Design and Control of Polymeric Network Architectures Based on Network Dimension Theory

Abstract

A new design policy to synthesize nanogel molecules having desired dimensions under unperturbed state is proposed. Miniemulsion copolymerization of vinyl and divinyl monomers, both conventional free-radical polymerization and ideal living polymerization, is used to illustrate the method. For the network formation dynamics, the newly proposed model that takes into account the size and structure dependence of cross-linking/cyclization reactions is employed. The master curve relationship that indicates the maximum average dimensions for randomly cross-linked networks is used as a guideline and the network dimension is controlled by the magnitude of network maturity index NMI, which is the average number of cycle rank per primary chain. By appropriately sizing the NMI, it is possible to synthesize network polymers with dimensions equal to or greater than the maximum dimensions achievable with a homogeneous, randomly cross-linked network polymer of the same cycle rank and molecular weight. The current strategy of designing and controlling 3D size is applicable regardless of the reaction mechanism of network formation and will also be applied to the synthesis of macro-gels.