[PDF] High Temperature Elastomers A Systematic Series Of Linear Polycarborane Siloxanes Containing Icosahedral Cb10h10c Cages Ii Spectroscopic Identification eBook

Author : J. K. Gillham
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Page : 24 pages
File Size : 15,24 MB
Release : 1972
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Documentation and preliminary analysis of the infrared and NMR spectra of a systematic series of poly(carborane-siloxane)s containing the -CB10H10C- cage are reported. Inconsistencies in the spectra are interpreted in terms of complications in the syntheses. (Author).

Author : J. K. Gillham
Publisher :
Page : 45 pages
File Size : 11,71 MB
Release : 1972
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An extensive study of structure-bulk property relations for a systematic series of well defined linear poly(carborane-siloxane)s is reported. These polymers form the backbone components of recently developed high temperature elastomers. Thermomechanical spectra (about 1cps) from -180 C to 625 C to -180 C in nitrogen at 3.6 C/min and thermogravimetric data from 25 C to 800 C in argon are presented. Physical transitions (T(g), T(m), T(crys), Tsec) are discussed, including a correlation of T(g) data with structure using a copolymer equation. Thermostability is also discussed in terms of structure. (Author).

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Page : 26 pages
File Size : 29,75 MB
Release : 1972
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A study of oxidative instability versus molecular structure for a systematic series of well defined linear poly(carborane-siloxane)s is reported. These polymers form the backbone components of the most recently developed high temperature elastomers. Thermomechanical spectra in air (about 1 cps) from 130C to 625C to 130C at 3.6C/min, thermogravimetric data from 25C to 800C in air (3.6C/min) and differential thermal data from 25C to about 450C in air (15C/min) are presented. Thermo-oxidative stability is discussed in terms of structure and broad categories of behavior are defined.

Author : John K. Gillham
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Page : 17 pages
File Size : 48,62 MB
Release : 1972
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Nine poly(carborane-siloxane) high temperature elastomers which differ systematically in chemical structure were investigated by Torsional Braid Analysis. The structural variations include two different carborane cage structures in the polymer chain ( -CB10H10C- and -CB5H5C- ) and the step-wise increase in the number of -Si(CH3)2-O- linkages associated with each cage in the repeat unit. Polydimethyl-siloxane was studied as the compositional limit of both series. The dynamic mechanical relaxations (about 1 cps) of the materials are reported. These include the melting points of the semi-crystalline polymers, and the glass transitions and secondary transitions of all the polymers. The glass transition temperatures in each series were systematized using a well known copolymer composition versus glass transition temperature relationship. (Author).

Author : John K. Gillham
Publisher :
Page : 17 pages
File Size : 29,68 MB
Release : 1972
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ISBN :

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Previously reported results related glass transition temperature to structure in two systematic series of poly(carborane-siloxane)s using a well known copolymer composition-glass transition relationship. The relationship was originally proposed to apply not only to copolymers, but also to diluent systems. Accordingly, mixtures of polymers within each series were prepared and the thermomechanical spectra were determined by the technique of Torsional Braid Analysis. The binary mixtures included polydimethyl-siloxane with polymers in both series and a mixture of two -CB10H10C- siloxane polymers. In all cases, the thermomechanical spectra revealed only those transition regions characteristic of the individual components. (Author).