bluuebunny/crossref_metadata_2025 huggingface dataset:
Changes of the polymerization mechanism depending on the monomer and solvent for a homogeneous Ziegler‐type initiating system
Authors: Barthelemy Pascal , Deffieux Alain , Sigwalt Pierre
Published: April 2003

The homogeneous system resulting from the reaction between tetrabenzylzirconium and triethylaluminium is an active catalyst for the polymerization of styrene, and p‐methyl‐, α‐methyl and p‐chlorostyrenes. The molecular weights and the structures of the resulting polymers are highly dependent on the nature of the monomer and on the reaction medium. In toluene, styrene and p‐methylstyrene give essentially linear unsaturated dimers, whereas p‐chlorostyrene leads to a polymer with a high molecular weight. In methylene dichloride higher oligomers and a polymer are obtained simultaneously from all the monomers. The comparative behaviour of the styrene derivatives was examined in copolymerization experiments under various experimental conditions. The ratios of monomer incorporation were compared with those reported in the literature for related systems. The results show that, according to the monomer and the reacting medium, the same catalytic system is able to induce polymerizations of the “coordinated anionic”, radical and cationic type.
Relaxation processes in a block copoly(ether‐ester) elastomer investigated by the spin probe method
Authors: Lembicz Franciszek , Ukielski Ryszard
Published: April 2003

Relaxation processes in the soft segment phase of a block copoly(ether‐ester) elastomer were investigated using the spin probe method. Rotational mobility of the two probes, differing in sizes, were analysed and the results were interpreted based on the relaxation diagram. It was found that the change in mobility of the probes, as detected by the change in ESR line shape, in the slow rotation region corresponds to the β‐relaxation, whereas that in the rapid rotation region corresponds to the α + β‐relaxation. The analysis of probe mobilities, including the way they rotate, indicates the necessity of inclusion of rotational anisotropy in the interpretation of the behaviour of probes of different size.
Cinétique de la diffusion de l'eau dans un film mince de photoresist
Authors: Sebillote Franc̨ois , Weill André , Paniez Patrick
Published: April 2003

Diffusion of water molecules in novolak‐based photoresist films commonly used in microelectronics is investigated. Thermogravimetry was used, in order to measure the diffusion constants of water molecules for temperatures ranging from 30 to 80°C. It is shown that the time to reach equilibrium with the surrounding atmosphere is only a few seconds for a dry 1 μm thick film of novolak‐based positive photoresist.
Asymmetric addition of hydrogen cyanide to aliphatic aldehydes catalyzed by a synthetic cyclic peptide, cyclo[(S)‐phenylalanyl‐(S)‐histidyl]
Authors: Asada Shoichi , Kobayashi Yoshiyuki , Inoue Shohei
Published: April 2003

The asymmetric addition of hydrogen cyanide to an aliphatic aldehyde, catalyzed by a synthetic dipeptide, cyclo[(S)‐phenylalanyl‐(S)‐histidyl] (1), leads to a product having a higher optical yield than that reported for the reaction using an enzyme (D‐oxynitrilase) as catalyst.
Reductions with the lithium aluminium hydride‐poly(N‐methylethyleneimine) complex suspended in hydrocarbon media
Authors: Tanaka Ryuichi , Kataoka Kazuya , Ueoka Isao , Saito Shogo
Published: April 2003

A variant of the reduction with lithium aluminium hydride (LAH), involving the complex of LAH with a high‐molecular‐weight, linear poly(N‐methylethyleneimine) (PMEI), is described. The reduction of simple aldehydes, ketones, or esters was found to proceed essentially within the solid LAH‐PMEI complex suspended in pentane and the resulting pure alcohols can be isolated by working up only the separated solid phase.
Polymerization of lactams, 74. Behaviour of the polymerization mixture prepared by the non‐activated polymerization of 2‐pyrrolidone above the limit polymerization temperature, 1
Authors: Fries Tomáš , Ciekerová Blanka , Roda Jan , Králíček Jaroslav
Published: April 2003

Polymerization mixtures of 2‐pyrrolidone, i.e. the mixtures of monomer, polymer and their potassium salts, prepared by non‐activated polymerization under optimal conditions (45°C), exhibit in the temperature interval between the ceiling temperature (70°C) and 110°C an increase in the polymer yield, whereas the yield and intrinsic viscosity [η] of the polymer decrease at higher temperatures (up to 160°C). The polymerization mixtures, heat stressed in this way, have an increased polymerization activity in comparison with the non‐activated polymerization, if exposed again to the optimal polymerization temperature. A controlling effect of the present semicrystalline poly(2‐pyrrolidone) and the stability of a part of growth centres, even at high temperature, are concluded from the investigated behaviour.
Acid curing of epoxy resins. A comparison between the polymerization of diepoxide‐diacid and monoepoxide‐cyclic anhydride systems
Authors: Matějka Libor , Pokorný Svatopluk , Dušek Karel
Published: April 2003

The molar masses of linear polyesters formed in the polymerization of stoichiometric mixtures of 1,7‐heptanedicarboxylic acid (4) with 2,2‐bis[4‐(2,3‐epoxypropoxy)phenyl]propane (2) (the diglycidyl ether of Bisphenol A), and of 1,2‐cyclohexanedicarboxylic anhydride (3) with 2,3‐epoxypropyl phenyl ether (1), catalyzed with tertiary amines, and the effect of the concentration of the tertiary amine catalysts were compared. In the reaction between anhydride 3 and epoxide 1 the molar mass of polyester, determined by GPC, was found to decrease with increasing concentration of the tertiary amine, whereas in the reaction of the acid it is independent of the catalyst content. The molar mass distribution is much narrower in the reaction of the anhydride. These results correspond to the mechanisms determined earlier: a stepwise mechanism in the reaction between epoxide and acid, and an “initiation” mechanism in the case of anhydride. In the polymerization of the dicarboxylic acid 4 with the diepoxide 2 good agreement was observed with the theoretical dependences, calculated by using the theory of branching processes.
Dégradation contrôlée des polyisoprènes‐1,4 par le couple phénylhydrazine/oxygène, 1. Etude sur molécules Modèles
Authors: de Barros Lobo Filho Eurico , Reyx Danièle , Campistron Irène , Casals Pierre‐François
Published: April 2003

