# Synthesis of Polyfluorinated Aromatic Selenide-Modified Polysiloxanes: Enhanced Thermal Stability, Hydrophobicity, and Noncovalent Modification Potential

## TL;DR

This paper introduces a new method to modify polysiloxanes using noncovalent interactions, resulting in materials with better thermal stability and water resistance.

## Contribution

A novel dual-functionality approach combining selenium-based and polyfluoroaromatic groups in polysiloxanes is introduced.

## Key findings

- Modified polysiloxanes showed up to 37 °C higher thermal decomposition temperatures.
- Water contact angles increased from 69° to 102°, indicating improved hydrophobicity.
- The method achieved high substitution degrees (74–98%) under mild conditions.

## Abstract

Polysiloxanes are unique polymers used in medicine and materials science and are ideal for various modifications. Classic functionalization methods involve a covalent approach, but finer tuning of the properties of the final polymers can also be achieved through sub-sequent noncovalent modifications. This study introduces a fundamentally new approach to polysiloxane functionalization by incorporating cooperative noncovalent interaction centers: selenium-based chalcogen bonding donors and polyfluoroaromatic π-hole acceptors into a single polymer platform. We developed an efficient nucleophilic substitution strategy using poly((3-chloropropyl)methylsiloxane) as a platform for introducing Se-containing groups with polyfluoroaromatic substituents. Three synthetic approaches were evaluated; only direct modification of Cl-PMS-2 proved successful, avoiding catalyst poisoning and crosslinking issues. The optimized methodology utilizes mild conditions and achieved high substitution degrees (74–98%) with isolated yields of 60–79%. Comprehensive characterization using 1H, 13C, 19F, 77Se, and 29Si NMR, TGA, and contact angle measurements revealed significantly enhanced properties. Modified polysiloxanes demonstrated improved thermal stability (up to 37 °C higher decomposition temperatures, 50–60 °C shifts in DTG maxima) and increased hydrophobicity (water contact angles from 69° to 102°). These systems potentially enable chalcogen bonding and arene–perfluoroarene interactions, providing foundations for materials with applications in biomedicine, electronics, and protective coatings. This dual-functionality approach opens pathways toward adaptive materials whose properties can be tuned through supramolecular modification while maintaining the inherent advantages of polysiloxane platforms—flexibility, biocompatibility, and chemical inertness.