A Dioxasilepane-Functionalized Styrenic Monomer as a Platform for Novel Silicon-Containing Polystyrenes
Year: 2026
Type: preprint
Abstract: A dioxasilepane-derived styrenic monomer, 2,4,4,7,7-pentamethyl-2-(4-vinylphenyl)-1,3,2-dioxasilepane (St-Si(pan)Me), is introduced as the first polymerizable representative of the recently developed Si(pan) platform, a seven-membered cyclic dialkoxysilane motif combining high stability with controllable silicon reactivity. The monomer combines the exceptional kinetic stability of the seven-membered cyclic dialkoxysilane with a polymerizable styrenic functionality, enabling direct incorporation of the Si(pan) motif into polystyrene-based polymers and materials. Following multigram-scale synthesis, the compatibility of St-Si(pan)Me with conventional free-radical polymerization was systematically investigated. Among the investigated polymerization temperatures (70 - 90 °C), 90 °C provided the best balance between molar-mass distribution, structural fidelity, thermal stability, and photophysical performance while fully preserving the integrity of the Si(pan) framework. Beyond free radical polymerization, Reversible Addition-Fragmentation Chain-Transfer (RAFT) polymerization showed compatibility with controlled radical polymerization, while preliminary emulsion polymerization revealed distinct behavior under aqueous conditions, suggesting opportunities for future siloxane network formation. Copolymerization with styrene afforded silicon-functionalized copolymers with tuneable compositions and systematically adjustable molecular, thermal, and photophysical properties. Comprehensive characterization by various techniques confirmed successful incorporation of the Si(pan) functionality throughout the polymer series. This work establishes St-Si(pan)Me as a versatile platform monomer that expands the toolbox of silicon-functionalized styrenes and provides access to a new class of thermally robust and intrinsically luminescent silicon-containing polystyrenes.
Source: ChemRxiv
Language: English
Subfield: Organic Chemistry
Field: Chemistry
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7223102785