The “Nascent” Nature of High-Molecular-Weight Polymers: Molecular Dynamics Simulations of Concurrent Polymerization and Crystallization

We investigate the fundamental features that define a polymer as “nascent” by developing and analyzing a new coarse-grained molecular dynamics framework to simulate linear high-molecular-weight nascent polymers. Our model captures the simultaneous polymerization and crystallization processes that drive the formation of long chains ( ≈ 5.3 × 1 0 5 ⁡ g ⁡ m o l − 1 ), which are characterized by a lower entanglement density and a higher crystalline ratio than their counterparts synthesized from the melt state. By tuning the chain growth kinetics through the simulation parameters, we further demonstrate how the resulting semicrystalline morphology can be tailored. We eventually identify the entanglement density and the crystalline ratio as key structural descriptors to quantify the polymer nascent character, or “ nascentness ”, and propose for the first time a formal definition of this concept.