Non-Covalent Glassy Networks for Photocurable Materials: Physical Crosslinks, Relaxation, Reprocessability and Service Limits

Non-covalent networks are often associated with soft, rapidly relaxing materials, yet sufficiently strong and slow supramolecular associations can produce glass-like response with high modulus or compressive strength while retaining recoverability. Published supramolecular polymer glasses and slow-dissociative crosslink networks demonstrate that bond lifetime can shift the balance between stiffness, damage recovery and flow. [1-3] Translating these principles into photocurable materials creates a hybrid design problem: covalent photopolymerisation may fix geometry while non-covalent interactions control secondary stiffness, relaxation or reprocessability. ER-420 separates physical crosslink density from covalent conversion, defines time-temperature dependent qualification, and warns against equating short-time modulus with service stability. A material may behave as a glass on a tensile-test timescale yet creep, heal or flow over longer periods. Qualification therefore requires relaxation spectra, creep, recovery, thermal history and repeated reprocessing evidence at the intended use timescale.