Understanding the Origin of the Low Cure Shrinkage of Polybenzoxazine Resin by Computational Simulation

Thermoset resin-based composite materials are widely used in the aerospace industry, mainly because of their high stiffness-to-weight and strength-to-weight ratios. A major issue with use thermoset resins fiber composites is process-induced residual stresses that formed from resin chemical shrinkage during curing process. These within material ultimately result reduced durability deformations final product. Polybenzoxazine (PBZ) polymer have demonstrated near-zero volumetric Although low PBZ promising terms stresses, little known about physical causes. In this work, molecular dynamics (MD) simulations performed a reactive force field to predict properties (gelation point, evolution network, mass density, shrinkage) mechanical (bulk modulus, shear Young’s Poisson’s ratio, yield strength) as function cross-linking density thermal (glass transition temperature). The MD modeling procedure validated herein using experimental measurements modeled resin. results study provide understanding zero-shrinkage phenomenon PBZ. This information also critical input future process efforts for composites.