Strength Development at the Interface of Amorphous Polymers and Their Miscible Blends, below the Glass Transition Temperature

Bonding amorphous polystyrene (PS) and poly(2,6-dimethyl 1,4-phenylene oxide) (PPO) has been carried out in a broad range of temperatures and contact times (t), but always below the glass transition temperature (T g), in a lap−shear joint geometry. Strength at the symmetric and asymmetric polymer/polymer interfaces develops with t 1/4 and, hence, is diffusion controlled. The development of strength at the homopolymer/miscible blend interface below T g can be simulated from data for homopolymer/homopolymer interfaces, taking into account the wetting (and “fast diffusion”) and diffusion contributions to the development of strength.