The role of biomolecular building blocks on the cohesion of biomatter plastics

Unaltered biological matter (biomatter) can be harnessed to fabricate cohesive, sustainable bioplastics. However, controlling the material properties of these bioplastics is challenging, as the contributions of different macromolecular building blocks to processability and performance are unknown. To deconvolute the roles of different classes of biomolecules, we developed experimental and computational methods to construct and analyze biomatter analogs composed of carbohydrates, proteins, and lipids. These analogs are intended to improve fundamental understanding of biomatter plastics. Spectroscopic analyses of biomatter analogs suggest that cohesion depends on protein aggregation during thermomechanical processing. Molecular dynamics simulations confirm that alterations to protein conformation and hydrogen bonding are likely the primary mechanisms underlying the formation of a cohesive, proteinaceous matrix. Simulations also corroborate experimental measurements highlighting the importance of hydrogen bonding and self-assembly between specific, small-molecule constituents. These conclusions may enable the engineering of next-generation biomatter plastics with improved performance.