Toughening Phase separation role

The inclusion of rubber in polymers does, nevertheless, reduce the elastic modulus and the yield stress [53]. The phase separation between the polymer and the rubber is an important requirement, and mechanical resistance increases if the rubber has low elastic modulus in relation to the matrix, good adhesion to the matrix, adequate crosslinking, optimized average particle size and distribution, and low glass transition temperature [54]. The separating distance between the elastomeric zones also plays an important role in the toughening mechanisms. 

The addition of the rubber component resulted in a decrease in the modulus and yield stress. However, toughening and an improvement in the impact behavior were observed. The phase separation and formation of the rubbery domains played an important role. 

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