Study of cooperative relaxation characteristics of a simultaneously nanoparticle- and photopolymerization-Induced dynamically quaternary photopolymeric network

Herein, a toughed dynamically-quaternary photopolymeric material was designed through photopolymerization and the polymeric nanoparticle incorporation process. In order for availability of such reinforced system, a low content of poly (styrene-co-acrylonitrile) (SAN) nanoparticle was incorporated into an acrylate-based photopolymerization-induced dynamically-binary photopolymeric network. The dynamic transformation from a binary form to a quaternary form with addition of only 1 wt% of the SAN nanoparticles was demonstrated through the dynamic mechanical results. Relaxation characteristics of all four dynamic characteristic domains including microgel particle, the soft matrix, that of the SAN nanoparticle, and interfacial loose layer were studied. The relaxation characteristic length (ξ(Tg)) of the microgel particle, the soft matrix, the SAN nanoparticle, and the interfacial loose layer were estimated to be 2.24 nm, 2.55 nm, 2.2 nm, and 2.66 nm, respectively. The dynamic fragility index (m) of the SAN and the microgel particle were computed to be 133 and 16, respectively.