bluuebunny/crossref_metadata_2025_split huggingface dataset:
MERRIFIELD‐synthese der insulinsequenz B 1–8 mit verschiedenen thiolschutzgruppen,
Authors: Hammerström Von Knut , Lunkenheimer Winfried , Zahn Helmut 
Published: April 2003

AbstractDurch die MERRIFIELD‐Synthese des Oktapeptid‐Derivats Phe‐Val‐Asn‐Gln‐His(Bzl)‐Leu‐Cys(R)‐Gly wurden die S‐Schutzgruppen R gleich Benzyl (Bzl), p‐Methoxybenzyl (Mbzl), Diphenylmethyl (Dpm), Trityl (Trt), Tetrahydropyranyl (Thp), Benzylthiomethyl (Btm), äthylcarbamoyl (Ec), Benzyloxycarbonyl (Z), Acetyl (Ac) und Benzoyl (Bz) auf ihre Brauchbarkeit bei Festphasen‐Synthesen geprüft. Der Bzl‐, Mbzl‐, Dpm‐, Btm‐ und Ec‐Rest haben alle Operationen gut überstanden, wurden aber außer der Bzl‐Gruppe zum Schluß mit HBr/Trifluoressigsäure zu einem geringen Teil abgelöst. Auch die Thp‐Gruppe war während der Synthese stabil, jedoch wurde sie durch HBr/Trifluoressigsäure völlig abgespalten. Nach Oxydation mit Luft und Gegenstromverteilung wurde mit hoher Ausbeute das Disulfid III erhalten. Die Oktapeptid‐Derivate mit dem Bzl‐, Mbzl‐, Dpm‐ und Btm‐Rest wurden mit Hilfe der Gegenstromverteilung rein dargestellt. Nach Deblockierung und nachfolgender Oxydation lieferten das Bzl‐, Mbzl‐ und Dpm‐Derivat das Disulfid II bzw. III in mäßiger bis geringer Ausbeute.
The polymerization, copolymerization and terpolymerization of 1‐isopropylidene‐3a.4.7.7a‐tetrahydroindene by anionic coordinate, radical and anionic catalysts
Authors: Cesca S. , Roggero A. , Salvatori T. , De Chirico A. , Santi G. 
Published: April 2003

AbstractBy means of vanadium based anionic coordinate catalysts 1‐isopropylidene‐3a.4.7.7a‐tetrahydroindene (I) can be terpolymerized with ethylene and propylene and copolymerized with ethylene. IR, NMR, UV spectroscopic data, and mol. wt. distributions are reported for the polymers.The incorporation of I is predominantly by opening of the cyclohexene double bond. The content of I was generally less than 10 mole‐%.Attempts to obtain homopolymers of I and copolymers of propylene and I with this type of catalyst were unsuccessfull.No solid polymer could be produced from I by free radical or anionic catalysts. With AIBN only oligomers were obtained which had cyanoisobutyric groups attached to the conjugated double bond system. K or KNH2 in ammonia solution react with I in equimolar ratios to give waxy products which do not contain NH2 groups. With K di‐hydrogenated derivatives of I are formed.The results have been interpreted in terms of stabilized radicals and anions derived from I which are unable to propagate.
The effects of ionizing radiation on the thermal properties of linear high polymers. Part 5. Ethylene/isotactic propylene block copolymer
Authors: Gee D. R. , Melia T. P. 
Published: April 2003

AbstractThe results of heat capacity measurements (over the temperature range 200–500°K) on an ethylene/isotactic propylene block copolymer (containing 12 mol‐% ethylene), which had been subjected to different doses of gamma radiation (0–1,000 Mrads) at 298°K, are described. After irradiation a single endotherm replaces the two observed with the unirradiated sample. The dependence of both the enthalpy and entropy of fusion on radiation dose is similar to that observed previously with isotactic polypropylene.
Investigations on polyethers containing nitro‐groups. I. The cationic copolymerization of glycidyl nitrate with other cyclic ethers
Authors: Abe Satsuki , Ito Mamoru , Namba Keiho 
Published: April 2003

