bluuebunny/crossref_metadata_2025 huggingface dataset:
Pharmacologically active polymers, 11. Polymeric sulfonamides as potential antibacterials and carriers for antitumor agents
Authors: Hofmann Volker , Przybylski Michael , Ringsdorf Helmut , Ritter Helmut
Published: April 2003

A number of acryl and methacryl derivatives of different sulfanilamides (1a—I) were prepared and polymerized. The fixation of the sulfonamide to the polymerizable group was carried out directly, using the acryl‐ and methacrylamides, and by means of spacer groups, to favour the enzymatic or hydrolytic release of the drug moiety. Selected sulfonamide types of different pKA values were used, and the pH‐dependant solubility of the corresponding polymers was studied.

The monomeric acryloyl and methacryloyl sulfonamides were homopolymerized radically by AIBN. For distribution studies polysulfadiazineacrylamide, 14C‐labelled in the main chain (2e'), was synthesized. Copolymerization with 2‐methylsulfinylethyl methacrylate (5a) yielded water soluble polymers of lower toxicity. Eventually biodegradable polymers containing sulfonamide units in the backbone were obtained by anionic polymerization of acryloyl and methacryloyl sulfanilamide.

The new monomers and polymers were characterized by elemental analysis, IR‐ and NMR‐spectroscopy, pyrolysis mass spectrometry, and hydrolytic degradation.
Über poly[1‐N‐(4‐isothiocyanatophenyl)carbamoyloxy‐methyläthylen‐co‐1‐hydroxymethyläthylen]e als träger zur immobilisierung von papain
Authors: Manecke Georg , Pohl Robert
Published: April 2003

Durch Reaktion von Poly(allylalkohol) (2) mit 4‐Isothiocyanatophenylisocyanat (3) wurden Poly[1‐N‐(4‐isothiocyanatophenyl)carbamoyloxymethyläthylen‐co‐1‐hydroxymethyläthylen]e (5a–c) hergestellt, die in einigen Fällen durch Umsetzung mit 1,4‐Phenylendiisocyanat (4) zu 5d oder 5e vernetzt werden konnten. Diese reaktiven Träger ließen sich zur Immobilisierung von Enzymen mittels kovalenter Bindung verwenden. Das Bindungsvermögen dieser Polymeren 5a–e für Butylamin, 3,4‐Dichloranilin, Pepton (aus Lactalbumin) und Papain wurde untersucht. Vom immobilisierten Papain wurden die Enzymaktivitäten, das pH‐Optimum, die scheinbare Michaelis‐Konstante KM(app) und die Abhängigkeit der Aktivität von der Temperatur bestimmt.
The formation of oligomers in the thermal copolymerisation of the styrene/acrylonitrile‐system
Authors: Kirchner Kurt , Schlapkohl Heinz
Published: April 2003

In the thermal copolymerisation of styrene with acrylonitrile, a Dields‐Alder addition of the two monomers first takes place. The adduct reacts with a further monomer molecule, forming trimers and initiator radicals. This results from the structure of the trimers and the kinetics of their formation. The initiating step is, therefore, analogous to the polymerisation of pure styrene.
The adiabatic compressibility of polyelectrolytes: Binding of Na+ ions on the multivalent site of polymer chains
Authors: Dewhare Anil R. , Roy‐Chowdhury Phanibhusan
Published: April 2003

The adiabatic compressibility of a 1:0,35 acrylic acid/maleic acid copolymer (AA/MA) and of its three “sodium salts” obtained by neutralizing (25%, 50% and 100%) with sodium hydroxide was studied. In 100% neutralized AA/MA copolymer, the dissociation of the counter ions was complete so that the limiting values of the apparent molal compressibility δK and apparent molal volume δV were found to be lowest with values of −83,0·10−4 cm3 bar−1 mol−1 and 52,9 cm3/mol respectively. This showed a decrease of 89,0·10−4 cm3 bar−1 mol−1 and 20,9 cm3 mol−1 from that of the unneutralized acid copolymer. The δK and δV values were resolved into the ionic components, δK and δV. The electrostriction caused in the copolymer by an increase of the negative charge from 0 to −0,425, from −0,425 to −0,85 and from −0,85 to −1,7 produced a decrease of 3,9.10−4, 6,9.10−4, and 5,7.10−4 cm3 bar−1 mol−1 in δK and 3,7,4,5 and 10,2 cm3 mol−1 in δV. Contrary to the volume change, the compressibility data showed a disproportionate decrease for the neutralized products. The reduced viscosity for the sodium salts was also found to have reduced values. A notable point emerging from this study is that the apparent ion binding on the multivalent site of the polymer chain, as obtained by the two methods—the adiabatic compressibility and density determinations—shows an appreciable variation.
Strukturuntersuchungen an adsorptionsschichten makromolekularer stoffe, 3. Untersuchung der struktur von adsorptionsschichten unverzweigter polyester an siliciumdioxidoberflächen
Authors: Dietz Erwin
Published: April 2003

Die Adsorptionsstruktur von Polyestern an verschiedenen Aerosiloberflächen in CHCl3 wird durch Aufnahme von Adsorptionsisothermen und IR‐spektroskopische Bestimmung der Adsorptionswechselwirkung untersucht. Vergleiche zwischen den Bruchteilen gebundener Kettencarbonylgruppen der Polyester und der entsprechenden Abnahme an oberflächenständigen, freien SiOH‐Gruppen zeigen, daß die Ausbildung von Wasserstoffbrückenbindungen zwischen Carbonyl‐ und SiOH‐Gruppen nicht in einem stöchiometrischen Verhältnis erfolgt. Bei niedriger Oberflächenbelegung werden Carbonylgruppen bevorzugt an freie (geminale) Silanolgruppenpaare adsorbiert. Mit zunehmender adsorbierter Menge nimmt bei allen Polyestern die Haftstellenzahl ab. Die Größe der bei der Adsorption ausgebildeten Schlaufen hängt im wesentlichen von der Anordnung der Adsorptionsplätze auf der Aerosiloberfläche und von der Verteilung der adsorbierbaren Gruppen im Makromolekül ab. Die Bildungswärme der bei der Adsorption ausgebildeten Wasserstoffbrückenbindung wird mit Hilfe einer empirischen Formel aus der Verschiebung der IR‐Absorptionsbanden der SiOH‐Gruppen berechnet und beträgt je nach Polyester zwischen 21 und 26kJ mol−1.
Some observations on the interpretation of ESCA spectra of fluorine containing polymers and their relation to the degree of crystallinity, to the surface tension, and to the content of adsorbed gas
Authors: Adams David , Clark David , Dilks Alan , Peeling James , Thomas Herbert Ronald
Published: April 2003