Some constituents and structures in the mixtures obtained by reaction of oxygen with model compounds of 1,4‐polyisoprene in the presence of phenylhydrazine (1) could be identified. Accelerated oxidation of monomeric units 2 of 1,4‐polyisoprene by phenyl radical generation (reaction of 1 with oxygen) and in situ decomposition of hydroperoxides, allow to explain the formation of epoxidized and hydroxylated units which were identified. Identification of phenylsubstituted alcohols and phenyl ketones leads to the proposition of a chain cleavage process involving the addition of phenyl radicals to the double bonds of 2. No more carbonyl compounds or structures resulting from peroxide decompositions by carbon‐carbon bond cleavage could be detected. The hypothesis of their transformation into phenylhydrazones, followed by oxidation and decompositions, is supported by indications of phenylazo structures, but has to be confirmed.
13C NMR studies of the conformation of cyclic paraffins, n‐paraffins and polyethylene in solution
Authors: Yamanobe Takeshi , Sorita Tetsushi , Ando Isao , Sato Hisaya
Published: April 2003

High‐resolution 13C NMR spectra of cyclic paraffins, n‐paraffins and polyethylene were measured in 1,2,4‐trichlorobenzene solution, and the results were compared with the solid state 13C high resolution NMR data measured previously. It is proposed that in cyclic paraffins up to C32, the conformation in the solid state is retained even in solution, all the methylene carbons within the cyclic paraffin exhibiting identical gauche‐trans population with fast transition between the conformers in the ring plane, whereas in cyclic paraffins of larger carbon number, the conformation in the solid state is not retained in solution, the gauche‐trans populations being different in this case. The conformation of n‐paraffins and polyethylene is also discussed.
Structural study of compounds modelling elementary polymer units, 2. Molecular and crystal structures of bis[(3‐pentafluorophenoxy)phenyl] 4,4′‐oxydibenzoate and octafluorobiphenyl‐4,4′‐diylbis(oxy‐1,3‐phenylene) dibenzoate
Authors: Lindeman Sergey V. , Struchkov Yury T. , Malichenko Boris F. , Shklover Valerii E. , Vasnev Valerii A. , Kameneva Tatiana M. , Sheludko Evgenii V.
Published: April 2003

This paper discusses the synthesis and X‐ray studied of bis[(3‐pentafluorophenoxy)phenyl] 4,4′‐oxydibenzoate (10) and octafluorobiphenyl‐4,4′‐diylbis(oxy‐1,3‐phenylene) dibenzoate (11). These compounds are differently chosen models of the elementary unit of a polyarylate based on fluorinated bisphenols and aromatic dicarboxylic acids. Structures of 10 and 11 provide data on the conformational flexibility and the predominant was of arrangement of polyarylate chains.
Polymeric phthalocyanines and their precursors, 10. Thermal stability of polymeric phthalocyanines and their low molecular analogues
Authors: Wöhrle Dieter , Schulte Bernd
Published: April 2003

The thermal stabilities of structurally uniform polymeric phthalocyanines 2 and their lowmolecular‐weight model compounds 5 were examined. Thermal analyses under inert and oxidative conditions showed that the nature of the metal as well as that of the substituents and end groups has a decisive influence on the thermal stability. Polymers 2 turned out to be less stable as compared to their low‐molecular‐weight analogues 5. Generally, the stability under inert conditions was found to be higher than under oxidative conditions. For polymer 2b (Mt = Cu) it could be shown that 400°C must not be exceeded during its synthesis, whereas the polymer withstands isothermic temperatures of up to 500°C without decomposition.
Electroinitiated polymerization of p‐diethynylbenzene
Authors: Grovu‐Ivanoiu Maria , Bulacovschi Victor , Simionescu Cristofor I.
Published: April 2003

The electroinitiated anionic polymerization of p‐diethynylbenzene was carried out in various solvents with different solvation capacity using various electrolytes. The latter were classified depending on their efficiency for the polymerization which was found to be in good agreement with polarographic measurements. IR and H NMR spectral analyses of the polymers obtained showed the formation of extended π‐conjugated systems with only one of the two acetylenic bonds having reacted, thus giving soluble products suitable for structural studies.
Formation of the intermediate cyclic six‐membered oxonium ion in the cationic polymerization of β‐propiolactone initiated with CH3CO⊕SbF
Authors: Słomkowski Stanisław , Szymański Ryszard , Hofman Andrzej
Published: April 2003

Analysis of the 1H NMR spectra of \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^ \oplus {\rm OSbF}_{\rm 6}^ \ominus $\end{document} /β‐propiolactone and of the model systems \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^ \oplus {\rm OSbF}_{\rm 6}^ \ominus $\end{document}/(CH3)2O and \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm CH}_{\rm 3} \mathop {\rm C}\limits^ \oplus {\rm OSbF}_{\rm 6}^ \ominus $\end{document}/CH3COOCH3 in liquid SO2 in the temperature region −70 to −20°C revealed that the reaction of the acetylium cation with β‐propiolactone leads to the cyclic six‐membered oxonium ion 4, participating as an intermediate in the initial stage of polymerization.
Viscous properties of butadiene/styrene triblock copolymer solutions
Authors: Żuchowska Danuta , Meissner Wanda
Published: April 2003