AbstractCationic copolymerizations of glycidyl nitrate (GN) with some cyclic ethers were carried out to determine conditions under which glycidyl nitrate could be copolymerized with other ethers. Propylene oxide (PO), 3.3‐bis(chloromethyl) oxacyclobutane (BCMO), THF and trioxane (TO) were used as comonomers. In LEWIS acids, boron trifluoride complexes were the most active catalysts.The copolymerization parameters were estimated as follows: r1 = 0.03 and r2 = 1.85 for GN(M1)/PO(M2), r1 = 0.07 and r2 = 0.88 for GN(M1)/THF(M2) and r1 = 0.3 and r2 = 0.35 for GN(M1)/TO(M2) copolymerization.
Monte‐carlo‐rechnungen an makromolekülmodellen. 2. Mitt.: Quadratischer mittelwert des trägheitsradius und expansionskoeffizient
Authors: Bruns Von Wolfgang 
Published: April 2003

AbstractFür zwei gitterfreie Modelle wurden mit Hilfe der Monte‐Carlo‐Rechnung unter Berücksichtigung des „ausgeschlossenen Volumens”︁ Zufallsketten erzeugt, die als vereinfachtes Bild linearer Polymermoleküle dienen können. Die Ketten bestanden aus maximal etwa 100 Struktureinheiten. Die Abhängigkeit des mittleren Quadrats des Trägheitsradius von der Bindungszahl wurde bestimmt und dafür für n > 15 r̄2 = 0,229 n1,237 bzw. r̄2 = 0,185 n1,250 gefunden. Das Verhältnis h̄2/r̄2 nähert sich asymptotisch einem Wert von ca. 6,5. Sechs aus der Literatur bekannte Beziehungen zwischen dem Expansionskoeffizienten α und dem Wechselwirkungsparameter z wurden getestet. Für den untersuchten Bereich erwiesen sich die Näherung von FIXMAN, die allerdings modifiziert werden mußte, und die von JAMES als die besten. Letztere besitzt jedoch den Nachteil, daß ihre Anwendung für längere Ketten problematisch ist, während die Gleichung nach FIXMAN, wie Untersuchungen an Gittermodellen gezeigt haben, auch dort gültig ist. Die Größe des „ausgeschlossenen Volumens”︁ und des Verhältnisses von der Segmentzahl zur Zahl der Struktureinheiten wurde anhand der Ergebnisse diskutiert.
Production of organometallic polymers by the interfacial technique. XI. Synthesis of poly(organotin esters) and a study of some associated reaction variables
Authors: Carraher Charles E. , Dammeier Roger L. 
Published: April 2003

AbstractPolyesters of the form below are prepared by the interfacial method. Isolation procedures are presented and discussed.
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Polymer yield is constant as stirring rate, stirring time and nature of the organic solvent are varied. Molecular weight is constant as stirring rate and organic solvent nature are varied. Molecular weight increases as reaction time increases. No correlation is found between polymer molecular weight and polymer softening range.
Structure of poly‐1.3‐pentadiene prepared with lithium initiators
Authors: Inomata Jihei 
Published: April 2003

AbstractThe microstructure of poly‐1.3‐pentadiene prepared with lithium metal or lithiumalkyles in hydrocarbon solution has been studied by NMR spectroscopy (60 MHz and 100 MHz) and by IR spectroscopy. It was found that the chemical shifts (CHCl3 solution) of methyl protons in 1.4 units were δ(ppm) = 0.94 and 0.91, corresponding to cis and trans configurations of the double bonds in the polymer backbone, respectively, and that the chemical shifts of the methyl protons in 1.2 units were δ(ppm) = 1.66 and 1.60 corresponding to cis and trans configurations, respectively. As a result, the method of analysis for microstructure was established. Furthermore, the sequence of units in 1.4 structure of these polymers has been measured by IR studies on the hydrogenated polymers. According to this result, the ratio of the head‐to‐head/head‐to‐tail sequences among 1.4 units in poly‐1.3‐pentadiene was found to be 0.05 to 0.06.
Synthesis and conformational aspects of optically active oligo‐1‐methylethyleneurethans (L‐form) and oligo‐1‐benzylethyleneurethans (L‐form). Oligourethans. IX
Authors: Iwata Kaoru , Iwakura Yoshio 
Published: April 2003

AbstractOptically active oligo‐urethans

(R = methyl (L‐form), n = 1–7 and R = benzyl (L‐form), n = 2–4, respectively) were prepared by the stepwise method. The ORD of the oligomers obeyed the one‐term DRUDE equation in benzene, ethanol, and dioxane indicating that the oligomers form no helical conformation.
Free radicals in diene polymers induced by ultraviolet irradiation. I. An ESR study of cis‐1.4‐poly(isoprene)
Authors: Carstensen Peter 
Published: April 2003

