Enhanced interfacial adhesion for effectively stress transfer inducing the plastic deformation of matrix towards high-toughness PC/PBT/EMA-GMA blends

The interfacial adhesion between polycarbonate (PC) and polybutylene terephthalate (PBT) is improved by insitu grafting reaction during melt blending, and the high toughness polycarbonate/polybutylene terephthalate/ethylene-methyl acrylate-glycidyl methacrylate (PC/PBT/EMA-GMA) blend is prepared. The results indicate that the matrix changes from brittleness to toughness gradually, and the impact toughness of the blends are greatly improved with the addition of EMA-GMA. When 4 wt % EMA-GMA is added, the toughness of the samples reaches the optimal value with the notched Izod impact strength and elongation at break reaching 79.3 kJ/m2 and 226.0%, which are 13.7 and 3.5 times of PC/PBT blends, respectively. The phase morphology, the effect of in-situ reactions on the relaxation behaviors of chains, and the mechanical properties of samples are systematically investigated. In the process of in-situ reactive blending, the EMA-GMA that is distributed between PC and PBT promoted the formation of interface layer, and the size of dispersed phase PBT decreased relatively. Meanwhile, the structure of PBT core coated by EMA-GMA soft shell is formed, which is conducive to producing the matrix ligaments and transmitting the stress. The toughening mechanism is mainly related to the reduced dispersed phase size, efficient stress transfer, and massive plastic deformation induced by the matrix ligaments throughout the matrix. This work provides a feasible method for the preparation of high toughness PC/PBT blend, and also it is of great significance to guide the preparation of other high toughness polymer blends.

Automated summary

The interfacial adhesion between polycarbonate and polybutylene terephthalate is improved by in-situ grafting reaction, leading to the preparation of high toughness blend. The phase morphology, relaxation behaviors of chains, and mechanical properties of the blend are systematically investigated.