Viscosities of dilute and concentrated solutions of a styrene‐butadiene‐styrene triblock copolymer in solvents of different thermodynamic quality and at different temperatures were studied. In 1,4‐dioxane (theta solvent for butadiene blocks) the viscosity derived polymer‐polymer interaction parameter has been found to be much smaller than in decalin (theta solvent for styrene blocks) or in tetralin (good solvent for both blocks). The dynamic viscosity and the enthalpy of activation of viscous flow, ΔH, increase much faster for 1,4‐dioxane solutions with increasing concentration than those for decalin or tetralin. The different properties of solutions in different solvents are discussed in terms of the physical structure of the systems.
Synthesis and characterization of polyamides deriving from 2,2′‐[sulfonylbis(1,4‐phenyleneoxy)]diacetic acid
Authors: Scariah Koonamparampil J. , Krishnamurthy Valadi N. , Rao Kalur V. C. , Srinivasan Mahalingam
Published: April 2003

Six semi‐aromatic polyamides (3a–f) were synthesized by low temperature solution polycondensation of aromatic diamines (1a–;f), containing flexible groups such as CH2, CH2CH2, O, S, and SO2, with 2,′2‐[sulfonylbis(1,4‐phenyleneoxy)]‐diacetyl chloride (2) in a solvent mixture of NMP and HMPT (vol. ratio 2 : 1). All the polyamides posses inherent viscosities in the range of 0,31 to 0,73 dl/g. They are soluble in polar amides and DMSO. The molecular weights, molecular weight distributions, thermal stabilities, thermal degradation kinetics and percentages of crystallinity were determined.
Formation of crosslinked polymers in the copolymerization of 9,10‐anthrylenedimethyl dimethacrylate and methyl methacrylate
Authors: Krakovyak Mark , Ananieva Tatiana , Anufrieva Elisaveta
Published: April 2003

The formation of a crosslinked polymer during the copolymerization of mono‐and bifunctional monomers was investigated choosing as an example the free‐radical copolymerization of methyl methacrylate (MMA) and 9,10‐anthrylenedimethyl dimethacrylate (1). The anthracenecontaining crosslinks permit the determination of the topological structure of soluble MMA‐1 copolymers containing bridge bonds. This copolymer is formed first and characterized by a considerable structural heterogeneity. The intrinsic viscosity of the soluble copolymer increases sharply in a certain reaction stage and, at the same time, an insoluble copolymer fraction appears. In the formation of the gel fraction those branched macromolecules which consist of a greater number of linear components and contain a greater number of “pendent” double bonds participate first.
Chain folding in oligo(oxyethylene)s. A study of the C1, C10, C13, C15, C18 and C21 dialkyl ethers of pentatetracontaethylene glycol
Authors: Yeates Stephen G. , Booth Colin
Published: April 2003

Oligomers of general formulaH(CH2)n(OCH2CH2)45O(CH2)nH, with n in the range 1 to 21, were prepared. Both the oxyethylene and the alkyl blocks are homogeneous. It was shown (by X‐ray scattering, IR spectroscopy and differential scanning calorimetry) that annealed crystalline samples have structures in which the oxyethylene blocks are normal to their end‐group planes and are either once‐folded (n = 18, 21) or unfolded (n = 10, 13, 15). It was also shown that rapidly crystallised samples with n = 10, 13, 15 and 18 have long spacings (by SAXS) intermediate in value between those of the unfolded and once‐folded forms.
Synthesis and polymerization of N‐acryloyl‐ and N‐methacryloylaminomethyl crown ethers
Authors: Nakatsuji Yohji , Furuyoshi Shigeo , Okahara Mitsuo , Takemoto Kiichi
Published: April 2003

Polymerizable crown ethers, N‐acryloyl‐ and N‐methacryloyl‐N‐ethylaminomethyl crown ethers (4a,b and 5a, b), were prepared from N‐ethylaminomethyl crown ethers (1 and 2). Their polymerization and copolymerization with styrene afforded the new poly(crown ether)s (6), in which the crown rings are attached to the polymer chain by an amide linkage.
Functional polymers and sequential copolymers by phase transfer catalysis, 20. Synthesis of copolymers and alternating block copolymers containing thermotropic liquid crystalline polyethers and aromatic poly(ether sulfone) segments
Authors: Shaffer Timothy D. , Percec Virgil
Published: April 2003

Copolymers and alternating block copolymers were prepared both containing a liquid crystalline (LC) polyether segment, based on 4,4′‐biphenyldiol (3) and 1,5‐dibromopentane (2), and a thermoplastic segment, deriving from an aromatic poly(ether sulfone) (PSU) (1). The alternating block copolymer was prepared by the phase transfer catalyzed (PTC) polyetherification of mesogenic α,ω‐bis(5‐bromopentoxy)polyether (5) with α,ω‐bis(hydroxyphenyl)PSU (1). Copolymers containing mesogenic segments were prepared utilizing α,ω‐bis(hydroxyphenyl)‐PSU as another diphenol in the PTC polyetherification of 5 with 2 and 3. The thermal behavior, as characterized by differential scanning calorimetry (DSC), revealed phase separation for all prepared copolymers as well as liquid crystalline behavior down to a content of mesogenic units deriving from 5 as low as 30 wt.‐%. Optical polarization microscopy, however, revealed significant differences in textures of the copolymers with the textures observed for homopolymer 5. Textures of a 5/PSU blend clearly show phase separation.
Lichtinitiierte polymer‐ und polymerisationsreaktionen, 26. Elektrophile ringöffnungsreaktionen zwischen glycidylethern und ketonen oder aldehyden initiiert durch photoinitiatorsysteme
Authors: Timpe Hans‐Joachim , Merckel Carsten , Baumann Harald
Published: April 2003

