RENEWABLE POLYESTER FILM HAVING A LOW MODULUS AND HIGH TENSILE ELONGATION

摘要

A film that is formed from a thermoplastic composition is provided. The thermoplastic composition contains a rigid renewable polyester and a polymeric toughening additive. The toughening additive can be dispersed as discrete physical domains within a continuous matrix of the renewable polyester. An increase in deformation force and elongational strain causes debonding to occur in the renewable polyester matrix at those areas located adjacent to the discrete domains. This can result in the formation of a plurality of voids adjacent to the discrete domains that can help to dissipate energy under load and increase tensile elongation. To even further increase the ability of the film to dissipate energy in this manner, the present inventors have discovered that an interphase modifier may be employed that reduces the degree of friction between the toughening additive and renewable polyester and thus reduces the stiffness (tensile modulus) of the film.