Kabir Gazi M. Ahsanul , Bhagawan Suggu Surya
Published: April 2003

Studies on the relative efficiencies of 3d‐transition metal oxides as catalysts for the polymerization of vinyl ethers revealed that V2O5 is the most efficient catalyst. Some kinetic studies with the system isobutyl vinyl ether/V2O5/benzene were carried out at ambient temperature. It was found that the rate is second order in isobutyl vinyl ether (IBVE) concentration (0,25 to 2,0mol.1−1) and the inhibition of the polymerization by pyridine suggests a cationic mechanism. Rp increases by the use of benzaldehyde along with V2O5, whereas water (3.10−3mol.1−1) seems to have no effect on Rp. Over the temperature range of 15 to 60°C, Rp as well as [η] attain a maximum value at about 32°C. [η] is unaffected by varying the amounts of oxides, whereas it increases with increasing IBVE concentration. No stereoregularity in the product polymer was observed by using V2O5 alone or in combination with modifiers such as benzaldehyde or carbon disulfide. The kinetics are interpreted in terms of the Hinshelwood‐Langmuire mechanism assuming a single point adsorption.
Radical copolymerisation of vinylidene chloride and methacrylonitrile, 1. Sequence microstructure measured by 220 MHz 1H NMR
Authors: Suggate John R.
Published: April 2003

The radical copolymerisation of vinylidene chloride and methacrylonitrile in bulk and in cyclohexanone solution was studied. The monomer dyad sequence distributions and some of the tetrad and hexad sequences were obtained from 220 MHz 1H NMR spectra of the copolymers. From the copolymer compositions and sequence information it could be shown that the copolymerisation kinetics deviate from the simple Mayo‐Lewis scheme. Small differences were found between the bulk and solution copolymerisations.
The phenyl group motion in polystyrene and a model of restricted internal rotation
Authors: Gronski Wolfram , Murayama Nobumichi
Published: April 2003

The 13C NMR relaxation functions are calculated for the case of restricted rotational diffusion of a CH dipole pair about an internal rotational axis. The model is applied to the interpretation of recent 13C experiments of polystyrene in a region where the relaxation of all C atoms of the phenyl ring exhibits the same temperature coefficient. It is concluded that the velocity of the phenyl group motion may be overestimated if complete rotation is assumed. By means of the model of restricted internal rotation one finds D/D0<0,1 for the ratio of internal and mean segmental rotational diffusion constants.
Pharmacologically active polymers, 17. Syntheses and characterization of polymeric derivatives of the antitumor agent methotrexate
Authors: Przybylski Michael , Fell Elke , Ringsdorf Helmut , Zaharko Daniel S.
Published: April 2003

Synthesis and characterization of polymeric derivatives of the folic acid antagonist, Methotrexate, N‐[4‐(N‐methyl‐2,4‐diamino‐6‐pteridinylmethylamino)benzoyl] glutamic acid (1a), a widely used antitumor agent, are described. Derivatives of poly(L‐lysine), poly(iminoethylene), poly(vinyl alcohol), and carboxymethylcellulose with various contents (3–15 mole‐%) of substituted repeating units were prepared by polymer‐analogous amidation and transesterification of the dimethyl ester of 1a and with N‐[2‐(N‐methylmorpholinio)ethyl]carbodiimide p‐toluenesulfonate as coupling reagent. By nucleophilic addition reactions of the pteridinyl amino groups under mild conditions, 1a was bound without cross‐linking to divinyl ether‐maleic anhydride (DIVEMA) copolymers of various molecular weights. This copolymer appeared to be of particular interest as carrier because of its established antitumor and immune‐stimulating activity.—With the exception of the poly(vinyl alcohol) derivative, all polymers containing the 1a residue are water soluble at the physiological pH range. Besides the dimethyl ester of 1a used as convenient starting material for polymer‐analogous reactions, further dialkyl esters of 1a were synthesized as low molecular weight model compounds for the study of the pharmacodynamic properties of polymers, substituted with 1a. The polymeric derivatives of 1a were purified by membrane filtration, solvent extraction, and reprecipitation; the polymers and the dialkylesters 1b–d were characterized by thin‐layer chromatography, IR, NMR, UV and mass spectra, and elemental analysis. Preliminary results of the pharmacological studies with the DIVEMA derivatives of 1a are also reported.
Mass spectrometrical behavior of hydrocarbons, 2. Oligododecenylenes and corresponding alkanes
Authors: Höcker Hartwig , Riebel Klaus
Published: April 2003

