Tailoring of the molecular weight distribution by nonstationary (free radical) polymerization conditions

The choice of quenched instationary polymerization (QUIP) conditions will influence the shape and the moments of the polymers formed. As the quench reaction deactivates all radicals present at a given time, the total molecular weight distribution will always be a superposition of the (quenched) radical chain length distribution (RCLD) and the polymer chain length distribution (PCLD). Model calculations were carried out taking into account the different types of initiation conditions. In principle, distributions with extremely low polydispersities (Poisson-type) can be obtained as well as broad structured or non-structured distributions. Polymerization conditions will also determine whether the radical spectrum dominates a certain region of the distribution.