This thesis explores the design of multistage polymer networks to separate desirable enduse properties from those optimal for processing purposes. Sequential control of light, heat, or other external stimuli enables this feat. Additional control is provided by spatial patterning of light as employed in the fields of holography, mechanophotopatterning, and volumetric additive manufacturing. Therefore, by comparing mechanical, geometrical, and optical properties throughout the stages of production, this work demonstrates the benefit of a multistep approach.

The first part of this thesis pertains to the implementation of a 3-stage network to prepare glassy holographic photopolymers. In Chapter 3, the combination of a urethane matrix, acrylate writing monomer, and a latent rigid core epoxide, enabled holographic writing in the desired rubbery state. Subsequent epoxide activation resulted in a final T_g of 101 °C with a storage modulus on the order of GPa at ambient temperature. A corresponding diffraction efficiency of 89% with 0.3% haze was achieved in 50 µm thin films. 

The second part of this thesis focuses on the use of a dual-cure approach to spatially fix the topography of mechanophotopatterned films. In Chapter 4, this work prevented further topographical evolution via allyl sulfide dynamics by increasing the crosslinking density and T_g following patterning. The inclusion of 65 wt% bisphenol A diglycidyl ether mitigated the residual dynamics upon homopolymerization with a thermally latent acid. Surface features fixed by this cure remain within 1% of their original height after extended light exposure. Furthermore, in Chapter 5, the dual-cure system was employed to provide spatially fixed and consistent results to validate a computational model.

The final part of this thesis employs a multistage approach to prepare a negative photoresist for VAM. In Chapter 6, a polyurethane scaffold with degradable thioester linkages was combined with a variety of low-viscosity methacrylate writing monomers. Therefore, this scaffold provides accessibility to these monomers, and the mechanical properties they provide, without object settling due to gravity during the printing process. The scaffolding was later removed by aminolysis with little damage to the printed parts or their mechanical properties. Further, added inhibitor and real-time chemical and mechanical monitoring enabled high resolution printing with consistent timing.