Study On Preparation And Mechanical Properties Of OMMT-Al₂O₃/PUE Composite

Polyurethane elastomer?PUE?is a thermoplastic material with excellent comprehensive properties.It can be used in many fields,such as aerospace,marine,railway,industrial,civil and so on.The applications of PUE are limited in many areas because of its high internal friction and heat resistance,solvent resistance,mechanical properties and damping performance are poor.The performance of PUE is not only affected by its own structure,but also related to the fillers.The inorganic particles can improve the comprehensive performance of the PUE.So in-depth study of the relationship between PUE properties and the kinds and amounts of fillers has great significance to the development and use of materials.In this paper,sodium montmorillonite?MMT?was modified by octadecyl trimethyl ammonium chloride?OTAC?via cation exchange to obtain organo-montmorillonite?OMMT?,alumina??-Al2O3?was modified by KH-550 via hydrolysis method to get KH550-Al₂O₃.PUE was synthesized,in which polypropylene glycol?PPG?and 4,4'-diphenylmethane diisocyanate?MDI?as raw materials,1,4-butylene glycol?BDO?as chain extender.OMMT/PUE,KH550-Al2O3/PUE and OMMT-Al2O3/PUE nanocomposites were prepared by pre-polymer method and OMMT and KH550-Al2O3 as modifier.The micro-structures of inorganic particles and composites,the dispersion of inorganic particles in PUE matrix and the variation of the montmorillonite layer spacing were observed by FT-IR,SEM,TEM,XRD and muffle furnace.The tensile strength,elongation at break,tensile strength at break,storage modulus,glass transition temperature and damping factor of composites were tested by static mechanical test and dynamic mechanical test.The results showed that the single component of OMMT or KH550-Al₂O₃ had the best dispersion in the PUE matrix when the additive amount was 3 wt%,and the mechanical properties of OMMT/PUE composites were better than that of KH550-Al₂O₃/PUE composites.The tensile strength,elongation at break and tensile strength at break of OMMT-Al₂O₃/PUE composites were better than those of the composites modified by the individual components,were 21.82 MPa,668%and 19.98 MPa,respectively,which were 34%,25%and 32%higher than those of PUE matrix,and were significantly improved by 4.9%,2.5%and 1.7%than those of OMMT/PUE composites,severally,when the mass ratio of OMMT and KH550-Al₂O₃ was 1:1and the amount was 3 wt%.In brief,static mechanical properties of composites had obviously improved.When the addition amount of inorganic particles was 3wt%in the PUE matrix,the storage modulus and loss factor of OMMT-Al₂O₃/PUE composites were the biggest and were 2.69×109 Pa and 1.191,respectively,which were 10.25%and 3.75%higher than those of OMMT/PUE composites.In a word,comprehensive mechanical properties of composites were excellent.