Hydrodynamic properties and statistical coil dimensions of poly(o-chlorostyrene)

The theta temperature for the system poly(o-chlorostyrene)-methyl ethyl ketone has been determined as 24·5°. The samples used in the determination were prepared by radical polymerization. The dependence of intrinsic viscosity on molecular weight has been measured in methyl ethyl ketone at 24·5° and found to be $\text{η}{}_{\mathrm{\theta }}\text{= 4·68 × 10}{}^{\mathrm{?4}}\text{M}{}_{\mathrm{<mtext>w</mtext>}}{}^{\mathrm{<mtext>M1</mtext><mtext>2</mtext>}}$. The ratio 〈s₌²〉/M was found, by light scattering, to be 5·60 × 10^?18 cm². Analysis of the solution properties indicates that the Kurata-Yamakawa theory is valid in the vicinity of the Flory temperature (UCST).     

Selective adsorption of PMMA in polar binary mixtures—I. Benzyl alcohol/n-bytyl alcohol and benzyl alcohol/sec-butyl alcohol mixtures

The behaviour of PMMA in two binary mixtures (benzyl alcohol/n-butyl alcohol and benzyl alcohol/sec-butyl alcohol) has been studied. There is an inversion in the solvation for the second mixture but not for the first. This behaviour has been explained by considering self-association of the alcohols of the binary mixture as well as the existence of specific interactions between sec-butyl alcohol and the polymer.     

Thermodynamic properties of trilaurylammonium bisulphate in benzene

We have studied the thermodynamic properties of trilaurylammonium bisulphate (TLAH₂SO₄) in benzene at several temperatures by vapour pressure osmometry (VPO). Values of the activity coefficients, γ_i, are given, which allows calculation of the excess thermodynamic functions, G^E, S^E and H^E.     

Formation of block copolymer micelles in solutions of a linear homopolymer in a good solvent

The existence of micelles of polystyrene-block-poly(ethylene/propene) in solutions of polystyrene in toluene was investigated. Toluene is a good solvent of both copolymer blocks whereas polystyrene and poly(ethylene/propene) are immiscible polymers. The presence of homopolystyrene at high enough concentration can induce the micellization of polystyrene-block-poly(ethylene/propene) in solution of a good solvent such as toluene. The thermodynamics of this new micelle system at a given polystyrene concentration was studied. Light scattering measurements were carried out in order to determine the critical micelle temperature (CMT) of different micellar solutions. Standard Gibbs energy, enthalpy and entropy of micellization were estimated from CMT and concentration data. The numerical values found were less negative than those found for micelle systems consisting in a block copolymer dissolved in a single selective solvent.     

Ftir study of hydrogen bonding and phase behaviour in poly(vinylpyridines)/poly(ethylene-CO-vinyl alcohol) blends

The specific interactions between polyvinylpyridines and ethylene-vinyl alcohol copolymers of different compositions have been studied by Fourier transform infrared spectroscopy (FTIR). Hydrogen bonding between both polymer components leads to significant spectral modification in pyridine rings spectral bands. Minor modifications in other spectral modes have been also detected. The spectral results indicate at least three competing equilibria processes in the blends: hydroxyl-hydroxyl copolymer self-association and hydroxyl-pyridine interassociation. Painter-Coleman association model was successfully applied and the phase diagram for these systems has been predicted.     

Acrylamide inverse microemulsion polymerization in a paraffinic solvent: Rolling‐M‐245

The inverse microemulsion polymerization of acrylamide in a paraffinic solvent, Rolling‐M‐245, stabilized by a mixture of nonionic surfactants (Emulan‐ELP‐11 and Brij‐92), was studied. Pseudoternary phase diagrams of this system were determined, and a range of hydrophilic‐lipophilic balance (HLB) values, from 8.98 to 9.2, were selected as the most favorable for acrylamide polymerization. The influence of factors such as the initiator composition, HLB, percentage of the aqueous phase, and addition of the monomer by steps on the final conversion and polyacrylamide molar masses were investigated. High conversions and molar masses were generally obtained with the different formulations. The polyacrylamide molar masses were influenced by the HLB and content in the aqueous phase. The addition of the aqueous phase by steps led to a progressive diminution of the molar masses as the number of stages increased. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2495–2503, 2005     

A series of mono and diesters of itaconic acid: Synthesis and structural determination

Summary A series of mono and diesters of itaconic acid containing alkoxy and sulfide side chains of variable lengths has been synthesized. Their structures have been established on the basis of their spectral data.

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Eine Serie von Mono- und Diestern von Itaconsäure: Synthese und Strukturbestimmung

Zusammenfassung Es wurde eine Serie von Mono- und Diestern von Itaconsäure mit Alkoxy- und Sulfidseitenketten variabler Länge synthetisiert. Die Strukturaufklärung erfolgte mittels spektroskopischer Daten.

     

Investigation of conformational transition in poly(cyclohexyl methacrylate)

The variations of intrinsic viscosity and refractive index increment with temperature for poly(cyclohexyl methacrylate) in isobutyl methyl ketone have been studied. A conformational transition has been found in the range 10–30°C. The influence of the molar volume of the side-group on the conformational transition temperature has also been discussed with respect to results for related polymers.     

Solution properties of poly(N-vinyl carbazole)—II. Thermodynamic properties in various solvents

Thermodynamic properties of dilute solutions of Poly-N-vinyl carbazole obtained by cationic polimerization have been studied by viscometry in various solvents. The validities of some excluded volume theories have been tested and the unperturbed dimensions have been calculated. The dependence of molecular dimensions, 〈s²〉, on molecular weight and viscometric equations have also been determined.