An analysis is presented of recently published data concerning the ESCA spectra of some fluorine containing polymers. The claim that the ESCA data may be directly related to degree of crystallinity and to surface tension and content of adsorbed gas is examined and shown to be incorrect.
Solution polymerization of 1,3,5‐trioxane and 1,3,5,7‐tetroxocane, 1. Rate of polymerization, characterization and melting behaviour of as‐polymerized poly(oxymethylene)
Authors: Muñoz‐Escalona Antonio , Guerrero Saul J.
Published: April 2003

A relationship between the rate of polymerization and the structure of the as‐polymerized crystals is investigated in the cationic polymerization in solution of 1,3,5‐trioxane and 1,3,5,7‐tetroxocane. The monomer/solvent reaction systems chosen were: 1,3,5,7‐tetroxocane/nitrobenzene (I); 1,3,5,7‐tetroxocane/l,2‐dichloroethane (II), 1,3,5‐trioxane/chlorinated parafin (III), and 1,3,5,7‐trioxane/normal paraffin (IV). The poly(oxymethylene), (POM), obtained in each case was characterized as to molecular weight, X‐ray cristallinity and by differential scanning calorimetry (DSC). The data from the DSC curves indicated a folded chain structure for systems I and II, where the rate pf polymerization was very high. However in system II at high polymer conversion a fraction of POM appears with a melting behaviour characteristic of an extended chain structure. For systems III and IV, where the rate of polymerization was very low, the DSC curves indicated the presence of two crystal forms. One of these forms shows a clear response to overheating and annealing treatments, which indicates the presence of an extended chain structure. The second form shows ambiguous melting behaviour and by thermal data alone it is impossible to determine its structure.
Die Bestimmung der Molekulargewichtsverteilung von Poly(methylmethacrylat)en durch Gegenstromverteilung in flüssigen Phasenpaaren
Authors: v. Tavel Peter , Rüfenacht Hans Jakob
Published: April 2003

Drei polydisperse Poly(methylmethacrylat)e werden mittels Gegenstromverteilung fraktioniert und ihre Molekulargewichtsverteilungen bestimmt. Ihre mittleren Molekulargewichte M̄w betragen ca. 30 000, 130 000 und 540 000. Als Phasenpaare dienen fast kritische Gemische von Aceton (ca. 70. Vol.‐%), Hexan (ca. 22%) und Wasser (ca. 8%) mit einem Phasendichteunterschied von 0,03 bis 0,05g/cm3, denen zur Einstellung eines günstigen mittleren Verteilungskoeffizienten wenig Benzol zugesetzt wird. Die gemessene Molekulargewichtsverteilung von Präparat 130 000 stimmt mit derjenigen, die in der Ultrazentrifuge bestimmt wurde, überein. Die Gelpermeationschromatographie liefert wesentlich breitere Verteilungen. Die aus den Verteilungen berechneten Uneinheitlichkeiten Mw/Mn betragen für die Gegenstromverteilung 1,45, die Ultrazentrifugierung 1,46 und die Gelpermeationschromatographie 1,98, diejenige typischer Fraktionen 1,02 bis 1,05.
Formation of polyglycine crystals in the course of polymerization of glycine N‐carboxy anhydride initiated by primary diamines
Authors: Khair B. M. Abo‐El , Kōmoto Tadashi , Kawai Tohru
Published: April 2003

The heterogeneous polymerization of glycine N‐carboxy anhydride (2,5‐dioxo‐1‐oxa‐3‐azacyclopentane) was carried out in acetonitrile using various kinds of primary diamines as initiators such as ethylene diamine (ED), hexamethylenediamine (HM) and bis(4‐aminophenyl) ether (AP) comparing with butylamine previously reported. Electron microscopic observations revealed that most of the precipitates were spherulites. The conformation of polyglycine obtained from all the initiators used, was in the form of polyglycine I. The apparent crystallinity of the resultant polymer was low in the case of AP‐as compared with ED‐or HM‐initiated polymerizations. A growth mechanism of polyglycine crystals formed in the course of polymerization has been proposed.
Branching in free radical polymerization due to chain transfer. Application to poly(vinyl acetate)
Authors: Wolf Christine , Burchard Walther
Published: April 2003

A general statistical theory in direct relation to the kinetics of polymerization is developed for free radical polymerization with chain transfer. In the present paper this relationship is displayed in detail; analytical expressions are derived for the probabilities of reaction as functions of the reaction rates and the monomer conversion. The statistical treatment (cascade theory) of the polyreaction allows the calculation of the weight average degree of polymerization Pw, the z‐average mean square radius of gyration 〈S2〉z, and the particle scattering factor Pz(θ). While for linear chains the mentioned averages are determined by a single link probability, in the branched system these averages are characterized by a stochastic matrix whose elements are the various link probabilities. The theory is applied to poly(vinyl acetate). A good agreement is obtained with the experimental results of D. J. Stein for this polymer.
Inorganic coordination polymers, 20. Zinc(II) phosphinate polymers and copolymers containing phenyl sulfone side groups
Authors: Nannelli Piero , Gillman H. D. , Monsimer Harold G. , Advani Shyam B.
Published: April 2003

The syntheses and characterizations of a series of new phosphinic acids and the zinc polymers and copolymers prepared from them are reported. These compositions are characterized by the presence of phenyl sulfone side groups. The zinc derivatives were found to be among the thermally most stable tractable poly(metal phosphinates) yet studied.
Carbon‐13 and proton magnetic resonance studies of poly(N‐vinylcarbazole) in solution
Authors: Tsuchihashi Nobuaki , Hatano Masahiro , Sohma Junkichi
Published: April 2003

