Kinetic model for the gelation process in the synthesis of soluble poly(p-phenylene vinylene) derivatives via Gilch route

Soluble PPVs are important optoelectronic polymers, which usually synthesized via the Gilch route. However, gelation or microgelation has been a severe drawback which leads to the product loss of solubility and the actual gelation mechanism has not been systematically investigated. Based on the assumption that gelation arises from the interchain substitutional byreactions, we establish a kinetic model to depict the gelation process in this paper. It gives out various factors that influence the gelation process, such as base concentration, the rate ratio of the conjugation formation process to the interchain substitutional byreactions. These theoretical conclusions can account for the experimental results of various modified Gilch routes.