Study On Preparation And Properties Of Polyurethane Elastomer Composites With MDI Sistem

Polyurethane elastomer has excellent comprehensive properties because of its unique structural characteristics,and it can be used as rubber and plastic.Therefore,it is widely used in all aspects of modern society.However,there are many polar groups in polyurethane,which make the resistivity lower.Large number of hydrogen bonds in the molecule,and the internal friction of the molecules is larger,which leads to the larger internal heat generation under alternating stress.When the hollow microspheres were added into the polyurethane elastomer,the micro and closed pore structure which is different from that of the common polyurethane foam material can be formed.The polyurethane material with a fine closed pore structure,which is nearly elastic,can improve the dynamic performance of polyurethane without foaming agent.At the same time,the production process can be simplified.The addition of high dielectric constant inorganic filler can improve the resistivity of the materialThis topic mainly uses the one-step method to prepare the polyurethane elastomer composite material of MDI system,and carries on the research from the following aspects : properties of composite matrix,effect of hollow glass microspheres on properties of elastomers,effect of organic hollow microspheres on the properties of elastomers,Effects of inorganic fillers and modification on properties of composites.Through the experimental data we can find:(1)Changing the type and proportion of polyols can find: The synthesis properties of the material were better when using polyether three alcohol M-1 and polymer polyol J-1 as the ratio of 60/40.Changing the type and proportion of chain extender can find:When the ratio of EG and E-300 is 1/1,the comprehensive performance of the material is better.When changing NCO%,it is found that NCO% is 2%,which meets the performance requirements.Changing variety and proportion of isocyanate can find that the comprehensive performance of the material was better when using 100 L alone.(2)The variation of the hollow glass microspheres showed that the strength of the microspheres decreased less when the microspheres were S60.S60 and VS5500 improve the resilience of the material.VS5500 decreases the resistivity of the material in minimum degree,followed by S60.VS5500 and S60 have better effect on improving dynamic performance.On the whole,the comprehensive effect of S60 is better.Changing the amount of HGM can find that the more the amount of S60,the more strength and resistivity of the material decreased,but the impact rebound of material is higher,and the dynamic performance is improved greatly.On the whole,the comprehensive performance is better when the amount of S60 is 2%.(3)Changing the type of organic hollow microspheres can find: the performance of AK920 is better in physical performance,the resistivity decreased in minimum degree with adding non-foaming AK31-40.In the aspect of dynamic performance,the dynamic and static stiffness ratio and loss factor of the material are the smallest with using AK920.Changing the amount of organic microspheres find that the mechanical properties of the material and the resistivity decreased less when the dosage of AK920 is 0.25%,and the static and dynamic stiffness ratio reaches the minimum value.Combining the organic hollow microsphere and different HGM finds that coordination effect of AK920 and S60 is better,but the effect is not good enough to use AK920 alone.(4)Changing the inorganic filler can find that the mechanical properties and dynamic properties are better when the filler is Ba SO4.When the filler is titanium dioxide,the surface resistivity and volume resistivity of the material are higher.Changing the amount of inorganic filler find that the more the amount of BaSO4,the worse the mechanical properties of the material,but the higher the surface resistivity and volume resistivity,and the dynamic properties of the material are affected,but the influence is little.The dosage of BaSO4 can be added to 25 g.Changing the thixotropic agent can find: When the amount of thixotropic agent is 0.5%,the mechanical properties of the material are better,the hardness difference is smaller,but the viscosity is the larger.When the amount of thixotropic agent is 0.5%,the surface resistivity of the material has a small difference between both sides and the volume difference is large.Changing the surface modification of inorganic fillers can find: After the modification of BaSO4 with aluminate coupling agent,the mechanical properties,electrical resistivity,dynamic properties and dispersion of the material are better.When the dosage of aluminum acid ester is 6% and the modification time is 30 minutes,the comprehensive performance of the composite is better.