Spin‐lattice relaxation times T1 of individual carbons and protons were measured by the partially relaxed Fourier transform (PRFT) method for poly(N‐vinylcarbazole) in solution. The 13C‐T1 value of the methylene carbon is about one‐half of that of the methine carbon, and the carbazolyl CH carbons have T1 values close to that of the skeletal CH carbons. The effective correlation time for the skeletal carbon is estimated as ca. 0,95 ns on the basis of the measured T1 and 13C‐1H nuclear Overhauser effect (NOE) factor. Moreover, the 13C normal Fourier transformation (NFT) spectrum and proton T1 indicate strong steric interactions between the pendant carbazolyl groups in the polymer. The results demonstrate that the polymer in solution has a rigid local structure with hindered internal rotation of the bulky side‐chain groups.
Neue 8‐chinolinol‐haltige polykondensate und polymerisate
Authors: Idel Karsten , Freitag Dieter , Vernaleken Hugo
Published: April 2003

Durch Friedel‐Crafts‐Alkylierung aromatischer Systeme mit komplexbildenden Zentren gelangt man direkt zu funktionell einkondensierbaren und nach Modifizierung zu polymerisierbaren Komplexbildnern.

Die Alkylierung von 8‐Chinolinol mit p‐Isopropenylphenol oder p‐Isopropenylanilin führt zu neuen funktionellen 8‐Chinolinolen, (8a, b), die bei Polykondensationen als Kettenabbrecher reagieren und hochmolekulare, thermoplastische Polykondensate mit 8‐Chinolinolendgruppen erstmals leicht zugänglich machen. Bei der Umsetzung von Metallverbindungen mit den komplexbildenden Polykondensaten werden kettenverlängerte Polymere mit koordinativen Metallbrücken erhalten.

Die Acylierung der funktionellen 8‐Chinolinole mit Methacrylsäurechlorid ergibt neue Vinylmonomere mit 8‐Chinolinolgruppen, (9a, b), die leicht zu Homo‐ und Copolymerisaten mit seitenständigen 8‐Chinolinolgruppen weiterverarbeitet werden können. Diese komplexbildenden Polymerisate zeigen insbesondere für Schwermetalle gute reversible Austauschereigenschaften. Die metallhaltigen Polymerisate besitzen vielfache Anwendungsmöglichkeiten und können z. B. als Depotdünger oder elektronenmikroskopische Kontrastierungsmittel eingesetzt werden.
Untersuchungen zur kettenbewegung von cis‐1,4‐ und cis‐trans‐1,4‐polybutadien durch 13C‐relaxationsmessungen
Authors: Gronski Wolfram , Murayama Nobumichi
Published: April 2003

Aus 13C‐NMR‐Spektren von cis‐1,4‐Polybutadien wurden Spin‐Gitter‐Relaxationszeiten (T1), Spin‐Spin‐Relaxationszeiten (T2) und Kernoverhauserverstärkungsfaktoren (NOEF) in Lösung und temperaturabhängig im festen Zustand ermittelt. Das konstante hohe T1/T2‐Verhältnis und der konstante reduzierte NOEF weisen darauf hin, daß die Kettenbewegung sich mit abnehmenden Restriktionen nicht der inkohärenten Mikrobrownschen Bewegung niedermolekularer Flüssigkeiten annähert. 13C‐T1‐Messungen an festem cis‐trans‐1,4‐Polybutadien zeigen verschiedene Temperaturabhängigkeiten für cis‐ und trans‐Einheiten. Mit zunehmender Verdünnung bleibt das Verhältnis der T1‐Werte von Methin‐ und Methylen‐C‐Atomen (T1,CH/T) der cis‐Einheiten konstant, während das entsprechende Verhältnis der trans‐Einheiten zunimmt. Es wird geschlossen, daß die mittlere Zahl der Struktureinheiten in voneinander unabhängig sich bewegenden Kettensegmenten stark reduziert ist. Das unterschiedliche Relaxationsverhalten von cis‐ und trans‐Struktureinheiten wird als Folge unterschiedlicher Rotationsbarrieren der Einfachbindungen zwischen Methin‐ und Methylen‐C‐Atomen in diesen Einheiten gedeutet.
Pharmakologisch aktive Polymere, 14. Modellsysteme zur Untersuchung der Abspaltung niedermolekularer Komponenten von polymeren Pharmaka
Authors: Netter Karl Joachim , Ringsdorf Helmut , Wilk Hans‐Christof
Published: April 2003

Es wurden Polymere dargestellt, in denen 4‐Biphenylylamino‐, N‐(4‐Sulfamoylphenylazophenyl)amino‐ und 4‐Sulfamoylphenylazophenyloxy‐Gruppen entweder direkt oder über eine ionische Spacergruppe kovalent an die Polymerkette gebunden sind. Die polymeren 4‐Biphenylylamino‐Derivate wurden als Modellsubstanzen zur Messung der Abspaltungsgeschwindigkeit von Pharmaka in vitro und nach intraperitonealer Applikation bei Ratten pharmakologisch untersucht.
The limitations of the paracrystalline model of disorder
Authors: Brämer Rainer , Ruland Wilhelm
Published: April 2003

The basic concept of the paracrystalline disorder model is revised and its applicability to disordered structures, notably liquids and amorphous materials, is examined.

The concept of the ideal paracrystal can be considered useful provided its application is restricted to a semi‐quantitative interpretation of anisotropic disorder structures; its applicability to liquid structures and amorphous structures with homogenous density fluctuations is very limited.

