Transition state searches have been performed on model coarse-grained polymer systems, and the results compared to those of an antiplasticized polymer system, which have been previously shown to be fragile and strong glass-forming systems, respectively. It was found that the antiplasticizing molecules reduce the energy barriers for relaxation compared to the pure polymer, thereby explaining the lower characteristic temperatures of glass-formation found previously. We examined the tendency of our bulk systems to move cooperatively as they moved through transitions of energy barriers, and we found that larger cooperatively rearranging regions are required to overcome larger energy barriers.Additionally, we study the effects of confinement on the energy barriers in each system. It is found that confinement makes the energy barriers substantially smaller in the pure polymer, while it has little effect on the energy barriers in the antiplasticized system.
Citation: Physical Review E (Statistical, Nonlinear, and Soft Matter Physics)
Pub Type: Journals
antiplasticer additives, film imprinting, fragility, glass transition, nanoparticles, polymer melt, shear modulus, voronoi volume