The Fracture Behavior Investigation Of High Density Polyethylene Modified Materials

This Paper investigated the fracture behavior of HDPE/wollastonite/POE-g-MAH and HDPE/PC/POE-g-MAH composites under low strain rates. Thetheoretical foundation of this work is the EWF method. The effect of the wollastoniteand PC content on the fracture Parameters was discussed; Reasonable and effectivemethod was used to segmentation the energy dissipation in the tensile fractureprocess of the DENT samples; It also studied the relationship between the Fracturetoughness and impact toughness; The morphology and fracture topology ofHDPE/PC/POE-g-MAH blends were observed by scanning electron microscopy(SEM), Changes of PC content in the fracture parameters as a function wereinvestigated in terms of the microstructure of the materials.The fracture behavior of HDPE/wollastonite/POE-g-MAH composites showedthat with increasing wollastonite content the essential work of fracture (we) increased,while the non-essential work of fracture (βwp) decreased. The fracture toughness ofthe composites was mainly affected by the crack propagation resistance during thenecking and tearing processes after yielding; the plastic deformation capability of thematerial depended mainly on the properties of fracture behavior after yielding too. Itwas also found that the impact strength of the material decreased with increasingwollastonite content. The materials with high impact strength, however, had lowspecific essential work of fracture.For HDPE/PC/POE-g-MAH blend, the strength increased and the impactstrength decreased with increasing PC content, the MFR did not change significantly;The wevalues of HDPE/PC/POE-g-MAH blend significantly increased withincreasing PC content, but the values of βw_pdecreased, the evolution of weand βw_pwas mainly achieved through the variation of we,nand β″wp,nrespectively. Effect ofspecimen thickness on fracture behavior of HDPE/PC/POE-g-MAH wasinvestigated, it was found that the specific essential work of fracture(we) decreasedwith increasing the thickness of specimens, but the specific nonessential work offracture(βwp) did not change.SEM micrographs indicate that the morphology of HDPE/PC/POE-g-MAHblends is that small spherical particles of PC disperse in matrix. The fracture surfacesare quite rough, an indication of ductile fracture. Some of the PC particles deformed and broke during the fracture process, while others were pulled out, leaving voids inthe matrix, PC particles play the role of passing stress and stable crack. PC particlesdeformation, orientation hinder the unstable growth of the precrack under low strainrates.