Study On Structure And Properties Of HDPE/TPI/Nanoparticles Ternary Composite

High density polyethylene（HDPE）as a universal plastic is widely used,and has many advantages,including high application temperature,good barrier property to gas,and anti-corrosion to chemicals and so on.Beside HDPE is easily to process,non-toxic and has wide range of application.Compared with engineering plastics,HDPE has some disadvantages,such as poor toughness,low hardness and bad environment stress cracking property,which limited its application as structural materials.Therefore,modification of HDPE has become a hot topic for researchers.This work stuied the HDPE/TPI/nanoparticles ternay composites was prepared by HDPE、trans-polyisoprene（TPI）and nanoparticles adopting the melt blend method,and further explored the modification of thoughening and reforcing by TPI and nanoparticles.Part one,HDPE/Nano-CaCO₃ composite and HDPE/OMMT composite were prepared by two screw extruder.The effect of nanoparticles content on the mechanical properties,heat resistance and microstructure of blends were studied.The results indicated that,the notched impact strength,tensile strength,rigidity and heat resistance of HDPE were improved with a certain content of nanoparticles（the content of Nano-CaCO₃ was 3%,OMMT was 4%）.It was shown by scanning election micrograph,nanoparticles were uniformity dispersed in the matrix and no obvious agglomeration with the small content of nanoparticles.Part two,the effect of TPI content on the performance of HDPE was studied by four different processing methods,in which TPI was vulcanized using sulfer vulcanization system.The results showed that,there were two processing methods,HDPE and TPI blended by extruder and then reaction extrusion with the sulfur vulcanization system by twin-screw extruder;the TPI and sulfur vulcanization system mixed with the mixer and then HDPE and masterbatch reaction extrusion by two screw extruder.The HDPE/TPI blends had good perpormances by using two processing methods above.The optimum ratio was HDPE/TPI=85/15.Part three,under the ratio of HDPE/TPI=85/15,the effect of crosslinking density on the performance of HDPE/TPI blends was studied with the change of sulfur content by using two processing methods mentioned above.It turned out that,the HDPE/TPI blends had the best performance when the content of sulfur were 2phr.Part four,under the ratio of blends was HDPE/TPI=85/15 and the sulfur content was 2phr,the properties of HDPE/TPI blends were studied with different nanoparticles contents by different processing methods.The results showed that,when the content of Nano-CaCO₃ was 3%,OMMT was 4%,the HDPE/TPI/nanoparticles ternary composite materials had the better comprehensive performance by melt blending HDPE and TPI and then reaction extrusion with the sulfur vulcanization system and the nanoparticles.When the content of Nano-CaCO₃ was 3%,HDPE/TPI/Nano-CaCO₃ ternary composite materials had the best comprehensive performance by mixing TPI,sulfur vulcanization system and Nano-CaCO₃ with the mixer and then reactive melt-blending with the HDPE.