Study On Modification And Application Of Polyethylene Plastics

Polyethylene is the most widely used polymer material and the largest consumption of synthetic resin in the world.In this paper,the research progress of the modification of different polyethylenes were summarized,and then the modification and application of two polyethylene resins,LLDPE and HDPE were studiedIn this paper,high-speed mixing,granulating through twin screw extruder,and film-blowing through single screw extruder were used to prepare different modified polyethylene films.First,inorganic nucleating agent A,sorbitol organic nucleating agents B and C,and compound nucleating agent were used to modify two LLDPE resins with different melt flow rates,respectively.The influence of LLDPE resin melt flow rate and film optical properties,mechanical properties and crystallization properties were analyzed,respectively.XRD and SEM were used to characterize the crystallinity of film and the morphology of film and nucleating agent.Then for the PPA lubricant on LLDPE 7042 film,the effects of dynamic friction coefficient,mechanical properties,different light stabilizers and compound stabilizers on the mechanical properties of LLDPE 7042 film 24h UV aging were studied.Finally,the mechanical properties of the composite materials prepared by the process of glass fiber or glass fiber treated with different coupling agents and HDPE by twin screw blending,extrusion granulation and injection molding were studiedThe modification study of LLDPE 1875 by nucleating agent shows that with the increase of the content of inorganic nucleating agent A,the crystal grains of the resin gradually decrease,and the crystallinity of the film gradually increases.As the melt flow rate of the resin is the highest of 2.7g/10min,it is 150%higher than the blank sample The film haze is the lowest of 13.5%,which is 38.8%lower than the blank sample.The light transmittance is 93.7%and increased by 1.8%compared with the blank sample.The tensile strength reached 30.6MPa,which was increased by 9.3%compared with the blank sample.The modification result of LLDPE 7042 by nucleating agent shows that with the addition amount of inorganic nucleating agent A 1000 ppm,the melt flow rate of the resin reaches the highest of 5.7g/10min,which is 53.9%higher than the blank sample.The film haze reaches the minimum value is 13%,which is 23.5%lower than the blank sample,and the light transmittance is increased by 2.4%,The tensile strength reaches 28 MPa,which is 19.1%higher than the blank sample.SEM shows that the more uniform size of the inorganic nucleating agent A in the resin,the better performance of film isThe modification result of LLDPE 7042 film by PPA lubricant shows that as the content of PPA increases,the dynamic friction coefficient of the film gradually decreases The amount of PPA-2 added by 3M is 300ppm,and the dynamic friction coefficient of the film is the smallest,reaching of 0.19,which is lower than the blank sample of 30.4%Tensile strength increased to 21.8MPa,which was 14.3%higher than the blank sampleThe results of different light stabilizers and compound modified LLDPE 7042 film show that as 150 ppm hindered amine light stabilizer 770 and 300 ppm UV absorber UV-531 are used together,the film has the highest mechanical properties after 48h accelerated aging and the aging rate slowestThe research on the modification and enhancement of HDPE resin by glass fiber shows that with the increase of the amount of glass fiber,the tensile strength of HDPE composite material gradually increases.When the amount of glass fiber is 50%,add 3mm long glass fiber HDPE composite,the tensile strength of the material reaches the highest value of 71MPa,which is 117.6%higher than that of the blank sample,When the amount of surface modifier KH-550 is 1%of the mass of glass fiber,the tensile strength of the composite material is less than that of the surface modifier.The sample increased by 14.4%and the impact strength increased by 2.2%.