Molecular Simulation of Semicrystalline Polymers

Polymers crystallized in the bulk are never completely crystalline due to their long chain nature and subsequent entanglements. Hence, even the most crystallizable polymers show both crystalline and amorphous domains below the melting temperature . We are studying semicrystalline polymers, especially the interelamellar domain, using Monte Carlo simulations under conditions of metastability. Various properties including thermodynamics, structure and elastic mechanical properties have been already characterized for several years. (See the publication list.) Currently, we are focusing on the plastic deformation of the interlamellar phase employing Monte Carlo, molecular dynamics and primitive path analysis (PPA). Chains of the interlamellar phase are categorized into tails, loops and bridges by their connectivity relation to crystalline lamellae.

It is believed that entanglements as well as bridge chains in the interlamellar phase play a critical role in determining mechanical properties of the semicrystalline polymers. Therefore, tracking changes of topological state through entanglements as well as connectivity to the crystal gives important clues for understanding the plastic deformation of the semicrystalline polymers. PPA using the Z-algorithm of Kröger et al provides a measure of the entanglement topology, by which we expect that transitions in topological state can be observed during the plastic deformation process.