Modeling of Free-Radical Polymerization under Periodic Photoinitiation

• Published in: Polymer science. Series B Vol. 64; no. 1; pp. 78 - 87
• Main Authors: Roshchin, D. E., Patlazhan, S. A., Berlin, A. A.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.02.2022; Springer Nature B.V
• Subjects: Asymptotic methods; Chemistry; Chemistry and Materials Science; Degree of polymerization; Free radical polymerization; Free radicals; Mass distribution; Method of moments; Polydispersity; Polymer Sciences; Polymerization; Radicals; Theory and Simulation
• ISSN: 1560-0904; 1555-6123
• DOI: 10.1134/S1560090422010067

— Free-radical polymerization with periodic photoinitiation profile at low conversion degree has been modeled. The method of moments used for the calculations has been able to adequately reproduce the asymptotic solutions at low and high initiation frequency, which has confirmed the validity of the obtained results. The effect of the initiation frequency over its wide range on the characteristics of the obtained polymer and depth of polymerization has been studied. The evolution of the number-average degree of polymerization and the polydispersity index has been investigated. Duration of the induction period, during which the amplitude of the molecular mass oscillation is changed over time has been found as a function of the initiation frequency. It has been stated that the polydispersity index is significantly increased if the photoinitiation frequency is below certain threshold, pointing at the polymodality of the molecular mass distribution. The optimal range of the frequency to determine the propagation rate constant taking advantage of the periodic photoinitiation has been determined.