The crystal structure of polytetrahydrofuran

Cesari, M.; Perego, G.; Mazzei, A.

doi:10.1002/macp.1965.020830117

Cited by 67 publications

(28 citation statements)

References 4 publications

(1 reference statement)

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“…This film p e r m e a b i l i t y to ions is probably due to the fact that the polymer chains are parallel and regularly spaced, thus having a p a r t i a l l y crystalline character, as has been shown in the case of bulk p o l y -T H F (25,26). Experiments on this point are currently under way.…”

Section: Resultsmentioning

confidence: 85%

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Tourillon

Dubois

Lacaze

1978

J. Electrochem. Soc.

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The surface changes occurring when a platinum electrode is anodieally polarized in THF-LiC104 or in THF-LiCIO~-9,10 dip'henylanthracene (DPA) are detected and investigated by means of polaromicrotribometry (PMT). The formation of a 'homogeneous film on the metal surface is associated with a very small value of the friction coefficient. The thickness of this film, designated by the general symbol PtITHF, LiC104, Oxl, may be adjusted from 100 to 5000A. It appears as a very pure variety of polyTHF, uncontaminated by the electrolyte. Multiple-reflection infrared spectroscopy and x-ray photoelectron spectroscopy (XPS) are used to determine its structure. Its formation results from the polymerization of THF via an ionic mechanism initiated by C104" or DPA" + radicals. It only occurs if the water content is less than 250 ppm. This film has well-defined physical properties: a marked hydrophobicity, very strong adherence on the platinum surface, and great homogeneity; although it is a nonconductor out of the solution, its porous structure makes it a conductor in electrolyte solution.The development of the technology in the area in microelectronics and, more recently, in that of integrated optics is more and more dependent on different methods of elaborating organic or mineral films (1). In the case of organic films, numerous techniques for deposition on metallic surfaces have been described. The most common methods are based on vapor deposition or sublimation (1), adsorption (2) or polymerization of an organic vapor subjected to electronic bombardment (3) or to an electric discharge (4). Electrochemical techniques can also be used for the elaboration of mineral or organic films, applicable to the previous areas. The film quality (purity, adherence, and homogeneity) depends on the Chemical system chosen, on the polarization conditions, and also on the choice of the chemical medium in which the electrode reaction is occurring. Generally speaking, it is possible to obtain an organic polymer film adsorbed on a metallic surface by oxidizing or reducing a compound which produces polymerizable radical or ionic species. The chosen reagent may either be a monomer dissolved in a solvent, or the solvent itself. The THF example belongs to this latter case, and in a previous work (5) we show that several mineral films are formed on the electrode under cathodic polarization.The polymerization of THF by chemical (6) or electrochemical (7-10) means has already been described in the literature, but it is only related to the formation of the dissolved polymer in solution. As far as we know, no study has been devoted to the phenomena which occur on the electrode surface for an anodic polarization.By using the PMT technique (11, 12), we have been a~ble to show important modifications of the platinum surface in the anodic zone. These are related to the appearance of a deposit which could not be detected * Electrochemical Society Active Member. by analysis of the i-E curves alone. This first observation is confirmed by means of other analytica...

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Section: Resultsmentioning

confidence: 85%

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Tourillon

Dubois

Lacaze

1978

J. Electrochem. Soc.

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“…Heat of fusion of PTMO used for this estimation is equal to 200 J/g. [30] DSC data show the profound effect of chemical composition of studied copolymer on melting and crystallisation of PBT block. The melting temperature of PBTblocks decreases from 211 to 158 8C with the increasing of soft block content from 35 to 60% (MW of the soft block equals 1 000).…”

Section: Resultsmentioning

confidence: 99%

“…There are no traces of the b-form of PBT [22,34] and crystalline phase of PTMO. [30] The estimated total degrees of crystallinity are equal to 20 and 5% for 1 000/35 and 1 000/60, respectively, corresponding nicely to the crystallinities determined by DSC (Table 2) normalised on PBT content.…”

Section: Structure Of As-prepared Samplesmentioning

confidence: 89%

Deformation of Polyether-Polyester Thermoelastoplastics: Mechanothermal and Structural Characterisation

Konyukhova

Neverov

Godovsky

et al. 2002

Macromol. Mater. Eng.

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“…PTMG itself forms a monoclinic structure 14) above a certain molecular weight. This structure has also been obtained for PTMG with NH, end-groups used for block copolymer synthesis.…”

Section: Phase Behaviour Of the Polymersmentioning

confidence: 99%

Thermotropic elastomers with poly(oxy‐1,4‐butanediyl) units in the main chain

Pospiech

Komber

Voigt

et al. 1994

Macro Chemistry & Physics

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The paper describes the synthesis of thermotropic elastomers from trimellitimide-terminated poly(oxy-l,4-butanediyl) [synonyms: poly(tetramethy1ene ether glycol), PTMG; poly(tetrahydr0-furan), poly(THF)] and acetoxy group-terminated rigid blocks. Copolyester imides are formed by transesterification polycondensation in the melt. According to I3C NMR investigations, their chain sequence distribution is characterized by a block-like structure in which the preformed rigid units are partially exchanged by transesterification reactions during the melt polycondensation. The degree of transesterification depends on the reaction time. The influence of the length of the flexible FTMG units and of the concentration of rigid units on the phase behaviour as well as on the thermal behaviour and the dynamic-mechanical behaviour of the block copolymers is discussed with respect to aromatic model compounds.

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The crystal structure of polytetrahydrofuran

Cited by 67 publications

References 4 publications

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Polaromicrotribometric (PMT) and Spectroscopic (Infrared‐XPS) Study of the Formation and Modifications of Films Formed on a Polarized Platinum Electrode in THF ‐ LiClO4 Medium: II . Anodic Polarization

Deformation of Polyether-Polyester Thermoelastoplastics: Mechanothermal and Structural Characterisation

Thermotropic elastomers with poly(oxy‐1,4‐butanediyl) units in the main chain

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