High-temperature polymer polysiloxane

Polyphenylene sulfide, see High-temperature polymers Polysiloxane... 

Jeske, M., Soltmann, C., Ellenberg, C., Wilhelm, M., Koch, D. and Grathwohl, G. 2007. Proton conducting membranes for the high temperature-polymer electrolyte membrane-fuel cell (HT-PEMFC) based on functionalized polysiloxanes. 

Tian SB,Pak YS,Xu G (1994) Polyimide-polysiloxane-segmented copolymers as high temperature polymer electrolytes. J Polym Sci Part B Polym Physics 32 2019... 

Development has been conducted to fabricate SiC-based matrix/Si-C-based fiber composites by polymer infiltration. Nicalon fibers are used, and various polymers such as polysilazanes, polysiloxanes, and polycarbosilanes are used to yield matrices of SiCO, SiNC, and SiC. As with CVI of SiC/SiC composites, carbon acts as an interface layer but does not result in stability at high temperatures. 

Applications. Polymers with small alkyl substituents are ideal candidates for elastomer formulation because of quite low temperature flexibility, hydrolytic and chemical stability, and high temperature stability. In light of the biocompatibilily of polysiloxanes and P-O- and P-N-suhslituted ptilyphosphazenes. polytalkyl/arylphosphazenes) are also likely lo he hiocompatible polymers. A third potential application is in the area of solid-state batteries. 

Applications. Polymers with small alkyl substituents, particularly (13), are ideal candidates for elastomer formulation because of quite low temperature flexibility, hydrolytic and chemical stability, and high temperature stability. The ability to readily incorporate other substituents (in addition to methyl), particularly vinyl groups, should provide for conventional cure sites. In light of the biocompatibility of polysiloxanes and P—O- and P—N-substituted polyphosphazenes, poly(alkyl/arylphosphazenes) are also likely to be biocompatible polymers. Therefore, biomedical applications can also be envisaged for (3). A third potential application is in the area of solid-state batteries. The first steps toward ionic conductivity have been observed with polymers (13) and (15) using lithium and silver salts (78). 

The main polymers of this type are poly-dimethylsiloxane (PDMS), and polymethylphe-nylsiloxane (PMPhS). Their T = -127 and -86°C, respectively. They start oxidizing at 290 and 375°C and undergo structural rearrangement at 435 and 410°C. Polysiloxanes have been used as high temperature impact modifiers that improve... 

F. Fenouillot, F. Mechin, F. Boisson, P. Alcouffe, T. Pokropski, T. KaUel, M. Mnif, Coarsening of nanodomains by reorganization of polysiloxane segments at high temperature in polyurethane/a,co-aminopropyl polydimethylsiloxane blends, European Polymer Journal 48 (2) (2012) 284-295. 

For example, if one wants a polymer for fire-resistant fabrics, then a polymer with good high-temperature properties is required, which implies aromatic structures, which suggest condensation polymerizations. More relevant here, however, would be that a polymer remains elastomeric at low temperatures. This requirement evokes a polymer with high flexibility (low glass transition temperature), which indicates use of the polymerization techniques used with the polysiloxanes. 

Siloxane polymers possess a number of properties that seem almost contradictory. One example is the tremendous stability and durability shown by polysiloxanes in a wide variety of applications. One reason for this stability is the fact that the chain is already in a high oxidation state, and reduction takes place only at very high temperatures. Most scientists... 

Ogawa, T. Watanabe, J. Eguchi, K. Oshima, Y., Synthesis of Polysiloxane-Modified Hybrid Particles by a High Temperature Water Technology. Polymer 2010,51, 2836-2842. 

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