MECHANICAL-BEHAVIOR AT FINITE STRAIN OF COALESCED CORE SHELL LATEX FILMS/

Uniaxial deformation at finite strain of coalesced core/shell (hard co re/film-forming shell) latex films is investigated by means of microme chanical calculations. Elongation ratios, strain rate, and energy dens ity distribution within the film are presented and confirm the strain amplification phenomenon well-known in the filled elastomer area. The important role of the core-shell interphase on the overall film mechan ical behavior is stressed by the presented results. Moreover, strain-s tress curves have been calculated without adjustable parameters and co mpared to experimental ones in order to gain substantial information a bout the deformation mechanism. It is then proposed that uniaxial defo rmation of coalesced core/shell latex films proceed through two simult aneous and/or successive mechanisms: isotropic matrix deformation and geometrical core rearrangement within the film. The stiffening of coal esced core/shell latex films appears therefore to be mainly due to mec hanical effects.