By the irradiation of benzoin derivatives in the presence of arene diazonium salts or aryl iodonium salts cationic species are formed, which initiate ring‐opening reactions of 2,3‐epoxy‐propyl (glycidyl) ethers in the presence of ketones or aldehydes. 1,3‐Dioxolane formation dominates over homopolyaddition reactions of glycidyl ethers. This method forms dioxolane in satisfactory preparative yields. The quantum yields of disappearance of phenyl glycidyl ether in acetone (ΦPGE) were measured in dependence of some system parameters. By the photolysis of benzil dimethyl ketal more catalytic species are produced as in the case of benzoin isopropyl ether or α‐phenylbenzoin. The ΦPGE values for diazonium salts are higher than for iodonium salts, with triphenylsulfonium salts the reaction failed. With the anions of iodonium salts the following sequence for ΦPGE is observed: SbF6− > PF6− ≫ SbCl6− = BF4− = 0. Because the key step of the catalyst formation is an electron transfer reaction between radicals produced by the photolysis and the onium ions, the concentration of the salts influences ΦPGE. Phenyl glycidyl ether reacts more rapidly than 2,2‐bis(4‐hydroxyphenyl)trimethylene diglycidyl ether and isobutyl glycidyl ether.
Polymeric phospholipid analogues, 19. Synthesis and polymerization of 10‐(11‐methacryloyloxyundecyloxycarbonyl)decyl 2‐(trimethylammonio)ethyl phosphate
Authors: Furukawa Akio , Nakaya Tadao , Imoto Minoru
Published: April 2003

10‐(11‐Methacryloyloxyundecyloxycarbonyl)decyl 2‐(trimethylammonio)ethyl phosphate was prepared, characterized, and polymerized with 2,2′‐azoisobutyronitrile (AIBN). The polymer exhibits liquid crystalline behaviour from room temperature up to ca. 280°C and is soluble in methanol and hot ethanol.
Complexation of alkali‐ and alkaline‐earth cations by poly(oxyethylene)s in methanol
Authors: Buschmann Hans‐Jürgen
Published: April 2003

Stability constants and thermodynamic values for the reaction of alkali and alkaline‐earth cations with poly(oxyethylene)s in methanol were measured by means of calorimetric titration. The apparent molecular weights of the ligands were determined by means of calorimetric end point titration. This method gives direct information on the composition of the complex formed in solution. The measured stability constants for a given ligand with K+, Rb+, Cs+, and Ba2+ ions are all of the same order of magnitude. Poly(oxyethylene)s with high molecular weight are able to surround cations completely. The reaction enthalpies for the reaction with poly(oxyethylene)s reach higher values as compared to crown ethers. From these data, the bond energies between a complexed cation and a single donor atom of the ligand were calculated for the first time.
New amphipathic lipopeptides, 1. Synthesis and mesomorphic structures of lipopeptides with polysarcosine peptidic chains
Authors: Douy André , Gallot Bernard
Published: April 2003

Amphipathic lipopeptides CnSarp with a hydrophobic aliphatic chain, Cn, and a hydrophilic peptidic chain of polysarcosine, Sarp, were synthesized by two methods, a step‐by‐step method and a polymerization method. In the step‐by‐step method, the sarcosine residues are added one by one at the end of a fatty amine (n‐alkylamine, n = 12,14,16,17,18). In the polymerization method, sarcosine N‐carboxyanhydride is polymerized initiated by the amino end of a fatty amine. In concentrated water solution, lipopeptides CnSarp exhibit mesophases whose structure was determined by means of X‐ray diffraction. Three types of mesomorphic structures (lamellar, cylindrical hexagonal, and body‐centred cubic) and two types of polymorphism (one as a function of the length of the peptidic chains, the other as a function of the water content of the mesophases) were established. Furthermore, the respective influence of the factors, governing the type of structure of the mesophases and the values of their geometrical parameters, were analysed.
Metal salt catalysed transesterifications of thioesters and their application to polyester syntheses
Authors: Sasakawa Tomoyoshi , Takasaki Haruhiko , Ikeda Tomiki , Tazuke Shigeo
Published: April 2003

The transesterification of S‐phenyl thiobenzoate with 1‐butanol, catalysed with metal salts, was studied as a model reaction for the polyester synthesis. The metal salts were found to interact with both the alcohol and the thioester. Mn(OCOCH3)2 · 4H2O, the most active catalyst, shows a higher kinetic order as well as a greater temperature dependence than the less active catalyst LiOCOCH3 · 2H2O, whereas the uncatalysed reaction shows the smallest temperature dependence. The application of the catalysts for polyester formation was examined with S,S‐diphenyl 1,4‐benzenedicarbothioate and triethyleneglycol. The molecular weight of the resulting polyester was found to increase with increasing catalytic activity of the metal salt in the corresponding monofunctional model reaction.
Anionic polymerization of fluorine‐containing vinyl monomers, 5. Polymerization of fluoroalkyl acrylates and methacrylates with delocalized carbanionic initiators
Authors: Narita Tadashi , Hagiwara Tokio , Hamana Hiroshi , Yanagisawa Hayato , Akazawa Yoshimi
Published: April 2003

Anionic polymerizations of 2,2,2‐trifluoroethyl acrylate (1a), 2,2,2‐trifluoroethyl methacrylate (1b), 2,2,2‐trifluoro‐1‐trifluoromethylethyl acrylate (2a), and 2,2,2‐trifluoro‐1‐trifluoromethylethyl methacrylate (2b) showing low reactivity toward alkyllithium and alkylmagnesium compounds, were examined with several delocalized anionic initiators. 1,1‐Diphenylhexyllithium, disodium salt of living α‐methylstyrene oligomer, and sodium dihydronaphthylide were found to yield the corresponding polymers of 1b and 2b with appreciably high conversions. On the contrary, no polymerization conditions were found to produce polymers of 1a and 2a. The polymerization reactions follow an anionic addition polymerization mechanism, according to the results of 1H NMR and GPC measurements.
A new chain transfer reaction in the anionic polymerization of 2,3‐epoxypropyl phenyl ether and other oxiranes
Authors: Stolarzewicz Andrzej
Published: April 2003