AbstractTwo different samples of purified cis‐1.4‐poly(isoprene) were irradiated in vacuo at 77°K with ultraviolet light from a medium pressure mercury lamp. The free radicals formed by this irradiation were studied by electron spin resonance (ESR). The spectra obtained were interpreted as due to radicals formed by scission of the CC bonds midway between the double bonds. However, no radicals formed by hydrogen abstraction were observed. The radicals which contributed to the ESR spectra were:
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In addition the spectra contained a weak singlet interpreted as due to polyenyl radicals:
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with n equal to 3.The radical concentration was found to be dependent on the temperature. At liquid nitrogen temperatures all radicals were stable, but near the glass transition temperature the radical concentration decreased sharply.A sample of purified trans‐1.4‐poly(isoprene) showed after UV irradiation the same ESR spectra as cis‐1.4‐poly(isoprene), and was accordingly interpreted in the same way.The microstructural changes of poly(isoprene) caused by UV irradiation are discussed in relation to the identified radicals.
The polymerization of N‐vinylcarbazole by tetracyanoethylene
Authors: Nakamura Takahiro , Soma Mitsuyuki , Onishi Takaharu , Tamaru Kenzi 
Published: April 2003

AbstractKinetic and spectroscopic studies were carried out on the cationic polymerization of N‐vinylcarbazole (NVC) in the presence of tetracyanoethylene (TCNE) in benzene solution. On the basis of the experimental results the mechanism of this polymerization was discussed. It is concluded that the polymerization of NVC in the presence of TCNE proceeds through the formation of tetracyanocyclobutylcarbazole rather than that of a charge transfer complex.
The cationic polymerization of 1‐isopropylidene‐3a.4.7.7a‐tetrahydroindene
Authors: Cesca S. , Roggero A. , Palladino N. , Chirico A. De 
Published: April 2003

AbstractBy means of different cationic catalysts 1‐isopropylidene‐3a.4.7.7a‐tetrahydroindene (I) can be homopolymerized in a wide range of temperatures.Amorphous polymers having\documentclass{article}\pagestyle{empty}\begin{document}$$\overline {MW}$$\end{document}in the range 1,000–17,000 were obtained. IR, NMR, and UV data indicate the 1.4‐opening of the conjugated double bond system of (I). An α value of 0.68 in the KUHN‐MARK‐HOUWINKequation and the presence of two double bond for every repeating unit support the linear structure of the polymers obtained.The system Me3CCl/Et2AlCl was investigated. The co‐catalyst was consumed during the polymerization. The best yields were observed for values of the molar ratio Me3CCl/Et2AlCl ≥ 3. A strong alkylating ability of this catalyst toward toluene was found even at −78°C. No substantial structural differences were observed in the polymers obtained at different temperatures. Eapp= ‐3.23 kcal/mole was calculated from the log\documentclass{article}\pagestyle{empty}\begin{document}$$\overline {DP}$$\end{document}vs.1/T plot.Chlorine was found in the polymer; traces of aromatic rings were present when the polymerization was carried out in toluene; no hydroxyl groups were detected.The results obtained are discussed in terms of the nucleophilicity of (I) and of the pKavalues of the initial carbonium ions derived from (I).
Cationic polymerization of cyclic sulphides. I. Kinetic study of the polymerization of 3.3‐dimethylthietane initiated by triethyloxonium tetrafluoroborate
Authors: Goethals E. J. , Drijvers W. 
Published: April 2003

AbstractThe kinetics of the cationic polymerization of 3,3‐dimethylthietane with triethyloxonium tetrafluoroborate in methylene chloride at 20°C have been studied. The polymerization is characterized by a very fast initiation reaction. The propagation occurs most probably via cyclic sulphonium ions. The existence of a termination by reaction of the growing chains with sulphur atoms of the polymer chain was demonstrated by kinetic and molecular weight measurements. The propagation constants kp and termination constants kt at different temperatures were calculated.The enthalpies of activation for the propagation and termination reactions are, respectively, ΔH≠p = 12.5 kcal mole−1, ΔH≠t = 7.4 kcal mole−1, and the corresponding entropies of activation are ΔS≠p = ‐26 cal deg−1 mole−1, ΔS≠t = ‐49 cal deg−1 mole−1.
Polymerization of 2‐vinyl‐1.3‐dioxolane and 2‐methyl‐2‐vinyl‐1.3‐dioxolane
Authors: Madrid J. Martínez , Mateo J. L. 
Published: April 2003

