Load-bearing entanglements in polymer glasses.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 34533993.
- Also identified by DOI 10.1126/sciadv.abg9763 and PMC identifier 8448454.
- Licence recorded as CC BY-NC.
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Abstract
Through a combined approach of experiment and simulation, this study quantifies the role of entanglements in determining the mechanical properties of glassy polymer blends. Uniaxial extension experiments on 100-nm films containing a bidisperse mixture of polystyrene enable quantitative comparison with molecular dynamics (MD) simulations of a coarse-grained model for polymer glasses, where the bidisperse blends allow us to systematically tune the entanglement density of both systems. In the MD simulations, we demonstrate that not all entanglements carry substantial load at large deformation, and our analysis allows the development of a model to describe the number of effective, load-bearing entanglements per chain as a function of blend ratio. The film strength measured experimentally and the simulated film toughness are quantitatively described by a model that only accounts for load-bearing entanglements.