| A novel one-pot polymerization and side-chain multifunctionalization system hasbeen developed, which combines controlled polymerization and pendent groupmodification in just one-pot style, thus generating multifunctional polymers in one step.Compared with traditional techniques (step-by-step approach and post-modificationmethod), one-pot strategy has many intrinsic advantages: time-saving, atom-economic,green and highly efficient, because it avoids tedious separation and purification ofintermediates.However, not all organic reactions and polymerization could be easily cooperatedin one pot. In order to perform well in one system, the side-chain modificationreactions should be fast, highly efficient and suitable for polymerization, and thepolymerization should be well-controlled and adjustable. In this report, reversibleaddition-fragmentation chain transfer polymerization (RAFT polymerization) takes therole of polymerization for its general utility and great tolerance of other components,while enzymatic transesterification has been chosen to modify the side group ofpolymers as it is widely considered to be effective and highly selective.After the system feasibility study and the optimization of reaction conditions, theone-pot system combining RAFT polymerization and enzymatic transesterification hasbeen successfully developed. Both reactions cooperated well without interference, thusgenerating well-defined functionalized homopolymers with high efficiency. Themolecular weight of product polymers was controllable and the polydispersity indexwas very low. What’s more, various primary alcohols could work well in this system,proving that it might be a universal methodology for functional polymer synthesis. Andall the enzyme used maintained high activity after participating in the one-potpolymerization, indicating that this strategy is environmentally friendly.According to those advantages stated above, one-pot RAFT polymerization andenzymatic transesterification is quite suitable for exquisite polymer synthesis, whichhas been regarded as an arduous task by traditional methodologies. Chiral polymers,for instance, could be easily prepared by this one-pot system. Specifically, racemicalcohols were introduced as substrates for enzymatic kinetic resolution, thus generating chiral monomers in-situ, which participated in the subsequent RAFT polymerization.In addition, the impact of reaction conditions, such as temperature, solvents and theamount of enzyme used in this system, have been systematically studied, to investigatetheir roles in the one-pot process. Polymers composed of chiral monomers prepared bystep-by-step synthetic approach were prepared as well for control study. |