AbstractThe polymerization of 2‐vinyl‐1.3‐dioxolane was examined with radical, anionic and cationic catalysts in the range from −80 to +40°C. The polymerization with radical initiators occurs exclusively through the vinyl double bond. With butyl lithium, a gas evolution takes place without polymer formation. The polymerization with BF3·OEt2 gave linear or cross‐linked polymers according to the type of solvent and polymerization temperature used. The runs giving soluble polymers are the result of vinyl‐vinyl addition (60–65%) and ring opening (35–40%); when ring opening takes place, 3–10% ester groups are formed due to hydride shift, while the remainder is produced by normal opening of the dioxolane cycle. Polymerization in acetone gave solid, linear polymers with a softening point of about 120°C.2‐Methyl‐2‐vinyl‐1.3‐dioxolane was synthesized and polymerized with radical, anionic and cationic catalysts. Unlike the dioxolane mentioned above the polymerization with BF3·OEt2 occurs at much slower rates, and all polymers obtained in homogeneous phase are soluble, independent of the solvent used. At the same time, the formation of ester groups has been observed. This fact seems to indicate the existence of an isomerization due to a shift of a methyl group.An explanation of the cleavage of the dioxolane ring in these derivatives with the substituent in position 2 is given.
Copolymères séquencés polyvinyl‐2 pyridine/polyvinyl‐4 pyridine: Synthèse, caractérisation et étude des phases mésomorphes
Authors: Grosius Par Paul , Gallot Yves , Skoulios Antoine 
Published: April 2003

AbstractOn a synthétisé à l'aide de la technique de polymérisation par voie anionique, des copolymères biséquencés polyvinyl‐2 pyridine/polyvinyl‐4 pyridine et polyvinyl‐4 pyridine/polyvinyl‐2 pyridine. On a opéré sous vide en milieu tétrahydrofuranne qui est un mauvais solvant, sinon un précipitant, de la polyvinyl‐4 pyridine; l'initiateur utilisé était le diphénylméthylsodium. On a montré que la copolymérisation est indépendante de l'ordre d'introduction des monomères dans le milieu réactionnel.Les échantillons ont été fractionnés par addition progressive d'heptane à leur solution dans un mélange tétrahydrofuranne/alcool méthylique. Les différentes fractions ont été caractérisées par diffusion de la lumière, osmométrie et analyse élémentaire. On a montré que les copolymères bruts ainsi préparés renfermaient très peu d'homopolymère et que les fractions recueilles avaient une polydispersité très faible, tant en masse qu'en composition.On a examiné par diffraction des rayons X aux petits angles de BRAGG, la structure des gels mésomorphes obtenus avec ces copolymères en présence soit d'octanol, solvant préférentiel des séquences polyvinyl‐4 pyridine, soit de tétrahydrofuranne, de dioxanne ou de benzène, solvants préférentiels des séquences polyvinyl‐2 pyridine. On a mis en évidence deux types de structure, l'une correspondant à un empilement périodique de feuillets, l'autre à un assemblage de cylindres selon un réseau héxagonal. On a déterminé la valeur des paramètres structuraux et on les a exprimés en fonction du degré de gonflement du gel.
Über die struktur der aus maleinsäureanhydrid in gegenwart organischer basen erhaltenen polymeren
Authors: Schopov Von Iwan 
Published: April 2003

AbstractUntersucht wird die Struktur der in Gegenwart von Triäthylamin und Pyridin aus Maleinsäureanhydrid anfallenden dunkel gefärbten Polymeren. Dem mit Triäthylamin erhaltenen Polymeren wird die Struktur von cis‐Polyvinylenketoanhydrid zugeordnet, ebenso dem in Gegenwart von Pyridin erhaltenen, dessen Kette jedoch auch andere Bausteine (Cyclopentanon, Maleinsäureanhydrid) enthält.Die Polymeren zeigen die Eigenschaften der polykonjugierten Polymeren: dunkle Farbe und Paramagnetismus; sie sind nur in polaren Lösungsmitteln löslich.
High pressure copolymerization of styrene with maleic anhydride
Authors: Enomoto Goichi , Ogo Yoshiaki , Imoto Tatsuya 
Published: April 2003

