Sustainable elastomers derived from cellulose, rosin and fatty acid by a combination of "graft from" RAFT and isocyanate chemistry.

Utilization of natural sustainable feedstock to fabricate polymers has attracted remarkable attention. In this work, we reported a strategy to prepare a series of grafted copolymers from rosin, fatty acids and ethyl cellulose. The process involved the preparation of EC-based macro-RAFT agent through a simple esterification reaction, followed by a "grafting from" reversible addition-fragmentation chain transfer polymerization (RAFT) of DAGMA (derived from rosin) and LMA (derived from fatty acid) to achieve a class of EC-g-P(DAGMA-co-LMA) graft copolymers with a tunable Tg tuned by the DAGMA/LMA molar ratio. Then, hexamethylene diisocyanate (HDI) was used to crosslink these graft copolymers. The mechanical and dynamic thermo-mechanical properties of tests showed that elastic recovery values of copolymers were enhanced to 90%, as compared to the un-crosslinked samples. Additionally, all these polymers showed an excellent UV absorption performance. This study provides a facile way to fabricate biobased elastomeric materials with improved mechanical properties.