We used five distinct acrylic prepolymers divided into two main categories: (i) structures with different chain lengths but the same functionalities per unit mass, i.e., S-6OH (short chain with Mw≈ 1382 g/mol), M-6OH (medium chain with Mw ≈ 2765 g/mol), and L-6OH (long chain with Mw ≈ 5552 g/mol), and (ii) structures with the same chain length but variable functionality, i.e., all medium chain length, M-6OH (high OH functionality:142 mg KOH/g resin), M-4OH (medium OH functionality: 103 mg KOH/g resin), and M-3OH (low OH functionality: 83 mg KOH/g resin). All precursors are cross-linked with hexa(methoxymethyl)melamine (HMMM) in a 1:1.2 molar ratio of reactive groups, with excess melamine used to align with common industry practice (see the structures in Figure ). Table summarizes the details of five different systems. The coarsegrained prepolymer models and the cross-linker were initially energy-minimized, mixed, and equilibrated. A snapshot from the equilibrated model (Figure ) and the melaminemelamine radial distribution function (RDFmel-mel), excluding intra-molecular interactions, show small local melamine aggregates (Figure ), which is an expected occurrence in acrylic-melamine mixtures. The structure and properties of the polymers are investigated during the curing process (detailed in SI section S2.4). Note that, in parallel to the simulation study, we experimentally synthesized a pre-polymer similar to L-6OH model (see Figure ) and cross-linked it with HMMM, characterized through NMR, GPC, FTIR, and DMA measurements at various curing times. Detailed information on the materials used, the synthesis process, and the preparation and characterization of freestanding films (Figure ) is provided in SI section S1, and CG parametrization is explained in SI section S2.1-S2.3. The radial distribution function of melamine-melamine before initiating the cross-linking reaction (intra-molecular interactions were excluded).