Study On Novel High-Temperature Performance Polyurethane Based On Phthalazinone Moieties For Leather

At present,the traditional polyurethane materials used in leather field can not meet the performance requirements of special fields because of defect of their intrinsic properties,such as poor using temperature and low wear resistance,especially poor using temperature,which greatly limited the use of polyurethane leather products.In this article,some polyol polymers,such as PTMG 2000 or PCL 2000,was replaced by 4-(4-Hydroxylphenyl)(2H)-phthalazin-1-one(DHPZ)to synthesize a novel polyether type or polyester type high-temperature polyurethane based on phthalazinone moieties for Leather.A molecular reaction model experiment of 4,4-diphenylmethane diisocyanate(MDI)with DHPZ was designed to investigate the reactivity of isocyanate(-NCO)with active hydrogen in the structure of-NH in DHPZ.~1H-NMR showed that DHPZ could react with isocyanate(-NCO)in MDI at 110?.The polyurethane materials based on DHPZ monomer was characterized by FT-IR and XRD.The results showed that the polyurethane with phthalazinone moieties was successfully prepared,and the product had amorphous structure.When 1%DHPZ was added in the polymer,the initial thermal decomposition temperature Td1%of the polyether polyurethane material was 296°C,10%more than tradition PU.The elongation at break was994%,compared with traditional polyether-based polyurethane materials,the reduction is only 1.88%.The modulus of elasticity was 3.5 MPa,6.1%more than tradition PU and the tensile strength was 28 MPa,16.8%more than tradition PU.Polyester polyurethane has excellent overall performance when added with 1.2%DHPZ,which has the Td1%was 292°C,16.8%more than tradition PU.The elongation at break was 850%,the modulus of elasticity was 11.6 MPa,and the tensile strength was 52 MPa.The highly reactive phthalazinone-containing diamine,2-(4?-aminophenyl)-4-(4?-aminophenyl)-2,3-naphthyridin-1-one(DHPZ-DA),was used to replace the glycol chain extender 1,4-butanediol(1,4-BD)in some traditional polyurethane.Molecular reaction model compounds of MDI and DHPZ-DA were designed to investigate the reactivity of isocyanate(-NCO)with active hydrogen in the(-NH2)structure of DHPZ-DA,~1H-NMR proved that DHPZ-DA primary amine(-NH2)could react with(-NCO)in MDI.Polyurethane with DHPZ-DA as chain extender was sucessfully synthesized and then characterized by FT-IR.Its amorphous structure was confirmed by XRD.TGA and mechanical properties test showed that:with the increase of DHPZ-DA content,the Td1%of resuting polyurethane was increased from 227°C to 272°C.Its elongation at break was reduced from 778%to 408%,the modulus of elasticity was increased from 3 MPa to 45 MPa,and the tensile strength was 19 MPa to 47MPa.The leather products were fabricated by the polyurethane based on DHPZ monomer and the polyurethane based on DHPZ-DA diamine chain extender to test for TABER wear resistance,normal temperature folding resistance,low temperature folding resistance,hydrolysis resistance in various conditions,and mechanical property testing.The comprehensive results showed that with the increased of DHPZ or DHPZ-DA ratio,the wear resistance of polyether polyurethane and polyester polyurethane based on DHPZ monomer increased 57.1%and 66.3%respectively,the folding resistance,the hydrolysis resistance and mechanics of the leather were excellent.