Relaxation-enhanced polymer nanocomposites induced by bound polymer loops on the particle surfaces
Quanyin Xu, Huaiyuan Qu, Zhenghao Wu, Zhenyun Zhao, Sisi Ge, Jintian Luo, Biao Zuo
Abstract
Polymer nanocomposites (PNCs) benefit from the enhanced properties originating from the synergistic effects of nanoparticles (NPs) and a polymer matrix. However, the incorporation of NPs slows PNC relaxation, and particularly at high-particle-loading, the PNC melts become non-flowing because the interfacially adsorbed polymers bridge the particles, generating a kinetically quasi-permanent particle network. Herein, by introduction of bound polymer loops on the NP surfaces, we molecularly design a relaxation-enhanced PNC, where interfacial polymers adhering to the NP surfaces freely relaxed, enabling formation of a dynamic, loose particle network that facilitates flow of the PNC melts. The resultant molten high-NP-loading composites maintain fluid-like and low-viscosity dynamics, while the corresponding glassy materials possess enhanced toughness and strength. Thus, the demonstrated principle of preparing relaxation-enhanced PNCs by optimizing the way by which polymers are attached to the filler surface represents the state-of-the-art strategy for overcoming the tradeoff between the processability and mechanical performance of PNCs. Incorporation of nanoparticles into polymer nanocomposites (PNC) slows PNC relaxation and particularly, PNC melts become nonflowing at high-particle-loading. Here the authors introduce bound polymer loops on the NP surfaces and design a relaxation-enhanced PNC with a loose particle network that facilitates flow of the PNC melts.