HDPE/UHMWPE Co-blending Modification Research

HDPE has excellent chemical resistance,heat resistance,good thermal fluidity and low cost,but it has gradually failed to meet the needs of industrial production.UHMWPE has excellent mechanical properties,self-lubrication,low-temperature ductility and other properties,but the cost is high,the melt viscosity is large,and it is difficult to be molded by traditional extrusion processing.The molecular composition and structure of UHMWPE and HDPE are similar,and the compatibility is also better than other polymers.Therefore,in this paper,UHMWPE is used to modify HDPE,and HDPE/UHMWPE blends are prepared,and characterized by mechanical properties and thermal property analysis.In the paper,the effect of UHMWPE content on the properties of the blended material was mainly studied,and the feasibility of engineering general-purpose plastics was explored.After determining the optimum ratio,the HDPE/UHMWPE blends were modified with polyester resin,nylon 1010 and polyamide wax,respectively,and the effects of polyester resin,nylon 1010 and polyamide wax content on the properties of the ternary blends were investigated.Firstly,the HDPE/UHMWPE blends were prepared by the "two-step" method.The thermodynamic curves of the blended materials showed a single peak,which showed that the blended materials had phase homogeneity.With the increase of UHMWPE content,the crystallinity of the blended system showed an increasing trend.The results of the mechanical property test showed that the tensile strength of the HDPE/UHMWPE blended material gradually increased when the content of UHMWPE was less than 30%,indicating that the addition of the untwisting agent had a certain untwisting effect on the UHMWPE molecular chain and UHMWPE could play a strengthening role on HDPE.Secondly,after determining the optimal ratio of UHMWPE:HDPE,polyester was chosen to modify the HDPE/UHMWPE blends.The DSC test results showed that the ternary blends were compatible,and the addition of polyester increased the intermolecular chain distance,shifted the crystallization temperature of the blends to the high temperature region,and reduced the crystallinity of the blends.Shore hardness test results show that with the increase of polyester content,the Shore hardness of the ternary blend system decreases slightly.Mechanical properties test results show that when the polyester content is 0.8%,the tensile strength of the ternary blend system reaches 51.93 MPa,which is slightly higher than that of the binary blend system,indicating that the polyester is well bonded with the HDPE/UHMWPE blend material.The introduction of polar functional groups gradually increased the water absorption of the blended system.The melt index test results show that the addition of polyester has improved the fluidity of the ternary blend system.Then,PA 1010 was chosen to modify the HDPE/UHMWPE blend component.the DSC test results showed that the addition of PA 1010 affected the crystallinity of the ternary blend system.With the increase of PA 1010 content,the hydrogen bonding content in the blended material increased,and the mechanical property test showed that the tensile property increased with the increase of PA 1010 content,and the tensile strength of H/UH/A blended material reached the maximum value of 57.18 MPa when PA 1010 was added at 1.6%,and the Shore hardness test results showed that the hardness of the blended material gradually increased with the increase of PA 1010 content.The Shore hardness test results show that the hardness of the blended material gradually increases as the content of PA 1010 increases.The amine is easy to combine with water molecules,so the water absorption of the blended material also gradually increases.The melt index test showed that the fluidity of the ternary blends did not change significantly.Finally,when the UHMWPE blend was modified with PA wax,the DSC test showed that there were two melting peaks in the ternary blend,indicating that the PA wax was not well compatible with the HDPE/UHMWPE blend.The results of the mechanical properties test and Shore hardness test showed that the tensile strength and Shore hardness of the ternary blends decreased with the increase of PA wax content.The melt index test results showed that the polyamide wax acted as a lubricant and the polymer fluidity of the ternary blend increased with the increase of the polyamide wax content.The water absorption of the blended system increased with the increase of polyamide wax content due to the presence of amino groups.