Search

The preparation of forced gradient polymers has received considerable attention using batch reactors, while the preparation of usable quantities of forced gradient copolymers using continuous flow reactors has been hampered by the need to vary the composition of the monomer feedstock continuously during the reaction. A reactor that allows for addition of a monomer feedstock continuously at all points along the length of the reactor tubing allows for the preparation of forced gradient copolymers in continuous flow reactors, allowing for the scale-up and bulk preparation of these polymers. This study reports here the initial investigation of preparing forced gradient copolymers using the reversible addition-fragmentation chain transfer methodology in tube-in-tube continuous flow reactors. [ABSTRACT FROM AUTHOR]

A continuous flow process for the radical-induced end-group removal of polymers made by a RAFT process is described. A series of different monomers, including acrylamides, methacrylate, and styrene are polymerized at 70-100 °C using various different RAFT agents, solvents, and radical initiators. The subsequent end group removal process is carried out in a steel tube flow reactor system at 100 °C in organic solvents or water. After reaction, the polymers exhibit low polydispersities between 1.03 and 1.19, and average molecular weights between 7500 and 22 800 g · mol−1. This continuous flow approach provides a facile alternative scale-up route to conventional batch operation and can be integrated into a sequential flow process consisting of RAFT polymerization followed by post-treatment. [ABSTRACT FROM AUTHOR]