The effects of melt blending conditions on the rheology, crystallization kinetics, and tensile properties of phosphate glass/polyamide 12 hybrid systems were investigated for the first time, to understand their complex processing/structure/property relationships. Increasing amounts of phosphate glass (Pglass) caused an increase in hybrid viscosity. Hybrid viscosity was also affected by processing (melt-mixing) speed and small-amplitude oscillatory shear tests and scanning electron microscopy (SEM) were used for a qualitative examination of the hybrid morphology. The addition of Pglass caused a decrease in hybrid crystallinity that was unaffected by processing (melt-mixing) speed. The two-parameter Avrami equation was applied successfully to the hybrid systems, and Pglass was found to nucleate the growth of polyamide 12 crystals. The nucleation effect was found to be dependent on concentration and processing history. The tensile properties of the hybrids were also studied, and the Halpin-Tsai equation was applied to the results to determine the maximum packing fraction of the Pglass. These results provide a basis for the prediction of hybrid mechanical properties for different Pglass concentrations and processing histories. Further, because of their facile processibility and desirable characteristics, such as the strong physicochemical interaction between the hybrid components and favorable viscoelasticity, these Pglass/polyamide 12 hybrids can be used as model systems for exploring feasibility of new routes for driving organic polymers and inorganic Pglass to self-assemble into useful organic/inorganic hybrid materials. (c) 2007 Wiley Periodicals, lnc.