Structural applications require robust mechanical properties (strength, modulus, toughness) and environmental resistance (heat, light, moisture). We try to improve the structural performance of polymeric materials by controlling the chemical and physical structures (nano/meso). For example: modifying the network structure of crosslinked polymers to improve rate-dependent behavior; blending renewable biomass with conventional polymers like polyolefins to create mechanically robust, sustainable composites for automobiles; functionalizing inorganic layered materials with dynamic covalent bonds facilitates in-situ polymerization and photo-controllable reversible functionalization. Current and future work focuses on the development of sustainable, multifunctional polymeric composites for advanced structures and other applications.