Mothe, S. R., Kanaujia, P., Oh, A. B. Y., Ang, P., & Thoniyot, P. (2023). PVA free-radical diblock copolymer for nanoencapsulation with enhanced biodegradability in the environment. European Polymer Journal, 196, 112287. https://doi.org/10.1016/j.eurpolymj.2023.112287
Abstract:
The synthesis of readily biodegradable amphiphilic polyvinyl alcohol diblock copolymers (poly(VA-b-MDO)) was achieved through the combination of radical ring-opening polymerization (rROP) and reversible addition-fragmentation chain-transfer (RAFT)-living radical polymerization using 2-methylene-1,3-dioxepane (MDO) and vinyl acetate (VAc) monomers in three steps. The chemistry features solvent-free conditions (bulk polymerization) and subsequent deprotection of the acetyl group under mild conditions. With this optimized method, various lengths of poly(VA) and poly(MDO) in poly(VA-b-MDO) were synthesized by controlling the molecular weight distribution of both blocks. The self-assembly of diblock copolymers to nanoparticles with narrow size distribution and subsequent encapsulation of personal care and pharma active ingredients (e.g., curcumin and fenofibrate) and their controlled release were investigated. In vitro release experiments demonstrated that encapsulated nanoparticles release the actives at a slow and consistent rate compared to free actives. Stability experiments showed that the particle size distribution and purity of curcumin and fenofibrate remained unchanged after being exposed to light for ten months. More importantly, our environmental biodegradability studies revealed that the degradable poly(VA-b-MDO) (6b), consisting of 35 mol% poly(VA) and 65 mol% poly (MDO) blocks, achieves a biodegradability of 78% in 28 days. This is owing to the higher mole ratio of degradable polyester units in the polymer backbone as compared to poly(VA-b-MDO) (6a), which contains 64 mol% poly(VA) and 36 mol% poly(MDO) blocks (33% in 28 days). Our results provide insights into the potential applicability of these polymers in personal care and pharma products where biodegradability is a crucial factor. By developing a sustainable methodology from synthesis to application, our work helps to harness the potential of biodegradable diblock copolymers in the consumer care and medical fields.
License type:
Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)
Funding Info:
This research / project is supported by the Agency for Science, Technology and Research (A*STAR) - Specialty Chemicals AME IAF-PP Programme Grant
Grant Reference no. : A1786a0025
This research / project is supported by the Agency for Science, Technology and Research (A*STAR) - Specialty Chemicals AME IAF-PP Programme Grant
Grant Reference no. : A20G1a0046