Carbonyl groups were found to be present in polymers of 2,3‐epoxypropyl phenyl ether obtained by anionic polymerization. On the basis of quantitative analyses these groups were assumed to be formed in a reaction involving chain transfer to the monomer which proceeds in a manner different from that reported in the literature. Results of the present study were compared with those referring to the polymerization of methyloxirane, phenyloxirane and some chlorophenyl 2,3‐epoxypropyl ethers.
Polylactones, 7. The mechanism of cationic polymerization of β‐propiolactone and ϵ‐caprolactone
Authors: Kricheldorf Hans R. , Jonté J. Michael , Dunsing Ruth
Published: April 2003

Homopolymerisations of β‐propiolactone and ϵ‐caprolactone, initiated by means of methyl trifluorosulfonate, triethyloxonium tetrafluoroborate or acetylium perchlorate, were investigated. Both 1H and 13C NMR spectra proved that the alkylating initiators yield polyesters with alkyl ester end groups, indicating a chain growth via alkyl‐oxygen cleavage of the lactone. At temperatures below 100°C cationic polymerizations initiated by alkylating reagents were found to proceed via end groups which may cause degradation due to back‐biting. When ϵ‐caprolactone was reacted with excess methyl triflate, high concentration of triflate ester end groups were formed, whereas in the case of β‐propiolactone active end groups were not detectable by 1H NMR spectroscopy. Initiation with acetylium perchlorate yielded a polyester with acetate end groups. Acetate end groups were also obtained, when “living” polymers, initiated with methyl triflate, were reacted with acetic anhydride. It could be shown that the formation of acetate end groups does not indicate an electrophilic attack at the endocyclic oxygen. Furthermore, it is discussed that any experimental evidence for a cationic chain growth via acyloxygen bond cleavage is lacking.
Cyclopolymerization, 12. Mechanism of free‐radical cyclopolymerization of acryloyl‐ and methacryloylmethylallylamines
Authors: Kodaira Toshiyuki , Sumiya Yoshinori
Published: April 2003

Cyclopolymerizability of acryloylmethylallylamine (1b) was investigated and compared with that of methacryloylmethylallylamine (1a) which is known to yield a highly cyclized polymer with a small amount of pendant methacryloyl groups. The structural study of poly(1b) revealed that residual unsaturation consists exclusively of allyl groups and the degree of cyclization is very low. ESR measurements on the 1b polymerization system yielded only the acryloyl radical as propagating radical. Thus, 1b is incorporated into the polymer mainly through its acryloyl group and the rate‐determining step in the cyclopolymerization process of 1b is intramolecular cyclization. On the other hand, the ESR spectrum of 1a consists of cyclized and uncyclized radicals. In this case intramolecular cyclization does not proceed much faster than intermolecular propagation of the cyclized radical. ESR further revealed that the polymerization of 1a first involves the allyl group and then intramolecular cyclization occurs. The difference in cyclopolymerizabilities between 1a and 1b may be interpreted on the basis of the hypothesis that the lower the polymerizabilities of the monofunctional counterparts of unconjugated dienes, the higher their cyclopolymerizabilities.
Comparison of different polymolecularity correction formulae for the burchard‐stockmayer‐fixman relationship
Authors: Bareiss Rolf E.
Published: April 2003

Polymolecularity correction of the original and the modified procedure according to Burchard, Stockmayer and Fixman, especially useful for the determination of the unperturbed dimensions of macromolecules, is derived via the general “principle of corresponding averages” and compared with the polymolecularity correction methods published by Sutter et al. and Rosenvasser et al. It is shown that the polymolecularity correction factor to be used with the mass‐average molar mass in the Burchard‐Stockmayer‐Fixman relationship is identical to that derived from the corresponding averages of this relationship. Numerical calculations with series of hypothetical monomolecular and polymolecular (exhibiting Schulz‐Zimm distributions of the molar mass) polymer‐homologous polymer samples in three different thermodynamically good solvents also demonstrate the superiority of the correction method according to Sutter et al. as compared to the correction method of Rosenvasser et al.
Studies on chitosan‐induced metachromasy, 4. Some correlations between dye structure and metachromatic behaviour
Authors: Gummow Beryl D. , Roberts George A. F.
Published: April 2003

The induction of metachromasy in 36 anionic dyes by addition of chitosan and in 4 cationic dyes by addition of sodium carboxymethylcellulose, was examined. The results show that metachromasy is exhibited by dyes having localised ionic charges as well as those in which the charge on the dye ion is delocalised over the chromophoric system, and by dyes containing more than one ionic group. Both bathochromic and hypsochromic shifts in λmax were found and the direction of shift correlated with the general structure of the dye and interpreted in terms of the probable arrangement of the dye ions in the dye aggregates.
Interaction of 14CO with Ziegler‐type heterogeneous catalysts and effect of interaction products on the determination of the amount of active centers
Authors: Bukatov Gennadii D. , Goncharov Valerii S. , Zakharov Vladimir A.
Published: April 2003

The interaction of 14CO with Ziegler‐type heterogeneous catalysts (titanium‐magnesium catalysts, titanium trichloride) in the absence of an olefin was studied. This reaction was found to produce radioactive products soluble in hexane. Formation of such products takes place in the presence of both titanium chloride and AlR3, and is attributed to the insertion of 14CO into the Ti‐R bonds. For titanium‐magnesium catalysts the number of labels in hexane may exceed the number of titanium atoms in the catalysts, which indicates that the Ti‐R bond may be regenerated by AlR3. In the starting phase labelled products are formed at maximum rate, which is an evidence that a rapid insertion of 14CO (some minutes) into Ti‐R bonds takes place. The effect of side labelled products on polypropylene radioactivity is examined and the necessity to purify the polymers from radioactive impurities is shown. The influence of the side process of the interaction of 14CO with the catalytic system on the determination of the amount of active centers is discussed.
Polymerization of propene in the presence of MgCl2‐supported Ziegler‐Natta catalysts, 3. Catalyst deactivation
Authors: Busico Vincenzo , Corradini Paolo , Ferraro Angelo , Proto Antonio
Published: April 2003

