Facile synthesis of cyclosiloxane-based polymers for hybrid film formation

Abstract

A one-pot facile synthesis of cyclosiloxane-based hybrid polymers based on hydrosilylation reaction and their network polymer film formation via self-crosslinking by hydrolysis/condensation reactions are reported.

Synthesis and characterization of siloxane‐based cyanate ester elastomers from readily available materials: a top‐down approach

“…appear to exhibit a two‐step mass loss event. The first, lower temperature event is assigned to Si—C and C—C bond cleavage, whereas the second event is attributed to the redistribution of the siloxane network . With the exception of SiCE‐H41 and SiCE‐H25, the onset of degradation ( T d ) and char yields appear to increase as the amount of siloxane component is increased.…”

“…The SiCE‐MTDMSS and SiCE‐PTDMSS elastomers also had the lowest char yields at approximately 25%. Upon thermal decomposition, these elastomers would produce mostly silicon dioxide (SiO 2 ) and silicon oxycarbide (Si x O y C z ) char . Being of lowest content of siloxane, the char yields should be reduced with respect to those elastomers containing the siloxane pre‐polymers.…”

“…The first, lower temperature event is assigned to Si-C and C-C bond cleavage, whereas the second event is attributed to the redistribution of the siloxane network. 37,38 With the exception of SiCE-H41 and SiCE-H25, the onset of degradation (T d ) and char yields appear to increase as the amount of siloxane component is increased. Furthermore, by crosslinking the pre-polymers with TAC, the T d values are shifted upwards by between 40 and 250 ∘ C depending on the pre-polymer employed.…”

“…Upon thermal decomposition, these elastomers would produce mostly silicon dioxide (SiO 2 ) and silicon 544 www.soci.org AR Jennings et al oxycarbide (Si x O y C z ) char. 38,41 Being of lowest content of siloxane, the char yields should be reduced with respect to those elastomers containing the siloxane pre-polymers. In transitioning to the formulation prepared using the lowest molecular weight siloxane pre-polymer (1000-1100 g mol −1 ), SiCE-H11, T d is shifted upwards by nearly 100 ∘ C and is assigned to the increased thermochemical stability arising from the incorporation of the siloxane pre-polymer.…”

Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes

“…[1][2][3][4] The physical properties and performance of siloxane-based materials depend substantially on their structures.I nt he design of siloxane-based materials on the molecular scale to the mesoscale, ab uilding-block approachu sing oligosiloxanes with specific structures exhibits potential. [5] Until now,o ligosiloxanes with linear, [6] branched, [7,8] ladder-like, [9,10] cyclic, [11][12][13][14][15][16] or cage structures [17,18] have been used as building blockst op roduce soluble polymers with organic or siloxane linkers, [11,16,19,20] three-dimensionally crosslinked microporous materials, [12,17,[21][22][23][24] ordered mesostructured materials, [6-8, 14, 18, 25, 26] and crystalline zeolitic materials. [27,28] Oligosiloxanes with polycyclic and cage structures are of particular interest because they are the basic structural units of crystalline silica materials, such as layered silicate and zeolites.…”