The concept of the real paracrystal does not appear to be an improvement over that of the ideal paracrystal.
Etherification of poly(oxymethylene)‐diol [α‐hydro‐ω‐hydroxypoly(oxymethylene)] with orthoesters in the presence of Lewis acids
Authors: Colombo Paolo , Radici Pierino , Custro Sergio , Ermoni Mario
Published: April 2003

Attempts were made to elucidate experimentally the behaviour of poly(oxymethylene)‐diol [α‐hydro‐ω‐hydroxypoly(oxymethylene)] in the etherification reaction in order to explain the decrease of the polymer molecular weight compared with that of the starting product and in order to determine the type of terminal groups and how the thermal resistance and alkali stability can be affected. In fact one finds that, in addition to the wanted terminal ether groups, formyl and orthoformyl (dialkoxymethyl) groups are formed having a different chemical resistance in comparison to that of the pure ethers, particularly in basic media.
Ring inversion in a p‐alkylphenol‐formaldehyde cyclic tetracondensate
Authors: Munch John H.
Published: April 2003

The temperature‐dependent 1H NMR spectrum of cyclo{tetrakis[(2‐hydroxy‐5‐(1,1,3,3‐tetramethylbutyl)‐1,3‐phenylene)methylene]} 1e, a 4‐(1,1,3,3‐tetramethylbutyl)phenolformaldehyde cyclic tetracondensate, is described. From this the activation parameters in chloroform at 25°C for ring inversion (turning the pyramid inside out) of the truncated pyramid conformation of 1e were calculated: ΔG≠ = 16,03 kcal/mol (67,1 kJ/mol), ΔH≠ = 26,1 kcal/mol (109 kJ/mol), and ΔS≠ = 34 cal mol−1 K−1 (141 J mol−1 K−1). The 1H NMR spectrum of the corresponding tetraacetate 2 was found to be essentially independent of temperature.
Free radical polymerization of unconjugated dienes, 16. Temperature dependence of the cyclization ratio of the cyclopolymerization of methacrylic anhydride
Authors: Chiantore Oscar , Camino Giovanni , Chiorino Anna , Guaita Marino
Published: April 2003

The temperature dependence of the cyclization ratio of the free radical cyclopolymerization of methacrylic anhydride in chloroform solutions was investigated. The experimental difference between the activation entropy of the intramolecular cyclization and the activation entropy of the intermolecular addition of the growing chain radical onto a monomer molecule was found to agree satisfactorily with the difference calculated on the basis of a semiempirical method. It came out that, even in the present case, the intramolecular cyclizations are favoured over the intermolecular additions by a smaller entropy decrease.
Polymerization of styrene catalyzed by trifluoromethanesulfonic acid. Conductivity, spectroscopic, and kinetic measurements
Authors: Chmelir M. , Cardona N. , Schulz G. V.
Published: April 2003

The solution polymerization of styrene in methylene dichloride catalysed by trifluoromethanesulfonic acid takes place at a high rate even at low catalyst concentration. The S‐shaped course of the conversion curves is explained by a reaction mechanism, in which the catalyst rapidly forms an inactive complex with one monomer molecule, and this monomer‐acid complex is in equilibrium with the free catalyst molecule from which the propagating species are formed. Therefore, the formation of active initiating species becomes a slow process which depends also on the change of monomer concentration during polymerization. It is assumed that the active initiating species are formed from two or three molecules of acid and this process is supposed to be a determining step in the mechanism of the styrene polymerization.

The conductivity of the polymerizing system is caused probably by at least two species: firstly by the 1‐aralkyl‐3‐phenylindanyl cation which was found by means of UV spectroscopy and which is formed during and after the polymerization as product of termination reaction; secondly by another species, which takes part, as we assume, in the propagating process, probably as polystyryl carbcation.
Terpolymerization of vinyl compounds in the presence of lewis acids
Authors: Kuran Witold , Pasynkiewicz Stanisław , Nadir Riad
Published: April 2003

The terpolymerization of polar vinyl monomers, such as acrylonitrile or methacrylonitrile and methyl acrylate or methyl methacrylate with butadiene or styrene in the presence of ethylaluminium, aluminium, zinc(II), or stannum(IV) chlorides has been investigated. The yield and composition of the terpolymers as well as the yield of the Diels‐Alder reaction by‐products were determined. The copolymerization between two polar vinyl monomers in the presence of ethylaluminium dichloride or zinc(II) chloride was also carried out and the yield and composition of the copolymers produced were determined. The effect of the complexation of polar vinyl monomers by Lewis acids on the yield and monomer composition of the terpolymers produced in the investigated ternary systems is discussed in terms of the reactivities of these monomers (complexed by Lewis acids in alternating copolymerization) and competitive Diels‐Alder reactions with butadiene, as well as in terms of the copolymerization reactions between them.
Effect of metal ion on the radical polymerization of methyl methacrylate
Authors: Sugiyama Kazuo , Lee Show‐Wei
Published: April 2003

The polymerization of methyl methacrylate (MMA) initiated by azoisobutyronitrile (AIBN) in the presence of various metal chlorides and water was investigated in N,N‐dimethylformamide (DMF). The order of catalytic activity of the metal chlorides for the polymerization of MMA is as follows:

A complex formation between poly(methyl methacrylate) (PMMA) and the metal ions was observed from the measurement of the solution viscosity of PMMA in the presence of the same metal ions in DMF.
Radical copolymerization of cyclic acetals derived from acrolein, 1. Copolymerization with acrylonitrile and α‐chloroacrylonitrile
Authors: Acosta José Luis , Mateo José Luis , Sastre Roberto
Published: April 2003

Copolymerizations of 2‐vinyl‐1,3‐dioxane (1a), 5,5‐bis(hydroxymethyl)‐2‐vinyl‐1,3‐dioxane (1b), and 5,5‐dimethyl‐2‐vinyl‐1,3‐dioxane (1c) with acrylonitrile (AN) and α‐chloroacrylonitrile (CPAN) in N,N‐dimethylformamide (DMF) were investigated. For the AN(M1)/1a (M2), AN(M1)/1b (M2), and AN (M1)/1c (M2) pairs, the copolymerization parameters r1 are 5,2, 3,7, and 3,9, respectively. For the CPAN (M1)/1a (M2), CPAN (M1)/1b (M2), and CPAN (M1)/1c (M2) pairs, the r1 values are 7,95, 7,80, and 8,90, respectively. In all cases the r2 value is approximately zero. A clearly different influence of the monomer feed composition on the copolymerization rate is observed when the reaction takes place in the absence of solvent compared with that made in DMF. The explanation is related with the existence of associations between acrylonitrile or x‐acrylonitrile and the vinyl‐dioxane compound.
Solvent effect on the 13C NMR chemical shifts of meso and racemic 2,4‐dichloropentanes as the model compounds of poly(vinyl chloride)
Authors: Ando Isao , Kato Yoshiharu , Kondo Masahiro , Nishioka Atsuo
Published: April 2003

The 13C NMR chemical shifts of meso and racemic 2,4‐dichloropentanes as the model compounds of poly(vinyl chloride) in various solvents were observed, and were well interpreted theoretically by means of “solvaton”‐MO theory.

