Figure 1.

a) Photopolymerization of DCPD in the solid state converts a plastic crystal into an amorphous crosslinked network. b) Plastic crystals are a distinct crystalline phase with plasticity due to weak intermolecular forces which allow for molecular rotational degrees of freedom, in contrast to ordered organic crystalline phases, with both translational and rotational order, leading to brittle crystal phases. c) Heating ramp of DCPD reveals a melting point near ambient of 32 °C, with a transition from waxy solid to low viscosity liquid demonstrated in the inset images. d) Optical micrographs showing recrystallization of DCPD from liquid state at ambient conditions. DCPD plastic crystalline phases demonstrate long‐range order, and pack in a regular cellular fashion.