Polysiloxane Elastomers via Room Temperature, Metal-Free Click Chemistry

Novel cross-linkers for PDMS networks for controlled and well distributed grafting of functionalities by click chemistry

“…[9][10][11][12] Click chemistry has previously been demonstrated to be successful for functionalization of polymers in general polysiloxanes in particular. [16][17][18][19] The azide group on the crosslinker therefore enables reactions with various types of alkyne functional molecules and thereby signicantly widens the functionality that can be introduced into PDMS elastomers. Therefore a number of different functionalities are elaborated.…”

Thermally controlled silicone functionalization using selective Huisgen reactions

“…The progenitor reaction, the Huisgen cyclization [7], by contrast, is less attractive at first glance in that higher temperatures are generally needed to induce [3 + 2]-cyclization, and a mixture of both regioisomers is the normal outcome of the process. Another major drawback of the Huisgen cycloaddition is the slow reaction rate: there is a $10 7 difference in the rate of the Huisgen when compared to an analogous CuAAC reaction at room temperature [8].…”

“…For example, Gonzaga et al [7] demonstrated that room temperature crosslinking of silicones was possible using Huisgen cycloaddition of propiolate-functionalized polysiloxanes with bisazide-functionalized poly(ethylene glycol): the process was extended to the generation of dendrimers based on acetylene dicarboxylates, a functional group that is unreactive with CuAAC chemistry [10]. Perhaps the most clever utilization of the reaction with electron-deficient alkynes, however, is the use of trifluoro-substituted or ring-strained alkynes by Bertozzi et al [11].…”

Synthesis of telechelic vinyl/allyl functional siloxane copolymers with structural control

“…Furthermore, various functional groups along the backbone of the copolymers open up, for example, Williamson ether syntheses or copper-catalysed cycloaddition reactions of azides and alkynes (CuAAC) forming 1,4-disubstituted-1,2,3-triazoles, a so-called "click" reaction. [21][22][23][24] Click reactions, which previously have been used to functionalise polymers in general [25][26][27][28] and polysiloxanes in particular, [29][30][31][32] are particularly efficient in the functionalization of polymers, as they do not form any byproducts and yields are often high.…”