showed a trendp < 0.001
The variation in the modulus of toughness, M T , determined as the total area under the tensile stress–strain curve before film fracture, 25 showed a trend opposite to the variation in E for the EQU, PAR, and ISO films, with an overall decrease of ∼78% from ISO to EQU films ( p < 0.001, EQU = PAR < ISO).