(115c) Towards Tailor-Made Automatically Controlled Compositional Gradient Copolymers

The technique called Automatic Continuous Online Monitoring of Polymerization Reactions (ACOMP) allows real time monitoring and control of key parameters of a polymer synthesis. ACOMP is the ideal process control system platform to continuously feed data into a closed loop feedback controller to produce polymers of desired specifications, such as fixed molecular weight and copolymer composition. Because the ACOMP system provides continuous, direct, real time measurements of molecular weight, monomer concentrations, and compositions a controller was developed to operate without recourse to a detailed kinetic model or reactivity ratios, making it theoretically suitable to any system. Copolymers of acrylamide (Am) and sodium styrene sulfonate (SS) were obtained following different trajectories for both molecular weight and composition by free radical polymerization in aqueous medium. This talk focuses on previous successful work using this controller and presents the next steps towards tailor-made compositional gradient copolymers. Through coupling with reversible addition-fragmentation chain-transfer polymerization (RAFT), changes in monomer concentration in the reactor led by the controller are directly reflected on each individual macromolecule, allowing for tailoring the gradient composition of the final product. Gradient copolymers show unique behavior in bulk and in solution due to the gradual change in composition within the polymer chains making them interesting for a wide range of applications, such as damping materials, compatibility enhancers in polymer blends, emulsion stabilizers, drug delivery systems and even photovoltaic units. The use of this in-house built controller with RAFT will allow for producing copolymers with whatever desired compositional gradient distribution in an efficient and straightforward manner.