Pulsed polymerization of acrylate monomers using electron beam. Conditions for achieving single-phase heterogeneous polymerization

The heterogeneous nature of energy deposition by ionizing radiation can be used to advantage by pulsing an electron beam at low dose per pulse and high pulse rates. Track overlap is avoided for a short period of time, sufficient to allow an essentially heterogeneous polymerization to take place. High pulse rates appear to maintain this advantage by terminating the incipient homogeneous kinetics while re-initiating the heterogeneous kinetics. Polymerization by this method shortens the residence time necessary for full conversion but beyond 50% conversion, there may no longer be any advantage in a diffusion-limited system. Lower temperature also helps to reduce termination in the early phase of polymerization.