Gelation dynamics in elastomers with branched architecture

Elastomers with non-linear polymer architectures have drawn significant interest due to their soft, solvent free nature. Mechanical properties of such gels are highly modular through control of the molecular architecture. The competition between elastically effective crosslinkers and dangling branched side chains creates an environment where precise control of these architectural components during processing is challenging. Here, we address the impact of side chain grafting on structure formation during curing in soft elastomers. The chain dynamics and relaxation processes are resolved by transient rheological techniques. Network formation during curing is compared to the gelation of linear chain elastomer analogs, of which the dynamics are well established. We address the impact of the cure process on the gel fraction and incorporation of various chain types, which further modulates the final mechanical properties. This work illustrates the importance of understanding and controlling structure in real time to achieve predictable properties.