The temperature dependence of the chemical shifts in pentachloroethane and dimethyl sulfoxide solutions were also well interpreted theoretically. Further, the similarity between these behaviours of the dimers and the polymer was discussed.
Small‐angle X‐ray scattering study on concentration dependence of polymer chain dimension
Authors: Hayashi Hisao , Hamada Fumiyuki , Nakajima Akio
Published: April 2003

The concentration dependence of polymer chain dimensions was studied by a new type of “tagged polymer method” in small‐angle X‐ray scattering. A small fraction of partially iodinated polystyrene, the tagged polymer, was mixed with polystyrene in toluene. From the excess scattering originated from the iodine, the radius of gyration of the polystyrene chain (Mv = 110000) was estimated at various concentrations. It was found that the chain dimension decreases first rapidly and then decreases gradually with increasing polymer concentration, and that, in the bulk, it coincides with the unperturbed chain dimension. The result was compared with theoretical predictions. The theories applicable to low concentrations could predict well the chain dimension upto mass concentrations of ca.0,1 g/cm3, while the theories applicable to higher concentrations could not predict well the chain dimension at high concentrations. The conformation of the polymer chain was also discussed. More compact conformations than a random coil as well as the bundle model were not supported by the results.
Die Bestimmung der Molekulargewichtsverteilung von nichtkristallisierenden Polymeren mit dem Elektronenmikroskop, 5. Bestimmung der Masse der Einzelmoleküle und Aufnahme der Molekulargewichtsverteilung
Authors: Koszterszitz G. , Schulz G. V.
Published: April 2003

A method is described for the determination of the molecular weight distribution (MWD) of various polymers from electron microscopy pictures of their molecules. It is shown, that the number of molecules needed to construct the distribution is between 200 and 300. Furthermore, with macroscopic density of the polymer and the volume determined by electron microscopy, the correct mass of a single molecule is obtained. The method is demonstrated for samples of polystyrene and poly(methyl methacrylate) and the results are compared with those of GPC‐measurements.
Réactions primaires de dégradation oxydante au cours de l'autoxydation du poly(oxytétraméthylène) à 25°C, 2 Cinétique de la production d'éthylène
Authors: Thomassin Claude , Marchal Jean
Published: April 2003

The kinetics of the production of ethylene during the radiation induced autoxidation of poly(oxytetramethylene) were determined in chloroform solution at 25°C. It was found that the primary oxidative degradation of the polymer generating ethylene is part of a chain reaction process.
Réactions primaires de dégradation oxydante au cours de l'autoxydation du poly(oxytétraméthylène) à 25°C, 4 Discussion du schéma réactionnel
Authors: Thomassin Claude , Marchal Jean
Published: April 2003

Results from previous publications of the series are interpreted and discussed in terms of a reaction scheme. Probabilities of the different non‐terminating reactions of α‐alkoxyalkylperoxy radicals during the autoxidation of solutions of poly(oxytetramethylene) 10−2 g cm−3 ≤ c ≤ 6.10−2 g cm−3 were determined as follows: for the H atom abstraction = 0,2–0,4, for the monomolecular decomposition (reference) = 1, and for the non‐terminating bimolecular reaction = 7–10.
Polymerisation of trioxane, 3. Kinetics of the reaction initiated by stannic chloride and phosphorous oxychloride
Authors: Raman Puthuruthy S. , Mahadevan Venkatanarayana
Published: April 2003

The kinetics of polymerisation of 1,3,5‐trioxane initiated by stannic chloride and phosphorous oxychloride were investigated in the solvents chlorobenzene, o‐dichlorobenzene, trichloroethylene, and tetrachloroethylene. With pure reactants no induction periods were observed. The kinetic and equilibrium parameters were evaluated.
Branching in free radical polymerization due to chain transfer, 2. Theory of the effect of polyfunctional transfer reagents
Authors: Ullisch Bernd , Burchard Walther
Published: April 2003

Polyfunctional chain transfer reagents applied in free radical polymerization have two effects on the polymer molecular weight. As in the case of monofunctional regulators the chain length is reduced; the polyfunctionality of the transfer reagents causes, however, branching and thus an increase in molecular weight. A general theory is developed on the basis of Cascade Theory to describe the polymer structure in dependence on the monomer conversion. The theory takes advantage of the graph theoretical concept of digraphs by which the directed chain reaction can be properly represented. Analytic equations are derived for the weight average molecular weight Mw, z‐average mean square radius of gyration 〈S2〉z and the average particle scattering factor Pz(μ). Furthermore, a simple equation is given for the condition of gelation. Special concern is given to the formation of fractions of branched and linear polymers during the polymerization process. The derived equations are discussed in terms of kinetic constants known for polystyrene. Gelation is shown to be possible for a chain transfer constant of Ctr = 22 if the number of functional groups per transfer molecule exceeds at least a value of 7.
Branching in free radical polymerization due to chain transfer, 3. Polymerization of styrene in the presence of a tetrafunctional chain transfer agent
Authors: Ullisch Bernd , Burchard Walther
Published: April 2003

The effect of neopentanetetrayl tetrakis(2‐mercaptoacetate) on the molecular weight of polystyrene in free radical polymerization was studied. Polymerization experiments were carried out at three different concentrations of the tetrafunctional transfer reagent and were followed to monomer conversions up to β = 25%. For comparison, runs of polymerization were made without added transfer reagent and with a monofunctional 2‐mercaptoacetate, respectively. An apparent extent of branching was calculated from the molecular weights Mw obtained with the tetrafunctional and the monofunctional transfer reagent at fixed monomer conversion β and fixed concentration of reagent groups. This apparent extent of branching passes through a maximum at very small β and approaches the value 1 for large β. The decrease in the extent of branching is shown to be caused by the increasing fraction of linear polystyrene as the transfer reagent becomes exhausted.