The different trends of polymerization rate as a function of time observed when polymerizing propene, ethylene and mixtures thereof in the presence of MgCl2‐supported catalysts are explained assuming that catalyst deactivation is due to the reduction of Ti (III) by alkylaluminium to lower, polymerization‐inactive oxidation states, and that ethyene polymerization is diffusion‐controlled. A possible route for Ti reduction is also presented, which might give the reason for the observed kinetics of polymerization rate decay.
Preparation and polymerization of 2‐chloroethyl 2‐(methacryloyloxy)ethyl hydrogen phosphate and 2‐bromoethyl 2‐(methacryloyloxy)ethyl hydrogen phosphate
Authors: Nakaya Tadao , Toyoda Hirokazu , Imoto Minoru
Published: April 2003

2‐Chloroethyl 2‐(methacryloyloxy)ethyl hydrogen phosphate (5a) and 2‐bromoethyl 2‐(methacryloyloxy)ethyl hydrogen phosphate (5b) were synthesized, characterized, and polymerized with 2,2′‐azoisobutyronitrile (AIBN). In the polymerization of 5a in DMF with AIBN, the rate of polymerization was found to be proportional to [AlBN]0,54 and to [5a]1,54. The over‐all activation energy for the polymerization of 5a was estimated as 59,5 kJ · mol‐1. From the radical copolymerization of 5a with styrene in DMF at 60°C, Q and e values for 5a were evaluated as Q = 2,65 and e = 0,53.
Molecular relaxations in poly(ethylene adipate) and block urethane elastomers as studied by the spin probe method
Authors: Lembicz Franciszek , Kuriata Jerzy , Słonecki Jerzy
Published: April 2003

The spin‐probe method is used to study the rotational mobility of two different probes in poly(ethylene adipate) and a block urethane elastomer synthetized using poly(ethylene adipate), 4,4′‐methylenebis(phenyl isocyanate) and 1,4‐butanediol. The observed ESR spectra correspond to slow and rapid rotations of spin probe molecules. They are interpreted using both the isotropic and anisotropic models for the spin probe motion. It is found that at low temperatures the behaviour of spin probes is related to the β‐relaxation, whereas at higher temperatures to the α + β‐relaxation. Differences in mobilities are probably connected with different sizes of spin probes used.
Fixation d'anticorps par liaisons covalentes sur le polystyrène. Activation du support et utilisation répétée du système polystyrène anticorps après test immunoenzymatique
Authors: Couturier Roger , Ville Albert , Perrin Bernard , Favre‐Bonvin Guy
Published: April 2003

Antibodies were immobilized by covalent linkage on polystyrene balls for use in solid phase enzyme‐linked immunoassays: application for detection of K 99+ E. Coli in calves. The method eliminates the problem of antibody desorption noted in coventional enzyme‐linked immunosorbent assays which are based on simple adsorption on polystyrene. Further, the bond between antibodies and polystyrene balls is stable under conditions under which usually antibody — antigen complexes dissociate and permit re‐use of the immobilized antibodies for immunoassay.
Influence of hydrogen bonding on the properties of elastomers and elastomeric blends
Authors: Stadler Reimund , Burgert Josef
Published: April 2003

Polybutadienes and polyisoprene are modified using 4‐phenyl‐1,2,4‐triazoline‐3,5‐dione. The resulting urazole moieties give rise to the formation of hydrogen bonds. From the temperature dependence of the dilute solution viscosity as well as from GPC it can be deduced that intra‐ and intermolecular hydrogen bonds are formed. The intermolecular hydrogen bonds can be used to overcome the demixing tendency in blends of polybutadiene and polyisoprene. DSC measurements indicate enhanced miscibility depending on the degree of modification.
Viscosity of aqueous and alkaline solutions of poly(ethylene oxide)
Authors: Gregory Peter , Huglin Malcolm B.
Published: April 2003

Viscosity measurements over a wide range of temperature were made on aqueous solutions of poly(ethylene oxide) samples of different molar mass and of low polydispersity. Above ca. 308 K the Mark‐Houwink exponent decreases and tends to a value of 0,50 at a lower critical solution temperature of 376 ± 2 K. The same value for this θ‐temperature is derived also as that at which the slope of Stockmayer‐Fixman plots tends to zero. At 298 K the unperturbed dimensions [〈r2〉0/M]1/2 = 0,089 nm · g−1/2 · mol1/2 and their temperature coefficient d ln 〈r2〉0/dT ≈ − 1,5 (±0,5) · 10−3 K−1. In aq. KOH the intrinsic viscosity [η] is virtually uninfluenced by pH at low‐medium pH, but at high pH, [η] falls sharply. Viscosity and phase separation measurements yield θ‐conditions in 1,24 M aq. KOH at 298 K. The derived polymer‐water interaction parameters χ increase from 0,449 at 276 K to 0,493 at 358 K, but the enthaplic component χH is incapable of yielding a meaningful value for the solubility parameter δ2 of the polymer in such a hydrogen‐bonding system. The calculated value of χ2 was 18,9 (kJ · dm−3)1/2.
Kinetics of radical polymerization of methyl methacrylate initiated with dimethyl 2,2′‐azodiisobutyrate
Authors: Stickler Manfred
Published: April 2003

The kinetics of free‐radical bulk polymerization of methyl methacrylate with dimethyl 2,2′‐azodiisobutyrate as an initiator was investigated at 40, 60, and 80°C. Non‐ideal polymerization behaviour was observed when the initiator concentration was varied by a factor of more than one thousand. This departure from classical polymerization kinetics is discussed in terms of primary radical termination and a chain length dependent termination rate constant, with the structural similarity of both primary and polymeric radicals facilitating the treatment very much. The kinetic analysis indicates that in the polymerization of methyl methacrylate the termination rate constant is a function of the degree of polymerization of the involved macroradicals.
Coordination polymers of N,N′‐bis(8‐hydroxy‐5‐quinolinyl)‐terephthalamide
Authors: Patel Ravji D.
Published: April 2003

