Amphiphilic sorbents based on polysiloxanes crosslinked by anN,N′-heterocycle

Abstract

New amphiphilic sorbents have been synthesized by crosslinking of the chloromethyl sidefunctionalized polysiloxanes with piperazine. Three structures, differing by the crosslinking degree, have been synthesized as potential sensitive materials for humidity sensors able to work at high humidity or as metal sorbents. Correlations between structure and morphology of the polymeric matrix, as well as their swelling capacity in solvents with different polarities, are discussed.

Amphiphile polydimethylsiloxane‐based networks reinforced with in situ generated silica

“…Thus, it can be observed that highly crosslinked sample P3 (based on a high‐functionalized polysiloxane precursor, CMCl3) has the higher water uptake ability (Table 1). This is different from the crosslinked pure polydimethylsiloxane (PDMS), which has a negligible water sorption capacity but uptakes chloroform in high amount [4]. Such behavior is due to the fact that the crosslinker in sample P3 is a hydrophilic one that favors the water sorption.…”

“…Poly[(chloromethyl)methylsiloxane]‐α,ω‐diol (MCl) was synthesized according to a modified procedure described in Refs 4. and8: water (3.6 ml; 0.2 mol) was slowly added to stirring solution containing 16.35‐g (0.1 mol) CMCl in 40‐ml diethyl ether (Scheme ).…”

“…Either linear or crosslinked polysiloxanes can be functionalized with hydrophilic groups. The crosslinked structures can be functionalized with hydrophilic groups before [3], during [4, 5], or after crosslinking process [6]. The utilization of crosslinkable polymers able to generate ionic sites in the crosslinked state is an interesting approach [1].…”

“…Thus, the amination of the oligo(chloromethylsiloxane)s with either an excess or an insufficient amount of 4,4′‐dipyridyl led to water‐soluble or crosslinked polymers, respectively, which proved to have electrochromic and redox properties, to interact with divalent metal chlorides, to act as catalysts, or to be useful for the purification of hormones and antibiotics [5]. Oligo(chloromethylsiloxane)s have also been crosslinked with piperazine to obtain materials useful in humidity sensors [4]. Mixed networks containing hydrophobic sequences with ionic crosslinking points were formed.…”

Synthesis Optimization of Novel Cross-Linked Polysiloxane with End-capped Epoxy Groups as Waterproofing Agent for Fabric

“…Until now, the cross-linked polysiloxanes have been fabricated by heat-or photo-initiated polymerization of silicones with the pendant double bonds [16,17] , moisture curing of silicone compositions through hydrolysis=condensation reactions [18] , chemical reactions between the functional groups from different components such as chloromethyl and piperazine [19] , amino and epoxy groups [20] , amino and 1, 2, 4, 5-benzenetetracarboxylic dianhydride [10] , hydroxyl and isocyanate groups [21] , and more frequently by the hydrosilylation cross-linking method [13][14][15][22][23][24] . However, detailed information concerning their synthesis parameters using the hydrosilylation cross-linking method is still scarce.…”