The data observed were compared with curves calculated from Cascade Theory with the known kinetic constants for polystyrene. A very good agreement between theory and experiment is observed at medium concentration of transfer groups. At smaller concentrations the increase in Mw is less than that predicted, and at large concentrations the increase in Mw is stronger than expected by theory. The deviations are attributed to negative and positive substitution effects.
A polymer model of lignin (D.H.P.) 13C selectively labelled at the benzylic positions: Synthesis and NMR study
Authors: Gagnaire Didier , Robert Danielle
Published: April 2003

D.H.P. polymer model of Lignin was synthesized by enzymatic dehydrogenation of coniferyl alcohol enriched to 90% in 13C‐γ, on the benzylic position. On the 1H NMR spectrum recorded at 250 MHz, of the 13C labelled D.H.P., the study of the JCH‐γ couplings, made possible a precise assignment of proton signals. The 13C NMR spectra showed that the 13C‐γ carbon atom previously labelled in coniferyl alcohol was found in several sites in the polymer. Special NMR techniques like gate decoupling and selective proton irradiation were used together with the study of the chemical shifts, to make an assignment for the different 13C‐γ signals. C‐γ in carbonyl compounds like vanillin and vanillic acid, C‐γ vinylic atom like in coniferyl alcohol and cinnamaldehyde. C‐γ atom like in β5, ββ, βO4 dilignol units, and C‐γ atom involved in C‐γ benzyl ether bond in βO4 dimer were identified; the corresponding JCH–γ couplings of these C‐γ carbon atoms were determined.
Étude par spectroscopie ESR de la photodégradation de la poly(vinyl‐2 pyridine) et des copolymères vinyl‐2 pyridine/méthacrylate de méthyle
Authors: Quaegebeur Jean Pierre , Lablache‐Combier Alain , Chachaty Claude
Published: April 2003

Irradiation of films of poly(2‐vinylpyridine), (poly[1‐(2‐pyridyl)ethylene]), and poly(4‐vinylpyridine), (poly[1‐(4‐pyridyl)ethylene]) at wavelengths λ > 300 nm gives rise to the corresponding vinylpyridinyl and azabenzyl radicals, the concentrations of which do not exceed 1015 spins/g. Introduction of naphthyl substituents into the polymer chain enhances appreciably the rate of radical formation from the copolymer. Irradiation at 254 nm of poly(methyl methacrylate), (PMMA) and its copolymers containing various amounts of 2‐vinylpyridine monomeric units shows that the presence of pyridyl groups along the chain of PMMA reduces the rate of accumulation of radicals. This result is ascribed to the screening effect of pyridine. The photoprotection by the pyridyl ring is likewise observed in the phenanthrene sensitized photolysis at λ > 300 nm of the various 2‐vinylpyridine/methyl methacrylate copolymers and its mechanism is discussed.
Reaktive Mikrogele, 7. Hydroxylgruppenhaltige Mikrogele
Authors: Seitz Ulrich
Published: April 2003

The pendant vinyl groups of reactive microgels prepared from 1,4‐divinylbenzene or divinylbenzene mixture were converted into hydroxyl groups by hydroboration with diborane. This reagent enters very fast into the network of the microgels and reacts with all vinyl groups.
Reaktion an Ziegler‐Natta‐Katalysatoren, 14. Anwendung der Olefin‐Metathese zum Nachweis einer Grignard‐Wurtz‐reaktion an hydrobromiertem 1,4‐Polybutadien
Authors: Kathan Wolfgang , Wedam Othmar A. , Hummel Klaus
Published: April 2003

1,4‐Polybutadiene was partially hydrobrominated in the presence of AlBr3. A Grignard‐Wurtz‐reaction with phenylmagnesium bromide resulted in an exchange of the bromine atoms for phenyl groups. The polymers were degraded in an olefin metathesis reaction with 4‐octene using a WCl6/Sn(CH3)4 catalyst. The low molecular degradation products with bromine or phenyl substituents, resp., were separated by gas chromatography and identified by mass spectrometry.
Reaktion an Ziegler‐Natta‐Katalysatoren, 15. Einführung von halogenierten Aralkyl‐Gruppen in 1,4‐polybutadien und metathese‐abbau der modifizierten polymeren
Authors: Demel Hans , Hummel Klaus
Published: April 2003

1,4‐Polybutadiene was partially aralkylated with halogenated alkylbenzenes (4‐fluorotoluene, 2‐, 3‐, and 4‐chlorotoluene, 4‐bromotoluene, 2‐chloro‐p‐xylene, 2,4‐dichlorotoluene, 3,4‐dichlorotoluene) and dicumyl peroxide. The modified polymers were investigated by IR‐spectroscopy and degraded by olefin metathesis reaction with 4‐octene. The degradation products were separated by gas chromatography and identified by mass spectrometry. In addition to the aralkylation methylation of the 1,4‐polybutadiene occurred.
Synthesis of 2,3,4‐tri‐O‐benzyl‐[1→6]‐α‐D‐glucopyranan and [1→6]‐α‐D‐glucopyranan with high molecular weight by polymerization of 1,6‐anhydro‐2,3,4‐tri‐O‐benzyl‐β‐D‐glucopyranose
Authors: Uryu Toshiyuki , Tachikawa Hiromichi , Ohaku Ken‐Ichi , Terui Keiko , Matsuzaki Kei
Published: April 2003

