Methods of forming nanoporous materials are described herein that include forming a polymer network with a chemically removable portion. The chemically removable portion may be polycarbonate polymer that is removable on application of heat or exposure to a base, or a polyhexahydrotriazine (PHT) or polyhemiaminal (PHA) polymer that is removable on exposure to an acid. The method generally includes forming a reaction mixture comprising a formaldehyde, a solvent, a primary aromatic diamine, and a diamine having a primary amino group and a secondary amino group, the secondary amino group having a base-reactive substituent, and heating the reaction mixture to a temperature of between about 50 degC and about 150 degC to form a polymer. Removing any portion of the polymer results in formation of nanoscopic pores as polymer chains are decomposed, leaving pores in the polymer matrix.

A biodegradable crosslinked polymer which is a reaction product of a polymer having aldehyde-reactive functional groups and a polyaldehyde, wherein the polymer having aldehyde-reactive functional groups comprises a biodegradable structure or the polyaldehyde comprises a biodegradable structure.