Research On Preparation And Mechanical Properties Of Carbon Fiber Reinforced High-density Polyethylene

Carbon fibers are inorganic fibers consisting of at least90%carbon.Carbon fibers combine low weight and exceptional mechanical properties, making them ideal reinforcements for composite materials, such as fiber reinforced plastic、metal、 ceram、cement and carbon-carbon composite. In this paper, the thermoplastic high density polyethylene resin was used as research object and was firstly blended with carbon fiber to get the HDPE/CF binary composites. The influence of the different amount of CF on the properties of HDPE was researched.The PE-g-MAH was used as compatibilizer to improve the interfacial properties of HDPE/CF.Then the HDPE/CF binary composites was modified by three different toughening agents (HGB, CaCO3, POE), and the effects of this three different toughening agent were compared.It was found that the modification effect of CaCO3was better than HGB and POE. The CF, PE-g-MAH, CaCO3were used as three influential factors of the mechanical properties of the composites to design the orthogonal test. The composites’properties were tested.Finally we got an enhanced HDPE/CF/CaCO3/PE-g-MAH quaternary system.Firstly,the thermoplastic high density polyethylene resin was blended with carbon fiber to get the HDPE/CF binary composites. With the increased of carbon fibers’content in this composites, the tensile strength and bending strength increased, but the impact strength decreased gradually.The fluidity of thermoplastics decreased and the Vicat Softening Poin increased, the interface between CF and HDPE was poor.Secondly, the PE-g-MAH was used as compatibilizer to improve the interfacial properties of HDPE/CF.It was found that with the increase of PE-g-MAH’s content in the composites, the tensile strength and bending strength decreased, but the impact strength increased gradually. The interface between CF and HDPE was improved.Thirdly, the HDPE/CF binary composites was modified by three different toughening agents (HGB, CaCO3, POE), and the effects of this three different toughening agent were compared.It was found that modified effect of CaCO3was better than HGB and POE.Finally, the CF, PE-g-MAH, CaCO3were used as three influence factors of the mechanical properties of the composites to design the orthogonal test. The influence of this three influence factors on HDPE’s mechanical properties, thermal properties and rheological properties were researched. Through experiments the appropriate formula was determined. The appropriate formula was HDPE/CF/CaCO3/PE-g-MAH(100/15/10/6). After analysed properties of this composite,it was found that the impact strength increased larger. The notched impact strength of this composite was10.39kJ/m2, it was38.5%higher than HDPE(7.5kJ/m2).Both the tensile strength(42.17MPa) and bending strength(60.12MPa) were increased, respectively66.29%and137.52%higher than HDPE. The Vicat Softening Poin was80.6℃which was41.33%higher than HDPE(70.5℃). The melt flow rate was5.67g/10min,it was decreased slightly than HDPE(6.31g/10min).The fracture structure gained by SEM showed that these components dispersed evenly in the composite and the interface was improved.