AbstractThe radical copolymerization of styrene with maleic anhydride was investigated in an acetone solution at 40°C under high pressure up to 4000 kg/cm2. Effects of pressure on the monomer reactivity ratio considering the influence of the penultimate monomer unit were studied from kinetic data and IR spectra. It has been found that the radical copolymerization rate increases with pressure, especially concerning the reaction of maleic anhydride with a polymer chain possessing a maleic anhydride unit preceding the active styrene chain end.
Oligomers of phenylpropiolonitrile and their chromatographic separation
Authors: Janić Milan , Beneš Milan J. , Peška Jan 
Published: April 2003

AbstractOligomeric products of the anionic polymerization of phenylpropiolonitrile were separated by elution chromatography on calcium hydroxide. The separation occurs not only according to the molecular weight, but mainly due to the cis‐trans‐isomerism. Four isomeric trimers were found among the isolated fractions, which demonstrated the polymerization to be non‐stereospecific.
Pyrolysis‐gas chromatographic investigation on structure of chlorinated 1.4‐polybutadienes
Authors: Ito Hajime , Tsuge Shin , Okumoto Tadaoki , Takeuchi Tsugio 
Published: April 2003

AbstractThermal degradation of chlorinated cis‐ and trans‐polybutadienes was studied by means of pyrolysis‐gas chromatography. The mechanism of chlorination reaction and thermal degradation of the polymers was examined over a wide range of degree of chlorination. The steric structure of so‐called head‐to‐head polyvinyl chloride was elucidated by analysis of such characteristic degradation products as o‐, m‐, and p‐dichlorobenzenes and vinylidenechloride.
Polykondensation von pyromellithsäuredianhydrid mit bisamidrazonen
Authors: Kersten Von Hilde , Meyer Gerhard 
Published: April 2003

AbstractDie Umsetzung von Pyromellithsäuredianhydrid mit Bisamidrazonen wurde untersucht. Es entstehen dabei unter Addition Polyacylamidrazoncarbonsäuren (A), die in zahlreichen organischen Lösungsmitteln löslich sind. Aus diesen Lösungen lassen sich z. B. Folien herstellen.Bei der thermischen Behandlung dieser Polymeren bilden sich unter Wasseraustritt zunächst Polyimidoamidine (B), die bei weiterem Erhitzen zu Polytriazolo‐iso‐indolonen (C) kondensieren. B und C sind in organischen Lösungsmitteln unlöslich und einige davon bis zu Temperaturen von 450–500°C stabil.
Die wechselwirkung der desoxyribonucleinsäure mit dem actinomin nach röntgenkleinwinkelmessungen
Authors: Wawra Von H. , Müller W. , Kratky O. 
Published: April 2003

AbstractEs wird die Wechselwirkung von Na‐DNS und Actinomin in verdünnten, wäßrigen NaCl‐Lösungen mit den Methoden der Röntgenkleinwinkelstreuung untersucht. Dafür mußten aus hochmolekularer DNS durch Ultraschallabbau Teilchen geeigneter Länge hergestellt werden, so daß neben dem Querschnitt auch die Teilchenlänge mit der Röntgenkleinwinkelstreuung noch zu erfassen war. Die Messungen erfolgten an mit Actinomin gesätigten DNS‐Lösungen bis herab zu einer DNS‐Konzentration von 0,045 g/100 ml. Es konnte dabei eine Streckung der abgebauten DNS‐Partikel bei Anlagerung von Actinomin um 18% festgestellt und die Menge des an die DNS gebundenen Actinomins bestimmt werden: im Mittel wird auf 7,1 Basenpaare ein Actinomin‐Molekül angelagert. Gleichzeitig wurde eine die DNS‐Partikel umgebende Hülle aus Gegen‐ und Bei‐Ionen durch Beugung festgestellt und deren räumliche Dimension ermittelt. Im Verlauf der Auswertung ist es auch gelungen, aus den vorliegenden Pseudo‐Querschnittsstreukurven die für unendlich lange Teilchen gültigen Querschnittsstreukurven‐Innenteile zu rekonstruieren.
Studies on maleate/fumarate isomerisation in unsaturated polyesters by infrared spectroscopy
Authors: Gupta S. K. , Thampy R. T. 
Published: April 2003

