Study On The HDPE And Nano-CaCO₃ Composite Impact Toughness

This thesis inspect changes of impact strength that HDPE at different temperature, different notch depth and different impact rate, analyzed the impact - displacement curve using the material's toughness parameters DI, analyzed quantitatively the HDPE toughness changes from the perspective of energy. In order to provide data for improving the toughness of HDPE. These experiments show that: the HDPE's impact strength obviously decreases when the experimental temperature drops,notch depth increases and the impact rate improves.At the same time under different temperature conditions impact cross section SEM observation,revealed with decreasing temperature, the flatter middle section with alternating white and rough parabola with morphology, micro-fiber pattern on both sides of the silver mirror surface area consisting of trend to reduce, mirror zone was ductile fracture.In the experiment got the nano-CaCO3/HDPE composite through the method of the double-roll blending machine for blending and the flat vulcanizing machine for molding; studied the nano-CaCO3 content how to affect the nano-CaCO3/HDPE composite'impact and tensile properties; Analyzed the nano-CaCO3/HDPE composite's impact fracture using SEM and found that: When the nano-CaCO3 content was 1% to 3% range, nanoparticles are distributed in the HDPE matrix is more uniform particle size smaller reunion, when the nano-CaCO3 content of 5% to 6%, the reunion of the particle size can be as large as 5μm.Dispersant EVA3 added to the composite nano-CaCO3/HDPE significantly improved its mechanical properties, EVA3 composite nano-CaCO3/HDPE best dosage of 0.2%. This paper also examines EVA3 amount of 0.2%, the content of nano-CaCO3 composite materials on the nano-CaCO3/HDPE impact properties and tensile properties, show that: EVA3 was added nano-CaCO3/HDPE composite impact strength, yield strength, elongation at break and so on with varying degrees of increase. SEM surface observation revealed: after adding dispersant EVA3, nano-CaCO3 particles in the HDPE matrix, the distribution has greatly improved, especially the particle size significantly decreased.