STUDY OF FRACTURE MECHANISMS OF MULTIPHASE POLYMERS USING THE DOUBLE-NOTCH 4-POINT-BENDING METHOD

The double-notch four-point-bend technique (DN-4PB) is developed to st udy the fracture mechanisms of multiphase polymers. This technique is found to be effective for an unambiguous determination of the fracture mechanisms and the sequence of toughening events of polymer alloys wh en fracture occurs. The DN-4PB technique is also found to be especiall y useful for situations where the quantity of the test material is lim ited and the testing rate is high. The present study demonstrates the usefulness of the DN-4PB technique in a variety of polymeric systems a nd testing conditions. Requirements for which the DN-4PB technique bec omes useful are also addressed.