Characterization of High-Order Structure and Impact Strength of Multi-Phase Polymer Alloys

A quantitative characterization of the degree of agglomeration of the particles in multi-phase polymer alloy systems has been carried out. A numerical agglomeration distribution function and its 4 moments were calculated from SEM photographs using computer image analysis. In a model alloy system of PC/MBS a good correlation between the degree of agglomeration of the MBS and of the impact strength has been obtained. In PBT/PC alloys, the effect of mixing conditions in the heating rolls on the distribution of particle diameter, ligament thickness between particles and degree of agglomeration have been examined. A similar analysis has been carried out on on the PBT/PC alloys mixed with an extruder. The results showed that increasing agglomeration of the dispersed phase (PC) reduced the impact strength when the matrix was composed of high molecular weight PBT.