Preparation And Properties Of Nano-CaCO₃/OMMT/HDPE Ternary Composite Plastics

High Density Polyethylene (HDPE) has been used in the filed of pipe production and packing industry because of its stable chemical property. The application of HDPE is limited due to its low intension, labile shape, thermolabile and inflammable properties. The performance can be increased by using physical methods of adding nano-inorganic particle into HDPE.Nano CaCO₃ and OMMT (organic montmorillonite) are two common nano-inorganic particles. The impact strength and Young's modulus of binary composite plastic are increased with the adding of nano-CaCO₃. The tensile strength and thermo stability of binary composite plastic are enhanced with the adding of OMMT. In previous work simple inorganic particle is used and results the improvement of some properties and the decrease of other properties at the same time.In this paper, at first the composite plastic have been made from HDPE, PE-g-MAH and nano-CaCO₃ which altered by stearic acid. Their tensile properties have been studied. The disperse of inorganic ions into HDPE can be improved by using nano-CaCO₃ altered with 7% (wt) stearic acid and so that the tensile properties of composite plastic are increased. The molecular length of stearic acid has been extended by bounding with PE-g-MAH. The intensity of tension has been enhanced depending on the intertwist between enlarged stearic acid and HDPE matrix. After that, ternary composites plastic has been prepared by adding two different kinds of nano-inorganic particles, Nano-CaCO₃ and OMMT, into HDPE at the same time. Its mechanical properties, thermodynamic properties and micro structures are investigated. The results showed that the tensile strength, Young's modulus, flexural strength, elastic modulus and impact strength of nano-CaCO₃/OMMT/HDPE can be increased 124.6%, 302.7%, 73.86%, 58.97% , 27.25% respectively. Its decomposing temperature is increased 30℃. The crystalline degree and speed of ternary composite plastic are increased. All of these improvements are caused by the synergistic effect of two different nano-inorganic particles.