livingpolymerointitekniikoiden
Living polymerization techniques are a class of polymer chain growth methods that allow for precise control over polymer architecture, molecular weight, and low polydispersity. These techniques are characterized by the absence of irreversible chain termination and chain transfer reactions. This means that the active chain ends remain capable of further propagation indefinitely, or until deliberately deactivated. The key feature of living polymerization is that all polymer chains initiated grow simultaneously and at approximately the same rate. This controlled growth leads to polymers with very narrow molecular weight distributions, often expressed by a dispersity index (Đ) close to 1.0. Furthermore, living polymerization enables the synthesis of complex polymer structures such as block copolymers, star polymers, and grafts by sequential addition of different monomers or by using multi-functional initiators. Common examples of living polymerization include anionic polymerization, cationic polymerization, atom transfer radical polymerization (ATRP), reversible addition-fragmentation chain transfer (RAFT) polymerization, and ring-opening metathesis polymerization (ROMP). These advanced polymerization methods are crucial for the development of advanced materials with tailored properties for applications in areas like drug delivery, advanced coatings, and nanotechnology.