Effect Of Modified Graphene Oxide On Properties Of Thermoplastic Polyurethane

The graphene oxide(GO)was modified by 1,6-hexaprodiisocyanate(HDI),4,4 ’-diphenylmethane diisocyanate(MDI),isophorone diisocyanate(IPDI)and toluene diisocyanate(TDI).The modification effects of different isocyanates were analyzed by means of FTIR,XRD,Raman and XPS.The results show that IPDI has the best modification effect,increasing the defect density and layer spacing of GO from 0.71 nm to 1.28 nm.The modified GO/TPU nanocomposites were prepared by prepolymer method using MDI,polytetrahydrofuran ether diol(PTMG1000)and 1,4-butanediol(BDO)with molecular weight of 1000 as raw materials.The effects of GO modification on the properties of TPU composites were investigated by FTIR,TG,DSC,DMTS and mechanical properties.The results show that the modified GO/TPU nanocomposites have higher degree of hydrogen bonding,lower Tg,stronger hydrophobicity and mechanical properties.But the energy storage modulus and thermal decomposition temperature decrease and the loss factor increases.Among them,the hydrogen bonding degree of GO modified by IPDI is the highest,Tg is the lowest,which is-65.6℃,tensile strength is 35.9 MPa,elongation at break is 570%.Compared with the unmodified GO/TPU composites,the tensile strength and elongation at break were increased by498% and 93%.This paper also explores the optimal filling amount of IPdi-modified GO by changing the mass fraction of IPdi-modified GO.The properties of the composites were characterized by FTIR,SEM,TG,DSC,DMTS and mechanical properties.The results show that the dispersion of GO in TPU decreases when the filling amount of IPDI modified GO exceeds 0.2wt %,and the composite with 0.2wt % filling amount has the best dispersion.With the increase of the filling amount of modified GO,the degree of hydrogen bonding and mechanical properties first increased and then decreased,while Tg first decreased and then increased.The change of filling amount has little effect on hydrophobicity,initial thermal decomposition temperature and HS decomposition temperature.The hydrogen bonding degree of the composite with 0.2wt % filling is the highest.The lowest Tg was-65.6 ℃,the tensile strength was 40.8 MPa,and the elongation at break was 708%.Compared with GO/TPU composites,tensile strength increased by 508% and elongation at break increased by 139%.