The synthesis and X-ray diffraction study of the ladder-like polysilsesquioxanes with side-chain ester groups

Free-standing, polysilsesquioxane-based inorganic/organic hybrid membranes for gas separations

“…Cage-like PSSQ structure shows a single strong and broad absorption peak at $ 1100 cm À 1 for the -Si-O-Si-bond stretching, while ladder-like structures exhibit two asymmetric absorption peaks at 1020-1150 cm À 1 for the same bond [23,25,38,39]. The FT-IR spectra for our LPG64 membrane demonstrate that it contains an epoxide group (908 cm À 1 ), a phenyl group (2800-3100, 1594, 1430 cm À 1 ) and a ladder-like PSSQ backbone (1020 and 1090 cm À 1 ) (See Fig.…”

“…Unfortunately, their PSSQs were proven to be partial cage-like structured by Frye et al [24]. Since then, a series of ladderlike PSSQs with different organic functional groups were developed [25][26][27][28]. For instance, Cao et al synthesized the ladder-like copolymethyl-hydrosilsesquioxane (Me-H-T) and ladder-like copolymethyl-epoxysilsesquioxane (CPMES) [29].…”

Synthesis and characterization of ladder-like structured polysilsesquioxane with carbazole group

“…The first sharp peak (a) was characteristic of the intramolecular periodic chain-to-chain distance (d 1 = 15.6 Å), thus the distance between two carbarzole pendant groups through the ladder structured siloxane backbone, while the second diffused peak (b) indicated the average thickness of the siloxane backbone (d 2 = 4.3 Å). 21,22 The simulation result as a single molecule (Chem 3D Ultra 8.0; Cambridge Soft Co.) showed that d 1 and d 2 were 19.0 and 4.1 Å, respectively. Although the d 1 was slightly longer than the experimental result, this was probably due to some aggregation of the flexible propylene spacer between the carbarzole group and the silicon atom in the bulk sample.…”

Synthesis and characterization of polyorganosiloxane (POS) containing nano‐scale tubular structure and its supramolecular clathrate

“…Since the 1980s our group has developed a new synthetic method namely stepwise coupling polymerization (SCP) for preparing reactive ladder-like polysilsesquioxanes [9] Different from previous alkali-catalyzed equilibrium reaction process [10], in this synthetic process, 1,4-phenylenediamine (PDA) is used as template agent to facilitate the regular arrangement of the monomers and intermediates in the condensation process. As a result, relatively structure-ordered ladder-like polysilsesquioxanes with cis-isotactic configuration, such as polyestersilsesquioxane (Ester-T), polyvinyl (or allyl)silsesquioxane (Vi-T or Allyl-T) and polyhydrosilsesquioxane (H-T) etc., are obtained, which can be used as starting materials to further construct other advanced polymers such as TPs [11,12].…”