Facile Modification of Propiolated Castor Oil via Nucleophilic Thiol‐Yne Click Reactions

Abstract

The combination of modern click protocols and bio‐based building blocks is a great step towards energy‐efficient, sustainable, and tailorable polymer production. Herein, we chose thiol‐Michael addition (thiol‐yne) reactions from the toolbox of click chemistry protocols and used propiolated castor oil (PCO), a vegetable oil derivative, as the bio‐based building block for the facile functionalization of PCO with various thiols. In addition to the functionalization of PCO, hyperbranched and crosslinked polymers were also prepared. The thiol‐yne click functionalization reactions of the PCO were conducted at room temperature within 5 minutes and in the presence of an organic catalyst. The modifications were conducted in 2‐MeTHF. The yields were found to change between 80–99% depending on the type of the thiol compound. The effect of various organic catalysts was investigated, and 1,8‐diazabicyclo(5.4.0)undec‐7‐ene (DBU) was found to be the most effective catalyst for the thiol‐yne modification reactions. The hyperbranched polymer reached 23.8 kDa (Mw) within 5 minutes. The thermosets displayed low glass transition temperatures (Tgs) between ‐46 °C and ‐26 °C. The findings of this paper open up new horizons for polymer researchers who work in the field of sustainable polymers and click chemistry and the presented idea here is appealing because it offers a potential strategy for fast, reliable, modular, and functional macromolecule preparation from renewable vegetable oils.This article is protected by copyright. All rights reserved