Fe(II), Co(II), Ni(II), Cu(II) and Zn(II) complexes of the bisbidentate ligand N,N′‐bis(8‐hydroxy‐5‐quinolinyl)terephthalamide (1) were synthesized. All the metal complexes are characterized by elemental analyses, infrared spectra, electronic reflectance spectra, magnetic susceptibility measurements and thermogravimetry. All the complexes showed a polymeric nature with a octahedral stereochemistry at the coordinated metal atom. The fungicidal screening of the coordination polymers showed them to be antifungal against Penicillium islandicum, Rizopus nigricans and Botrydiplodia theobromae.
Polymorphism and crystal structures of trans‐1,4‐polyisoprene. An analysis by conformational and packing energy calculations
Authors: Napolitano Roberto , Pirozzi Beniamino
Published: April 2003

The polymorphism of trans‐1,4‐polyisoprene is discussed on the basis of conformational and packing energy calculations. These calculations suggest chain conformation and mode of packing for the α and β modifications. Two other chain conformations with a c axis near to that of the α modification are energetically accessible.
Emulsion copolymerization of methyl methacrylate with ethyl acrylate, 1. Effect of the initiator concentration on the polymerization behaviour
Authors: Capek Ignác , Tuan Le Quang
Published: April 2003

The emulsion copolymerization of methyl methacrylate with ethyl acrylate, initiated by ammonium persulfate in the presence of both anionic and nonionic emulsifiers, was kinetically investigated at 60°C by the conventional gravimetric method. In the range of low conversions the rate of polymerization was found to be proportional to the 0,5 power of the initiator concentration. Over the range of medium conversions the rate of polymerization is approximately proportional to the 0,35 power of the initiator concentration and the number‐average molecular weight is inversely proportional to the 0,4 power of the initiator concentration. The molecular weight increases up to 30% conversion and then it remains constant up to the total monomer consumption. It was found that the mean particle diameter decreases while the number of particles per volume unit, the conductivity of final latices, the coagulate yield and the number of radicals per particle increase with increasing concentration of the initiator.
Smectic behaviour of linear random copolymers containing the stilbene‐4,4′‐dicarboxy group
Authors: Carfagna Cosimo , Roviello Antonio , Santagata Salvatore , Sirigu Augusto
Published: April 2003

Copolymeric systems of the general formula: P1 = {((OCH2CH2)aOR)m ((OCH2CH2)bOR)n}x or P2 = {((OCH2CH2)aOR)m (O(CH2)bOR)n}x with R = OCC6H4CHHCC6H4CO were prepared and their mesophasic properties studied by polarizing microscopy, differential scanning calorimetry and X‐ray diffraction analysis. Enantiotropic smectic mesomorphism was directly observed in most cases. For all systems but P2(a = 2, b = 12) a single smectic phase was observed for all compositions, with a continuous variation of the smectic structural periodicity, isotropization temperatures and molar entropic changes close to the weighted average. This indicates a complete compatibility of the different monomer units in the formation of the smectic layers. On the contrary, system P2 (a = 2, b = 12) exhibits two smectic phases each within a definite range of composition. The two phases are sharply distinct as far as the structural periodicity is concerned. Both phases are present in the mesophasic state of copolymer with m = 75.
Molar mass dependence of rate constants for random scissions of macromolecules
Authors: Elias Hans‐Georg
Published: April 2003

Reported initial rate constants of the hydrolyses of oligomers and polymers of cellulose and glycine are shown to depend linearly on the inverse of the initial number of cleavable bonds. The slope of this function may be interpreted by many different assumptions on ultimate, penultimate, etc. effects.
Relationship between elastic modulus and volume swelling degree of polymer networks swollen to equilibrium in good diluents, 4. Interpretation of experimental results on the basis of scaling concepts
Authors: Hild Gérard , Okasha Rouzi , Macret Michel , Gnanou Yves
Published: April 2003

The results displayed in the present paper deal with the scaling behaviour of various polymer networks swollen at equilibrium in good diluents. The scaling law, established by de Gennes, between the elastic modulus and the equilibrium segment concentration was tested using polystyrene networks, poly(ethylene oxide) networks, and poly(2,3‐dihydroxypropyl methacrylate) networks. The experimental exponents s obtained are generally in agreement with the expected theoretical value (s = 2,25), especially for networks obtained at high conversion degrees whatever the nature of the polymer or the type of gelation. At incomplete conversions, the sol‐fraction is important and the defects are numerous; in this case discrepancies are observed between the theoretical and experimental exponents.
Etude structurale des télomères du méthacrylate d'époxy‐2,3 propyle avec les thiols
Authors: Bessière Jean‐Marie , Boutevin Bernard , Snoussi Mohamed‐Hichem , Taha Mohamed
Published: April 2003

The structure of telomers 5a, b, prepared from 2,3‐epoxypropyl methacrylate (2) and benzenethiol (1a) or 1‐dodecanethiol (1b) by UV irradiation, was studied by MS, IR, 1H and 13C NMR spectroscopy. The IR spectra of the products show that thiol addition occurs only at the double bond of monomer 2. Mono‐ and diadducts could be isolated by fractionation and were characterized spectroscopically together with higher telomers (10 < DPn < 200). Coupling constants and chemical shifts were assigned for the mono‐ and diadducts unambiguously. The tacticity of higher telomers was determined and found to follow the Bernoulli statistics.
Group transfer polymerization of methacrylonitrile
Authors: Bandermann Friedhelm , Witkowski Reiner
Published: April 2003

