Energy-efficient manufacturing of polymers with tunable mechanical properties by frontal ring-opening metathesis polymerization

Frontal polymerization (FP) is a process in which the heat generated by the self-reaction transforms monomers to cured polymers. Here, in order to improve the flexibility of polydicyclopentadiene, comonomers (norbornene-terminated polyether, ND-230,400,2000) are designed and synthesized, which can copolymerize with dicyclopentadiene (DCPD) by FP. The polymers (ND) prepared by ND-2000 and DCPD have tunable mechanical properties, from thermosets to elastomers. Specifically, the breaking elongation of the polymers can be varied 69-fold, from 6.1% to 423.4% by controlling the proportion of ND-2000. Among them, ND polymer with 50 wt% ND-2000 has good elastic behavior without yield. And, the reaction mixture solutions of DCPD and ND-2000 have the characteristics of controllable gel time and shear thinning, which make it have the potential of application in additive manufacturing.