Hannele Järvinen

Counter-ion induced processibility of polyaniline: conducting melt-processible polymer blends

Summary form only given. Conducting polymer blends made by blending thermoplastic bulk polymers with Polarene/sup TM/, a proprietary conducting polyaniline composition, using conventional melt-processing techniques are reported. The percolation threshold for conductivity is observed at astonishingly low weight fractions of the conjugated conducting polyaniline indicating the formation of a unique morphology. Results on electrical and mechanical properties of these blends will be presented and discussed.

Electrically conductive compositions based on processible polyanilines — PANEPOL TM

Abstract Truly melt- and solution processible electrically conductive polyaniline (PANI) compositions can be produced commercially utilizing the technology originally developed some years ago in a joint-effort between Neste Oy and UNIAX Corporation. This technology, PANIPOL TM , utilizes PANI protonated by functionalized protonic acids in combination with proprietary plasticizers. Neste has now further developed this technology and reached semi-industrial scale production capabilities. We briefly discuss some features of fusible, conductive PANIPOL TM compositions developed specifically for use in conductive products such as injection molded articles, extruded films and fibers.

Qualitative and quantitative end-group analysis of a small molecular weight polyester by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

Matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry was used for qualitative and quantitative end-group analysis of a small molecular weight polyester, poly(2-butyl-2-ethyl-1,3-propylene phthalate). The presence of carboxyl-terminated linear and cyclic polyester oligomers was confirmed with the help of simple sample preparation methods. The presence of carboxyl end-groups in the polyester chains was verified through their formation of carboxylate salts with alkali metal cations. Cyclic oligomers were identified through deuterium exchange of the exchangeable protons of the polyester. Various inorganic salts were tested for salt formation of the carboxyl end-groups, but only the alkali metal salts proved effective. The influence of the alkali metal salts on the results of the quantitative end-group analysis was also studied. The relative amounts of differently terminated and cyclic oligomers were calculated when the alkali metal salts were used with different matrices. The results showed that both the salts and the matrices used in sample preparation can have a marked effect on the quantitative results of the end-group analysis. The measurements were carried out using 2,5-dihydroxybenzoic acid (DHB), 1,8, 9-trihydroxyanthracene (dithranol), and 2-(4-hydroxyphenylazo)benzoic acid (HABA) as matrix compounds. Dithranol and HABA repeatably exhibited similar results, and these results differed from those obtained with DHB probably because of the different ionization mechanisms in the MALDI process.

Structural characterization of aromatic polyester resins by matrix-assisted laser desorption/ionization mass spectrometry

Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry was used to characterize average molecular weights and end-groups of synthetic aromatic polyesters and the same characteristics were also determined for acetylated polyester samples. In addition, the progress of a polyesterification reaction was followed by mass spectrometry by investigating samples taken from the reaction mixture at different reaction times. Average molecular weights were compared with those measured by gel-permeation chromatography (GPC) and the results of quantitative end-group analysis were considered with the acid values of the polyesters. MALDI measurements were carried out using two different matrix compounds, 2,5-dihydroxybenzoic acid (DHB) and 2-(4-hydroxyphenylazo) benzoic acid (HABA). Different matrices and derivatization of the polyester influenced the width of the polymer distribution determined by mass spectrometry and further affected the proportions of differently terminated oligomers, in addition to the average molecular weight. The relative amount of the most abundant oligomer species was increased when the polymer distribution width was increased.

Electrically conducting blends of polyaniline

Summary form only given. A melt-processable, conducting polyaniline composition, Polarene/sup TM/ has recently been developed. This composition allows blending and processing using conventional techniques. In this study we present results on electrical conductivity, blend morphology and mechanical properties of conducting binary blends comprising Polarene/sup TM/ and polypropylene or polystyrene, respectively.