# Solution and precipitation based radical polymerization of renewable vinyl lactones in renewable solvents

## TL;DR

This paper presents a green method to make sustainable polymers from renewable materials using eco-friendly solvents and purification techniques.

## Contribution

A scalable, low-impact polymerization route using renewable vinyl lactones and solvents is introduced.

## Key findings

- Precipitation polymerization enables efficient recovery and solvent reuse.
- Polymers show high optical transparency with visible light transmittance over 96%.
- Glass transition temperatures of 99 °C (polyMeGVL) and 94 °C (polyMeGBL) were achieved.

## Abstract

Sustainable polymers are essential to reducing the environmental impact of conventional plastics. While the use of renewable feedstocks plays a significant role, the adoption of green processes, including sustainable solvent selection and efficient polymer purification, is equally essential. This study presents a green synthesis route for polymers based on two renewable vinyl lactone monomers: α-methylene-γ-valerolactone (MeGVL) and α-methylene-γ-butyrolactone (MeGBL). Polymerization was performed in renewable solvents as Cyrene®, γ-valerolactone, and 2-methyltetrahydrofuran via solution and in biobased alcohols through precipitation methods. While solution polymerization requires additional purification step through polymer precipitation, precipitation polymerization enables efficient polymer recovery and solvent reuse. The resulting polymers made via precipitation polymerization exhibit properties with glass transition temperatures of 99 °C (polyMeGVL) and 94 °C (polyMeGBL), and visible light transmittance over 96% between 450–700 nm of both polymer films of thickness around 100 μm. Water contact angles of the films were 62° for polyMeGVL and 51° for polyMeGBL showing difference despite having a similar chemical composition. These results highlight a scalable, low-impact pathway for producing commodity polymers entirely from renewable resources.

Acrylic-type renewable vinyl lactone polymers are made via radical polymerization in bio-based solvents. A precipitation route provides high-purity materials with high optical transparency, highlighting a scalable path for green polymer production.