Journal ArticleDOI
Comparison of the cationic polymerization of octamethylcyclotetrasiloxane and hexamethylcyclotrisiloxane
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TLDR
In this article, features of the cationic polymerization of hexamethylcyclotrisiloxane (D3) in methylene chloride in the presence of a strong protonic acid (CF3SO3H) were compared.Abstract:
Some features of the cationic polymerization of hexamethylcyclotrisiloxane (D3) and octamethylcyclotetrasiloxane (D4) in methylene chloride in the presence of a strong protonic acid (CF3SO3H) were compared. The polymerizations of both these monomers show many similarities, which are taken as evidence for analogies in their mechanisms. In particular, in both cases the reaction is affected by the addition of a small amount of water. The role of water is interpreted in terms of its direct participation in some elementary reactions of the process. The addition of water affects also the state of hydrogen bonding association in the system. Some experimental results together with comments concerning the mechanism of ring formation in the polymerization system are included.read more
Citations
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Journal ArticleDOI
Mechanism of the Acid-Catalyzed Si−O Bond Cleavage in Siloxanes and Siloxanols. A Theoretical Study
and Marek Cypryk,Yitzhak Apeloig +1 more
TL;DR: Theoretical ab initio calculations were carried out to simulate the hydrolysis of the siloxane bond under neutral and acidic conditions in this article, where the most important factors reducing the energy barrier of the reaction are the protonation of the nucleophile (acid catalysis) and the basic assistance provided by hydrogen bond complexes, which help to transfer a proton from a nucleophile to the leaving group.
Journal ArticleDOI
Hydrophobic/superhydrophobic oxidized metal surfaces showing negligible contact angle hysteresis.
TL;DR: Dynamic wettability of oxidized metal surfaces could be tuned by chemical vapor deposition (CVD) of 1,3,5,7-tetramethylcyclotetrasiloxane (D(4)(H)) by changing the CVD temperature, resulting in a marked difference in the final wetting properties.
Book ChapterDOI
Synthesis of Linear Polysiloxanes
Julian Chojnowski,Marek Cypryk +1 more
TL;DR: For a detailed review of the reactions used in polysiloxane synthesis, see, e.g., the authors and the references therein [2]. But the main focus of this paper is on the reactions that lead to polysiloxide synthesis.
Journal ArticleDOI
Kinetically controlled siloxane ring-opening polymerization
TL;DR: In this article, some basic aspects of the kinetics and mechanisms of anionic and cationic ring-opening polymerization of cyclic siloxanes are discussed in connection with their use in polymer synthesis.
Journal ArticleDOI
New developments in cationic polymerization of cyclosiloxanes
TL;DR: In this paper, the analogies or the differences in the behavior of cyclosiloxanes of various sizes (particularly D3 and D4) when they are initiated by triflic acid are discussed.
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