The polymerization mechanism of 1,6‐anhydro‐2,3,4‐tri‐O‐benzyl‐β‐D‐glucopyranose (1) was investigated in order to synthesize 2,3,4‐tri‐O‐benzyl‐[1→6]‐α‐D‐glucopyranan (2a) and [1→6]‐α‐D‐glucopyranan (2b) (dextran) with high molecular weight. It was found that the optimum polymerization time to obtain high molecular weights was 40min when the monomer was polymerized in methylene chloride at −60°C. Stereoregular 2a with a \documentclass{article}\pagestyle{empty}\begin{document}$ \overline {DP} _{\rm n} $ of 1800 (M̄n = 777000), which was about twice as high as the highest \documentclass{article}\pagestyle{empty}\begin{document}$ \overline {DP} _{\rm n} $ previously reported, was obtained in 77% yield by polymerizing the monomer with 0.8 mole‐% PF5 as catalyst applying a monomer‐to‐solvent weight/volume ratio of 50%. 2a with a high molecular weight was debenzylated to give 2b with a \documentclass{article}\pagestyle{empty}\begin{document}$ \overline {DP} _{\rm n} $ of 446 (M̄n = 72300). The α‐stereospecificity and the solid state of the synthetic dextran were investigated by means of optical rotation, NMR spectroscopy, and X‐ray diffraction pattern.
Application of spin trapping technique to radical polymerization, 14. Initiation reaction of vinyl monomers with the tert‐butoxyl radical and evaluation of monomer reactivities
Authors: Sato Tsuneyuki , Otsu Takayuki
Published: April 2003

The initiation of various vinyl monomers with tert‐butoxyl radicals derived from the decomposition of di‐tert‐butyl peroxalate (DBPOX) was investigated by using the spin trapping technique with 2‐methyl‐2‐nitrosopropane (BNO), to detect and identify the intermediate radical species, and to evaluate the monomer reactivities toward the tert‐butoxyl radical. When the reaction of DBPOX with vinyl monomers, which have no α‐methyl group (CH2CH(X)), was carried out in the presence of BNO at room temperature, the propagating radical 1 ((H3C)3COCH2CHX) was trapped as its nitroxyl radical. However, in the cases of using α‐methylvinyl monomers (CH2CH(X)CH3), such as methyl methacrylate and methacrylonitrile, two kinds of radicals, 6 ((H3C)3COCH2C(X)(CH3), similar to 1) and 8 (CH2CH(X)CH2), were trapped as corresponding nitroxyl radicals. The coupling constants of the nitroxyls obtained from 1 and 6 were determined and discussed on the basis of their structure. When these reactions were performed in a reference solvent, p‐xylene, the above radicals, 1 (or 6) and/or 8, together with the p‐tolylmethyl radical (2), were trapped as their nitroxyls. From the ESR peak areas the relative reactivities of vinyl monomers toward the tert‐butoxyl radical were evaluated and found to depend not only on the polar nature, but also on the resonance effect of the substituents. In α‐methylvinyl monomers such as methyl methacrylate, the hydrogen‐abstraction from the α‐methyl group by the tert‐butoxyl radical was important.
Analysis of carbon‐13 nuclear magnetic resonance spectrum of polystyrene by means of model molecules
Authors: Jasse Bruno , Lauprêtre Françoise , Monnerie Lucien
Published: April 2003

The study of 2,4‐diphenylpentane (1), 2,4,6‐triphenylheptane (2) and 2,4,6,8‐tetraphenylnonane (3) by 13C NMR allows to compare the various chemical sequences of these compounds in terms of their chemical shifts.

Methyl, methylene and aromatic C1 carbons are particularly sensitive to tacticity. Moreover, from the aromatic C1 chemical shifts it is possible to propose an assignment of the corresponding pentads of polystyrene.
Dipole moments of poly(oxytetramethylene) and poly(oxydecamethylene) chains
Authors: Riande Evaristo
Published: April 2003

Dielectric constants have been determined for poly(oxytetramethylene) and poly(oxydecamethylene) chains in the thermodynamically good solvent benzene. The data for the former polymer indicate that the dipole moment ratio 〈μ2〉/(Nm2), is independent of the chain length as has been predicted for chains of such structural features. The value of this ratio for α‐hydro‐ω‐hydroxypoly(oxydecamethylene) chains is in the same range as that obtained for poly(oxyethylene), poly(oxytetramethylene) and poly(oxyhexamethylene) and is in fair agreement with that predicted by the isomeric state theory.
Studies on polymerizations initiated by syncatalytic systems based on aluminium organic compounds, 7. Reaction mechanisms
Authors: Magagnini Pier Luigi , Cesca Sebastiano , Giusti Paolo , Priola Aldo , Maina Marcello Di
Published: April 2003

The polymerizations of isobutene and its copolymerizations with isoprene by syncatalytic systems consisting of an aluminium compound R2AlX (with R = alkyl and X = alkyl or halogen) and of a halogen or an interhalogen compound are initiated by the addition of a positive halogen ion to the monomer. Chlorine is the best co‐initiator. Whereas in this syncatalyzed polymerization of isobutene the initiation is relatively slow and monomer transfer and termination are unimportant, in the polymerization of isobutene by AlCl3 or EtAlCl2 the initiation is very fast and there is at least one efficient termination. Our interpretation of these results includes a discussion of the different initiations and chain‐breaking reactions.

In the syncatalyzed polymerizations the initiation rate is governed by the relatively slow interaction of initiator and co‐initiator. Since the termination reactions are relatively unimportant, second and subsequent portions of monomer polymerize completely and faster than the first. The polymerizations initiated by AlCl3 or EtAlCl2 stop at incomplete conversion because of a termination which is chlorination of the carbenium ions by the anions; the AlCl3 thus formed is complexed by the unreacted monomer.
Phase changes of polyion complex between poly(methacrylic acid) and a polycation carrying charges in the chain backbone
Authors: Abe Koji , Ohno Hiroyuki , Tsuchida Eishun
Published: April 2003

The polyion complexes were obtained by mixing the aqueous solution of poly(methacrylic acid) and that of poly[(N,N,N′,N′‐tetramethyl‐N‐p‐xylylene)ethylenediammonium dichloride] (1). The forms of the polyion complex were observed as a homogeneous solution, a coacervate, or a precipitate under changing such conditions as the polyion concentration, pH, and the ionic strength. Especially, pH and the ionic strength affected the forms of the complex through the degree of dissociation of poly(methacrylic acid). The relations between these factors and the forms of the complex are shown as phase‐diagrams. The correlation among these factors is discussed, too.
Relation entre la solvatation préférentielle et la densité en segments de polymères de structure différente
Authors: Dondos Anastasios
Published: April 2003

