Polydiethylsiloxane

The synthesis and phase behavior of the model polydiethylsiloxane networks have also been studied. The networks were made by hydrosilylation of well-defined vinyl and allyl telechelic siloxanes obtained by kinetically controlled polymerization of cyclic trisiloxane.314 The effects of molecular weight between the cross-linkings on segment orientation in polydiethylsiloxane elastomers were studied.315... 

Beatty CL, Pochan JM, Froix MF, Hinman DD (1975) Liquid crystalline type order in polydiethylsiloxane. Macromolecules 8 547... 

From the above results, it is clear that the presence of classical mesogens is not necessary for linear chains like poly(di-n-alkylsilane)s or poly(di-n-alkoxyphos-phazene)s [77] to show a mesomorphic behaviour. This concept has also been applied to the case of poly(di-n-alkylsiloxane)s. For aUcyl chains containing between 2 and 6 carbon atoms, the materials were shown to form a columnar mesophase, in which the molecules are positionally and orienta-tionally ordered in a two-dimensional hexagonal lattice, but along the chain no long range correlations exists [78]. The most famous member of this series of polysiloxanes is polydiethylsiloxane which exhibits at room temperature a... 

Dermuisene 511. See Rosin Derris. SeeRotenone Dervacid 3155. See Stearic acid DES. See Diethyl sulfate DES-T03, DES-T11, DES-T12, DES-T15, DES-T23. See Polydiethylsiloxane, triethylsiloxy-terminated... 

PDCB. See p-Dichlorobenzene PDCP. See Phenyl dichlorophosphate PDDB. See Domiphen bromide PDDP. See Diisodecylphenyl phosphite PDEA. See Phenyidiethanolamine PDES. See Polydiethylsiloxane p-PD HCI. See p-Phenylenediamine dihydrochloride... 

Trade Name Synonyms Lexorez 1721-65P [Inolex http //www.inolex.com] Polydiethylsiloxane CAS 63148-61-8]... 

NFPA Health 1, Flammability 1, Reactivity 0 Storage Store in cool, dry place keep containers tightly closed prevent contamination Uses Lubricant for arctic or space hydraulics Manuf./Distrib. Scientific Polymer Prods. http //www.scientificpolymer. com U nited Chem. Tech, http //www.unitedchem.com Polydiethylsiloxane, triethylsiloxy-terminated CAS 63148-61-8 Classification Silicone... 

FIGURE 60.8. Sound velocity of the longitudinal polarized phonon measured parallel (filled squares) and perpendicular (empty circles) to the draw direction measured by Brillouin scattering. The samples are polydiethylsiloxanes with Mn = 45,000 and 43,000 labeled as PDES-45 and PDES-3, respectively [15]. Reprinted from S.H. Anders, H.H. Krbecek, and M. Pietralla, J. Polym. Sci., Polym. Phys. Ed. 35, 1661-1676 (1997). Copyright 1997, with permission of Wiley-VCH. 

Molenberg, A. Siffrin, S. Moller, M., Well Defined Columnar Liquid Crystalline Polydiethylsiloxane. Makromol. Chem., Makromol. Symp. 1996,102, 199-207. 

Polydiethylsiloxane (PDES) is a polymer that exist in several polymorphs. This polymorphism along with the fact that the side chains can cause in principle increased mobility within the crystal make it a good candidate for a mesomorphic state forming material. After the first study of its thermal behavior [2] PDES became the subject of several investigations [3] and recently it was proposed that exist in two polymorphs a and Each one of them has a low and a high temperature phase (ai and a , i and ) [4,5]. In addition prior to the transition to the isotropic melt a so called mesomorphic or viscous crystal state am exists. 

The thermal stability of organosilicon dielectrics [10], liquids treated with ultrasound [11],has been studied. There are indications of an increase in stability to thermooxidative destruction for polydiethylsiloxane liquid polymers after the introduction of phenylnaphthylamine [12]. 

The stmctnre and phase transitions of polydiethylsiloxane were investigated with SFM at temperatures between 300 and 268 K. At room temperature, layers of polydiethylsiloxane are shown to be a mixture in both amorphous and mesomorphic states, while for a temperature of 273 K all material converts into the mesomorphic state (299). 

Phase Behaviour of the Mixtures of Polydiethylsiloxane with Oligomers of Dimethylsiloxanes... 

Although the rigidity increases slightly with an increase in the alkyl radical (in polydiethylsiloxane, = 1.75 [16], in polydipropylsiloxane... 

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