| Toughening is an important aspect in the field of polymer blends , the development of its theory mainly underwent a series of microcracks , mutiple crazing , shear yielding and crazing with shear yileding theory . At present , it is developing toward the quantity . In 1984 , Japanese Kurauchi and Ohta first put forward the theory of toughening , which is in contrast with former theories , that is the toughening mechanism by rigid disperse phase through cold-drawing . A polymer blend is composed of continuous matrix and diperse phase , so the dissipation of the impact energy must be fulfilled by the two parts together , which has not been recognized by all previous theories . Merz and Kurauchi believed that the dissipation of polymer blend's impact energy is accomplished by the deformation of disperse phase by either preventing the increment of crazing into elastic energy or forcing deformation into plastic energy , neglected the part absorbed by matrix . Bucknall , Newman and Yee ignore the contribution of the disperse phase absorbing impact energy , they believed , the disperse phase only plays the role of stress concentration , which changes the stress site of matrix in the polymer blend , it is those crazing and yield shear bend which are created by the matrix and which is induced by the stress concentration of disperse phase that dissipate the impact energy geniously . These toughening theory are one-sided and superfical in the recognization of polymer blend's toughening . They grasp only one aspect of the discrepancy , and ignore the other aspect of discrepancy which plays .General toughening theory of polymer blend believes: at present, people's recognitation to toughening phenomen is as that to light before the formation of the theory of wave-partial properties , which had not grasp the basic point that influence the development , that is not full-bodied .General toughening theory supposes : the disperse phase disperses...
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