British Polymer Journal 

About: British Polymer Journal is an academic journal. The journal publishes majorly in the area(s): Polymer & Polymerization. It has an ISSN identifier of 0007-1641. Over the lifetime, 1217 publications have been published receiving 17898 citations.

Electrical conductivity in ionic complexes of poly(ethylene oxide)

Abstract: The temperature dependence of d.c. conductivity of poly(ethylene oxide) complexes with sodium iodide and the thiocyanates of sodium, potassium and ammonium has been investigated. In each case a transition to a lower activation energy at higher temperatures was observed. For the sodium complexes this transition occurs at ca 55°C which is well below the crystalline melting points at 200°C. For the potassium and ammonium complexes however, the transitions coincide with the melting points at ca 100 and 70°C respectively. It is proposed that at the transitions, thermal disintegration of complexes in the amorphous regions occurs. The complexes involve coordination of the cations to the ether oxygen atoms in the polymer backbone.

The preparation and characterisation of polymer latices formed in the absence of surface active agents

Abstract: Methods have been devised for the formation of monodisperse polystyrene latices in the absence of added surface active agents. The particles are stabilised, as a colloidal dispersion, by surface groupings which are an integral part of the particle and are not removed by dialysis. By suitable variation of the ionic strength of the aqueous phase, the initiator concentration and the polymerisation temperature, the final particle size obtained in single-stage reactions was varied between c. 0.15 and 1.0 μm. The coefficient of variation on particle diameters was usually less than 5%. The ionic strength of the aqueous phase was found to play an important part in determining particle size; this was explained in terms of a limited coagulation process occurring at the stage involving the nucleation of polymer particles. Conductometric titration experiments revealed the presence of sulphate, carboxyl and hydroxyl groups on the particle surfaces. Molecular weight determination of the polystyrene formed showed that this was lower than that formed in conventional emulsion polymerisation.

Monodisperse polymeric spheres in the micron size range by a single step process

Abstract: A method for the formation of monodisperse polystyrene (PS) and polymethylmethacrylate (PMMA) spheres, in the micron diameter range, was developed. The polymerisation reaction was carried out in a series of alcohols, using homo- and co-polymers as steric stabilisers in combination with a quaternary ammonium salt which probably acts as an electrostatic co-stabiliser. Monodisperse PS spheres were formed in the particle size range of 1–6 μm, by a single step process. The size range could be extended by further addition of monomer to the reaction mixture during the polymerisation. The solubility parameter of the alcohol used and the nature of the surfactant determine the diameter of the resulting spheres. However, the concentration of surfactant did not seem to affect strongly the size of the spheres but only the dispersity.

A sulphonated poly(aryl ether ketone)

Abstract: Sulfonation et neutralisation controlees de PEEK, caracterisation de PEEK sulfone et effet de cette modification sur la cristallinite, les transitions thermiques et la stabilite thermique

Thermotropic Liquid Crystalline Polyesters with Rigid or Flexible Spacer Groups

Abstract: Several different series of rigid and flexible polyesters with main chain liquid crystalline units were prepared and their properties were examined in relation to their structures. The first group of polymers were rigid aromatic copolyesters with mesogenic groups based on either chloro or methyl hydroquinone terephthalate units combined with varying amounts of different types of bisphenol terephthalate units The bisphenol comonomers used contained the structure: in which X was none, C(CH3)2, CH2, O, S, and So2. It was observed that the bisphenols with the bulkier X group were more efficient in destroying thermotropic liquid crystallinity of the resulting copolymers. The second group of polymers studied were flexible polyesters consisting of various types of mesogenic units which were connected together by different lengths of polymethylene flexible spacers. The liquid crystalline behaviours of these polymers, particularly their transition temperatures, were correlated with their structures. A brief review of previous studies on the synthesis of thermotropic liquid crystalline polyesters is included.