[PDF] High Temperature Elastomers Glass Transition Structure Correlations For Two Systematic Series Of Linear Polycarborane Siloxanes Ii Incompatibility eBook

Author : John K. Gillham
Publisher :
Page : 17 pages
File Size : 12,20 MB
Release : 1972
Category :
ISBN :

GET BOOK

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).

Author : John K. Gillham
Publisher :
Page : 17 pages
File Size : 32,78 MB
Release : 1972
Category :
ISBN :

GET BOOK

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 : American Chemical Society. Committee on Professional Training
Publisher :
Page : 920 pages
File Size : 44,15 MB
Release : 1974
Category : Biochemistry
ISBN :

GET BOOK

Faculties, publications and doctoral theses in departments or divisions of chemistry, chemical engineering, biochemistry and pharmaceutical and/or medicinal chemistry at universities in the United States and Canada.

Author : RP. Chartoff
Publisher :
Page : 13 pages
File Size : 14,72 MB
Release : 1994
Category : Cure
ISBN :

GET BOOK

The glass transition temperature of polymers depends on both the experimental procedures and the experimental techniques used for its evaluation. However, the value of the published data is often diminished because these details are omitted. Examples are cited to show how the magnitude of differential scanning calorimetry (DSC) Tg depends on the Tg location and different calibration methods. Some comments are also made about thermomechanical analysis (TMA) and dynamic mechanical analysis (DMA) methods, although these are treated only briefly.

Author : E. Donth
Publisher : Springer Science & Business Media
Page : 433 pages
File Size : 22,70 MB
Release : 2013-04-17
Category : Science
ISBN : 3662043653

GET BOOK

Describes and interrelates the following processes: cooperative alpha processes in a cold liquid, structural relaxation in the glass near Tg, the Johari-Goldstein beta process, the Williams-Götze process in a warm liquid, fast nonactivated cage rattling and boson peak, and ultraslow Fischer modes.