The group transfer polymerization of methacrylonitrile in acetonitrile, initiated by 2‐(trimethylsilyl)isobutyronitrile in presence of tetraethylammonium cyanide or tetrabutylammonium fluoride as coinitiator, is accompanied by an anionic polymerization initiated by the coinitiator alone so that polymers with bimodal molecular weight distributions are formed. In contrast, with tris(dimethylamino)sulfonium difluorotrimethylsilicate as coinitiator a pure GTP is observed leading to polymers with unimodal molecular weight distribution. In all systems, severe side reactions reduce conversions and molecular weights.
Interferenzeffekte von flüssigkristallinen block‐copolymeren (Einkettenrechnung)
Authors: Bonart Richard , Mulzer Georg
Published: April 2003

A previously derived so called BBB‐equation Bonart‐Blackwell‐Biswas11 gives the interference effect of fully elongated statistical copolymer chains taking into account the molecular structure of the monomers. It is a one‐chain calculation neglecting packing effects between neighbouring chains. Starting from the BBB‐equation and taking the A‐ and B‐sequences of A/B‐block copolymers as “super comonomers” a BM‐equation (Bonart‐Mulzer) is found to describe the interference effect of nonstatistical copolymers. The BM‐equation is close to the well known interference function for ideal lamellar stacks given by J. J. Hermans. It contains the length distributions u(z) of A‐and B‐sequences, which, in the case of statistical copolymers are given by Schulz‐Flory statistics. However, any other type of distributions u(z) and v(z) may be considered as well. The BM‐equation thus provides a possibility for the sequence analysis of fully elongated (liquid‐crystalline) non‐random copolymers by X‐ray scattering.
Reactivity of N‐alkylated cyclic iminoether salts having vinyl groups, 4. Radical polymerization and copolymerization of 3‐methyl‐2‐vinyl‐5,6‐dihydro‐4H‐1,3‐oxazinium trifluoromethanesulfonate
Authors: Miyamoto Masatoshi , Sano Yoshiyuki , Saegusa Takeo
Published: April 2003

Radical homopolymerization and copolymerizations of a new ionic monomer, 3‐methyl‐2‐vinyl‐5,6‐dihydro‐4H‐1,3‐oxazinium trifluoromethanesulfonate (2c), were studied. The homopolymerization was initiated with 2,2′‐azoisobutyronitrile or benzoyl peroxide in acetonitrile to produce a polymer, poly[1‐(3‐methyl‐5,6‐dihydro‐4H‐1,3‐oxazinium‐2‐yl)ethylene] (3c), with a relatively low solution viscosity ([η] ≈ 0,2). The monomer was found to be copolymerizable with both electron‐rich (styrene and butyl vinyl ether) and electron‐deficient monomers [methyl methacrylate (MMA)]. For the copolymerization of the monomer and MMA the reactivity ratios r1 = 0,31 and r2 = 0,37 (MMA) were determined. From these values the Q and e values were calculated to be 3,7 and 1,9, respectively. The e‐value is one of the highest among vinyl monomers reported thus far, which is consistent with the anionic polymerizability of monomer 2c.
Polymères thiocarboxyliques, 6. Réaction des dithiobenzoates d'ammonium quaternaire sur les chlorométhyloxiranne et ‐thiiranne; mise en évidence de la polymérisation anionique des thiirannes par les dithiocarboxylates d'ammonium quaternaire
Authors: Bonnans‐Plaisance Chantal , Levesque Guy
Published: April 2003

The reaction of quaternary ammonium dithiobenzoates (1) with chloromethyloxirane (2) leads to 1‐phenyl‐7‐oxa‐2,6‐dithiabicyclo[2.2.1]heptane (4) through participation of the thiocarbonyl group. According to the reaction conditions (temperature, concentrations) the same salts react with chloromethylthiirane (7) to give 1‐phenyl‐2,6,7‐trithiabicyclo[2.2.1]heptane (9) and/or substituted polymers of chloromethylthiirane. These results are explained considering the competition between monomolecular or biomolecular reaction paths involving addition of sulfide anions to the thiocarbonyl groups. The postulated reaction mecanisms are in agreement with the efficient anionic polymerization of methyl‐ and ethyl‐thiirane in the presence of quaternary ammonium dithiocarboxylates (aliphatic or aromatic).
Water‐soluble amino acid derivatives of syndiotactic poly(2‐methylallyl alcohol)
Authors: Dernst Christa , Klesper Ernst
Published: April 2003

Syndiotactic poly(2‐methylallyl alcohol) was esterified with protected amino acids and carbodiimides as condensing agents to obtain homopolymers with amino acid side chains. The amino acids glycine, L‐proline, and L‐serine and the α‐NH2 protecting groups tert‐butoxycarbonyl and benzyloxycarbonyl, and the OH protecting group tert‐butyl were employed. Consecutively, the blocking groups were removed from the polymers by acidolysis in HBr/CH3COOH to obtain the corresponding deprotected polymers. Potentiometric titration was used to study the water solubility and pKaa values of the deprotected polymers. All polymers were characterized with respect to structure and conversion by 1H and 13C NMR spectroscopy.
Synthesis and characterisation of poly(arylene sulfide)s, 5. Model compound studies of debromination reactions which occur during the synthesis of poly(arylene sulfide)s from copper(I) 4‐bromobenzenethiolates [copper(I) 4‐bromothiophenoxides]
Authors: Lovell Peter A. , Still Richard H.
Published: April 2003

Debromination side‐reactions which occur during the synthesis of poly(arylene sulfide)s from copper(I) 4‐bromothiophenoxides

Systematic name: Copper(I) 4‐bromobenzenethiolates.

were investigated using bromobenzene as a model for the end unit in a poly(1,4‐phenylene sulfide) chain. Model reactions were conducted in quinoline, pyridine, and 10:1 (v/v) quinoline/pyridine solution in the presence and absence of copper(I) bromide, the condensation product of polymerisation. Reaction liquors were subjected to GLC and MS analysis and evidence is presented which indicates that a copper(I) initiated debromination reaction occurs yielding monophenylquinolines. A mechanism is proposed for the reaction and critically discussed. The consequences of the reaction at the macromolecular level are also described.