This paper presents results on preferential solvation and viscosity in three ternary systems, (polystyrene (PS)‐benzene‐methanol, poly(2‐vinylpyridine)‐ethanol‐cyclohexane, and PS‐cyclohexane‐ethanol) using linear and branched polymers. It is shown that the representation ΔΛ′ (variation of the preferential solvation coefficient) as a function of ΔQ (variation of the segment density), gives curves which are not sensitive to branching and, therefore, caracteristic of the nature of the polymer and not of its structure. When there is an inversion in preferential solvation one can define “isosbestic” points, i.e. compositions of the solvent mixture for which Λ′ or ΔQ are independent of the molecular weight of the polymer.
The mean activity coefficient of cadmium polystyrenesulfonate
Authors: Vesnaver Gorazd , Špan Jože , Dolar Davorin
Published: April 2003

The electromotive force of the concentration cell with transference consisting of two identical cadmium amalgam electrodes and two solutions of cadmium polystyrenesulfonate with different concentrations, was measured for concentrations from 0,002 to 0,1 molal in monomer units. In the same concentration range transference and conductance measurements were performed in order to obtain the polyion transference number and the fraction of free counterions as functions of concentration. The logarithm of the mean activity coefficient derived from electromotive force and transference number is found to be a linear function of the logarithm of concentration. The experimental results are compared with the predictions of the cylindrical cell model and infinite line charge model. Satisfactory agreement between theory and experiment indicates that these models better represent the experimental results than the cube‐root relation which would follow from the ionic lattic structure of solution.
Synthesis and properties of co‐isotactic copolymers of functional vinyl aromatic monomers with chiral α‐olefins
Authors: Chiellini Emo , Carlini Carlo
Published: April 2003

Optically active co‐isotactic copolymers of α‐olefins, like (R)‐3,7‐dimethyl‐1‐octene (1) or (S)‐4‐methyl‐1‐hexene (2), with functional para‐substituted styrenes were obtained by both copolymerization in the presence of Ziegler‐Natta catalysts and by chemical modification of the copolymers of styrene (5) with 1 or 2. By the first mentioned route copolymers of 4‐iodostyrene (3) and propyl 4‐vinylbenzenesulfonate (4) were prepared in satisfying yields. Fractionation by solvent extraction as well as the physical properties of the polymeric products, guarantee for the formation of co‐isotactic copolymer macromolecules. By the other route co‐isotactic copolymers of 1 or 2 with several para‐substituted styrenes (like 4‐halo, 4‐chloromethyl, 4‐diphenylphosphino, 4‐diphenylphosphinomethyl, and 4‐alkylammoniomethyl chloride derivatives) were prepared under conditions which do not give appreciable racemization of the chiral centers present in the main chain as well as in the lateral chain of the starting copolymers of styrene with α‐olefins. The reported data provide a useful way to attain stereoregular and chiral macromolecular materials, bearing either electron donor or chemically active functional groups, inserted in a highly homogeneous conformational environment.
Spectroscopic measurements on spontaneously polymerizing styrene, 2. The estimation of the reactivity of the two Diels‐Alder‐isomers towards polymer radicals
Authors: Olaj Oskar Friedrich , Kauffmann Harald Friedrich , Breitenbach Johann Wolfgang
Published: April 2003

Spectroscopic measurements at 335 nm on polymerizing styrene have been carried out with spontaneously polymerizing as well as dibenzoyl peroxide (BPO)‐initiated bulk systems. The evidence for the formation of two Diels‐Alder‐intermediates, 1a and 1b, out of which only 1a seems to be capable to produce initiating radicals by reaction with the monomer, can also be derived from the development of the absorption, characteristic for the intermediates, during the BPO‐initiated polymerization. From the dependence of the overall rate constants of consumption of 1a, k2,a[M], and 1b, k2,b[M], on the rate of polymerization the reactivity of 1a and 1b towards polymer radicals can be estimated. Whereas 1b, the less reactive intermediate, seems to be mainly consumed by polymer radicals through copolymerization, chain transfer being unimportant, (the rate constant of consumption of 1b by polymer radicals, k3,b, relative to the constant of chain propagation kp ranges from 2,1 at 60°C to 3,2 at 80°C) the corresponding ratio for 1a, k3,a/kp, which goes from 113 at 80°C to 143 at 60°C, is supposed to represent primarily the constant of chain transfer of 1a in styrene polymerization. Under the condition of spontaneous polymerization the reaction with polymer radicals contributes 16% (for 1a) and 5–8,5%, depending on temperature (for 1b), to the overall rate of consumption of the intermediates. The stationary concentration of 1a, the isomer which accordingly is solely responsible for initiation as well as chain transfer in spontaneous styrene polymerization, is calculated to range from 5,2·10−6 mol l−1 at 60°C to 8,5·10−6 mol l−1 at 80°C.
Herstellung und antivirale Wirksamkeit von Polyacrylsäure und Polymethacrylsäure
Authors: Mück Karl‐Friedrich , Rolly Heinrich , Burg Karlheinz
Published: April 2003

The antiviral activity of a number of fractions of poly(acrylic acid)s and poly(methacrylic acid)s with different tacticities, different molecular weights and molecular weight distributions has been investigated. Isotactic poly(acrylic acid)s are essentially more antiviral active in the whole area of efficacy than the atactic ones. Independent of the tacticity poly(acrylic acid)s with molecular weights smaller than 5000 show no significant effects, polymers with molecular weights greater than 25000 are toxic in the used doses. The optimum of efficacy is between 6000 and 15000. Isotactic poly(acrylic acid)s with narrow molecular weight distributions are more active than those with broad distributions. The atactic poly(acrylic acid)s with lower efficacy do not show this relationship. Atactic poly(methacrylic acid)s are not antiviral active in vivo compared with untreated controls. Isotactic ones have a just detectable efficacy which is essentially lower than the activity of the atactic poly(acrylic acid)s.
Zur Bestimmung der Statistik der konstitutiven und konfigurativen Monomerverknüpfung in Polyolefinen durch NMR‐Spektroskopie
Authors: Elgert Karl‐Friedrich , Ritter Wolfgang
Published: April 2003

A simple statistical treatment of the constitutional and configurational monomer enchainment of substituted olefins for use in NMR spectroscopy is given.