| 초록 |
A mechanochemical polymerization of lactide is developed using ball milling. Mechanical energy from the collisions between the balls and the vessel efficiently promoted an organic-base-mediated metal- and solvent-free solid-state polymerization. Investigations on the parameters of the ball-milling synthesis revealed that the degree of lactide ring-opening polymerization could be modulated by the ball-milling time, vibration frequency, mass of the ball media, and liquid-assisted grinding. Especially, liquid-assisted grinding was found to be an important factor for achieving a high degree of mechanochemical polymerization. While polymer-chain scission from the strong collision energy prevented a mechanical-force-driven high-molecular-weight polymer synthesis, the addition of only a small amount of liquid provided a sufficient energy dissipation. Thus, poly(lactic acid) with a molecular weight over 1 x 105 g/mol was successfully obtained by the green mechanochemical approach. |