AbstractFor study of maleate/fumarate isomerisation in unsaturated polyesters infrared technique was used without using model compounds. This was done by solving the following equation for two different polyesters or one polyester with two concentrations for the molar extinction coefficients at 675 cm−1 for maleate and 980 cm−1 for fumarate.

equation image

Percentages of maleate and fumarate are given by following equations:

equation image

The out of plane vibration of CH for maleate appeared at slightly lower frequency, i.e. at 675 cm−1 due to steric hindrance. It was noted that the increase of the ratio of maleate to saturated acid in the polyester enhances the conversion from maleate to fumarate due to coiling tendency of the chain and causing steric compression. This tendency was also shown by phthalic anhydride based polyesters due to ortho carboxylic group compared with adipic acid and isophthalic acid. It is evident from more conversion from maleate to fumarate in case of phthalic anhydride based polyesters than that of isophthalic acid and adipic acid based polyesters.In case of bisphenol‐A based polyesters, low conversion from maleate to fumarate took place, because of less coiling of between the two segments of the chain which are phenyl groups associated through carboxyl group of maleate. Conversion was more pronounced in polyesters based on 2.2‐di‐(4‐hydroxy‐3.5‐dibromophenyl) propane and 2.2‐di‐(4‐hydroxy‐3.5‐dichlorophenyl)‐propane due to steric hindrance. An alternative explanation for more conversion from maleate to fumarate in case of halogenated bisphenol based polyesters may be due to catalysing effect of the small amount of halogen evolved during polycondensation. Similarly in chlorendic acid (1.4.5.6.7.7‐hexachloro‐5‐norbornene‐2.3‐dicarboxylic acid) based polyesters, the isomerisation from maleate to fumarate increases as the chlorendic acid content in the polyester increases. In this case catalysing effect of chlorine evolved during polycondensation may be more effective because dissociation of halogen from non‐aromatic system is easier than from aromatic system.
Determination of reactivity ratios for the copolymerisation of vinyl acetate with methyl acrylate by proton magnetic resonance spectroscopy
Authors: Kulkarni N. G. , Krishnamurti N. , Chatterjee P. C. , Sivasamban M. A. 
Published: April 2003

AbstractReactivity ratios for the copolymerisation of vinyl acetate with methyl acrylate have been determined in bulk at 60°C for conversions smaller than 1% using proton magnetic resonance spectroscopy. The values (rma = 6.3 ± 0.4; rva = 0.031 ± 0.006) thus obtained were compared with the values obtained by other workers using different analytical techniques. The present method appears to be extremely simple and accurate.
Polythiolester. I. Polythioglykolid
Authors: Elias Von Hans‐Georg , Bührer Heinrich G. 
Published: April 2003

AbstractThioglykolsäure‐S‐carbonsäureanhydrid wurde mit primären, sekundären oder tertiären Aminen, Natriummethylat, Wasser oder Natriumborhydrid als Initiatoren in Substanz oder in Tetrahydrofuran oder Dioxan gelöst bei Temperaturen zwischen −50 und +200°C zu Produkten mit Gewichtsmitteln Mw des Molekulargewichtes kleiner als 36000 g/mol Molekül und Schmelzpunkten von maximal 160°C polymerisiert. p‐Bromanilin, Thioglykolsäure und Borfluoridätherat initiierten die Polymerisation nicht. Nur Dichloressigsäure und Hexafluoraceton‐Sesquihydrat erwiesen sich als nichtabbauende Lösungsmittel. Säureamide und tertiäre Amine bauen die Polymeren ab. Der Polymerisationsmechanismus wird diskutiert. Die Polykondensation von Thioglykolsäure in Substanz führt unter Bildung ven Dithioglykolid als Nebenprodukt nur zu niedrigen Molekulargewichten. Thioglykolsäuremethylester zeigt mit verschiedenen Umesterungskatalysatoren etwa die gleiche Polykondensationsgeschwindigkeit wie Thioglykolsäure. Die Viskositäts‐Molekulargewichts‐Beziehung ergibt sich für Messungen in Dichloressigsäure bei 25°C im Molekulargewichtsbereich Mw = 5500 bis 36000 zu [η] = 0,018M ml/g.