# Synthesis of Vinyl-Containing MQ Copolymers in Active Medium

## TL;DR

This paper presents a new chlorine-free method to synthesize vinyl-containing MQ copolymers with controlled properties and high thermal stability.

## Contribution

A controlled, chlorine-free synthesis method for structurally tunable MVinMQ copolymers is introduced.

## Key findings

- Copolymer architecture was precisely controlled with increasing Q-unit fraction affecting hydroxyl content and molecular weight.
- MVinMQ copolymers showed high thermal stability with 5% mass loss above 295 °C in air and 365 °C in argon.
- Fractionation data supported a molecular composite model with an inorganic core and organic shell.

## Abstract

MQ copolymers, consisting of monofunctional (M) and tetrafunctional (Q) siloxane units, are versatile materials used as additives, adhesives, and in composite materials. Functional groups, such as vinyl substituents, in M-units allow for the tailoring of properties for specific applications. This study aimed to synthesize vinyl-containing MQ copolymers (MVinMQ) via a controlled, chlorine-free method to explore the regulation of their composition and properties. The results demonstrated precise control over the copolymer architecture, with hydroxyl content and molecular weight increasing alongside the Q-unit fraction. All obtained copolymers exhibited high thermal stability, with 5% mass loss occurring above 295 °C in air and 365 °C in argon. Fractionation data supported a molecular composite model consisting of an inorganic core and an organic shell. Polycondensation in an active medium is an effective method for the directed synthesis of structurally tunable MVinMQ copolymers, offering a versatile platform for developing functional hybrid materials, modifiers, and cross-linking agents.