The mass spectra of cycloolefins (C12xH22x), cycloalkanes (C12xH24x), and unbranched alkanes are compared. The most prominent fragmentation series are CnH2(n–p)−1⊕, CnH2n − 1⊕, and CnH2n+1⊕, respectively. The intensity of the molecular ion peak decreases in the order given.
Composition dependence of the second virial coefficients for styrene/butadiene/styrene three‐block copolymers and for mixtures of the respective homopolymers
Authors: Sikora Antonín , Pouchlý Julius
Published: April 2003

The composition dependences of the second virial coefficients for styrene/butadiene/styrene three‐block copolymers with Mn≈ 105 g.mol−1 were measured in toluene, 1,4‐dioxane, isobutyl methyl ketone and isopropyl acetate at various temperatures; analogous measurements were made with mixtures of polystyrene and polybutadiene in toluene and 1,4‐dioxane. The results were qualitatively compared with model calculations based on the relations derived by means of the perturbation theory.
Optically active vinyl polymers containing fluorescent groups, 3 synthesis and characterization of optically active polymers containing carbazolyl groups
Authors: Chiellini Emo , Solaro Roberto , Ledwith Anthony
Published: April 2003

Syntheses and characterizations of polymers from the optically active vinylcarbazole derivatives (S)‐3‐sec‐butyl‐9‐vinylcarbazole (1), (S)‐9‐(2‐methylbutyl)‐2‐vinylcarbazole (2), and (S‐9‐(2‐methylbutyl)‐3‐vinyl‐carbazole)(3) are described in detail. The N‐vinyl derivative 1 gives satisfactory conversions to high polymers in the presence of both radical and cationic initiators whereas the C‐vinyl derivatives 2 and 3 give better results with ionic initiators (anionic and cationic respectively). Measurement of optical rotation and circular dichroism (CD) for all the polymers as well as corresponding monomers and low molecular weight analogs indicates that the stereochemical placements of monomeric units in the macromolecules are dependent on the type of initiators used.
Theoretical considerations on the formation of graft copolymers by coupling reaction
Authors: Ishizu Koji , Fukutomi Takashi , Kakurai Toshio
Published: April 2003

The effects of various factors on the rate constant of each addition step for the formation of graft copolymers by coupling reactions were considered theoretically. The progressively decreasing rate constant of the addition was considered as a problem of the segment density of branched chains around the functional groups of the backbone molecule, assuming that the spacial distribution of the segments is in equilibrium and the formation of the graft copolymer follows a Markovian process. The rate constant of each stage obtained in coupling of the polystyryl anion with chloromethylated polystyrene was compared with the results derived from the theoretical treatment. These results are discussed in some detail.
The photo‐decomposition of polystyrene containing in‐chain peroxide links.—solvent effects
Authors: Weir Neil A. , Milkie Terence H.
Published: April 2003

The photodegradation of styrene‐oxygen copolymers on irradiation with ultra violet light (λ>300 nm) has been studied using a range of solvents. Rates of degradation of the copolymers are dependent on the solvent. An investigation of the contributing factors to the effect of solvent on the rate of chain scission has been made and a correlation between degradation rate and the reactivity of the solvent as a transfer agent has been observed. Other factors, including solution viscosity appear to be relatively unimportant.
Reaktive mikrogele, 8. Anionische polymerisation von ethylendimethacrylat
Authors: Straehle Wolfgang , Funke Werner
Published: April 2003

By polymerisation of ethylene dimethacrylate with n‐butyllithium in solution reactive microgels have been obtained. These EDMA‐microgels are nearly spherical, have a broad distribution and are easily swellable in organic solvents. The macrogelation depends on the amount of solvent between the microgel particles.