Preparation And Properties Of Marine Silicone Modified Polyurethane Damping Material

In this study,diphenylmethane diisocyanate(MDI),polyoxypropylene diol(PPG)was used as the reactive monomer,1,4 butanediol(BDO)was used as the chain extender,and the chain extension coefficient was 1.05.The polymer preparation method was used to synthesize hard segment polyether polyurethane damping materials with different contents,and used Fourier transform infrared spectroscopy(FT-IR),dynamic mechanical analysis(DMA),thermal weight loss(TGA),differential scanning calorimetry(DSC),scanning electron microscopy(SEM)and other techniques to characterize the properties of the material,and the tensile strength,elongation at break,and Shore hardness of the material were also tested.The experimental results show that the damping property of the material decreases with the increase of the hard segment ratio.The heat resistance of the material is the best when the hard segment is the least,and the glass transition temperature of the hard segment is gradually reduced.When the content is gradually increased,the tensile strength and Shore hardness of the material gradually increase,and the elongation at break gradually decreases.Considering the comprehensive properties of the material,it is determined that the polyurethane damping material with a hard segment content of 45 % is modified by silicone.The polyurethane block was modified by hydroxyl terminated silicone oil,and the effect of the amount of hydroxyl terminated silicone oil on the properties of the composite damping material was studied.The content of hydroxy silicone oil was determined by the best damping performance.The composites were characterized by FT-IR,DMA,TGA,DSC and SEM.Infrared spectroscopy results show that the silicone successfully polymerized block-modified polyurethane,and the silicone-polyurethane composite material was obtained.With the increase of the amount of hydroxy silicone oil,the damping property of the composite material increased gradually,and the damping temperature range was expanded while the damping performance was the best.The temperature is shifted to the low temperature direction,the heat resistance of the material is gradually enhanced;the tensile strength of the material is gradually increased,the Shore hardness is gradually decreased,andthe elongation at break is first increased and then decreased,and the content of the terminal hydroxyl silicone oil is 8 %,the elongation at break reached a maximum of432 %.A composite damping material with a hydroxyl silicone oil content of 8 % was selected for the modification of the filler.The effect of filler on properties was studied by adding different content of mica powder and talcum powder into the composite damping material.The results show that sericite and talcum powder can improve the damping properties of the material.The maximum loss factor of the 10 % talcum powder modified composite at 65 ? is0.442,and the 10 % sericite modified composite at 65 ?.The maximum loss factor is0.436;both inorganic fillers can enhance the heat resistance of the material,and the tensile strength and Shore hardness of the sericite-modified composite increase with the addition amount,and the elongation at break first rises.Furthermore,when the addition amount is 8 %,the maximum value is 473 %,and the tensile strength,elongation at break and Shore hardness of the talcum powder-modified composite increase with the addition amount.