ATOMISTIC MODELING OF AMORPHOUS AROMATIC POLYBENZOXAZOLES

Atomistic models of two different fluorinated polybenzoxazoles, 6F-PBO and 3F-PBO, were used to simulate the amorphous structures of these p olymers. Molecular mechanics and molecular dynamics techniques were ut ilized to relax the independent structures from an initial high-energy system. The relaxed model structures showed 6F-PBOs to be more coiled relative to 3F-PBO. Conformational grid search was performed on each of the repeat units to analyze the local structure of the two polymeri c backbones. The torsional angles corresponding to energy minima and r otational barrier were found to vary between the 6F and 3F structure d ue to differences in the pendant group at the C-alpha carbon atom. The Hildebrand solubility parameters and elastic constants for the two di fferent polymers were estimated from simulation. 3F-PBO is predicted t o possess a higher solubility parameter and higher moduli compared to the GF-PBO.