A Study of Mechanical Behavior of Ethylene Vinyl Alcohol (EVOH) in Contrast to Poly(Lactic acid) (PLA) and Polypropylene (PP)*

Semicrystalline polymers are usually brittle below their T_g, with PLA and PP being well-known examples. Based on our recent understanding of ductility in glassy polymers¹, we have recently demonstrated how to acquire a semi-crystalline PLA that is super tough, optically clear and rigid at 120 ^oC, well above its T_g.² The interplay between crystallization and vitrification is further explored based on the example of EVOH that appears to contrast sharply with PLA in all aspects, with an emphasis on the effect of pre-deformation.

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2. Razavi, M.; Wang, S.-Q. Why Is Crystalline Poly(lactic acid) Brittle at Room Temperature? Macromolecules 2019, 52 (14), 5429-5441 DOI: 10.1021/acs.macromol.9b00595.