Study On Synthesis Of Aromatic Polyamides By Heterogeneous Palladium-Catalyzed Carbonylative Polycondensation And Heck Coupling Polycondensation

In this dissertation,we have investigated heterogeneous palladium-catalyzed carbonylation polycondensation and Heck coupling polycondensation by using magnetic nanoparticles-supported bidentate phosphine palladium complexes as catalysts to synthesize various new aromatic polyamides.The research works are mainly divided into three parts as follows:1.Two new aromatic diiodides with ether sulfone linkages were prepared in a one-step synthesis.A series of poly(arylene ether sulfone amide)s were synthesized by heterogeneous palladium-catalyzed polycondensation of aromatic diiodides with ether sulfone linkages,aromatic diamines,and carbon monoxide.Polymerizations were conducted in N,N-dimethylacetamide(DMAc)at 120 ? in the presence of a magnetic nanoparticles-immobilized palladium(?)complex[Fe3O4@SiO2-2P-PdCl2]and 1,8-diazabicycle[5,4,0]-7-undecene(DBU),yielding a series of poly(arylene ether sulfone amide)s with inherent viscosities up to 0.77 dL/g.The polymers obtained were quite soluble in dipolar aprotic solvents and showed glass transition temperatures in the 204-265 ? range and 10%weight loss temperatures of 456-492 ? in nitrogen.Most of the polymers afforded transparent and tough films by solution-casting with tensile strengths of 71.8-82.2 MPa,tensile moduli of 1.77-2.35 GPa,and elongations at break of 9.3-13.4%.More importantly,this heterogeneous palladium catalyst can be facilely separated from the reaction product by simply applying an external magnet and reused at least seven times with almost consistent activity.2.A series of poly(imide-amide)s were synthesized by heterogeneous palladium-catalyzed polycondensation of aromatic diiodides with imide groups,diamine compounds with cardo structures,and carbon monoxide.Polymerizations were conducted in DMAc at 100 ? in the presence of a magnetic nanoparticle-immo-bilized palladium(II)complex[Fe3O4@SiO2-2P-PdCl2]and DBU,yielding a series of poly(imide-amide)s with inherent viscosities up to 0.65 dL/g.The polymers obtained were soluble in dipolar aprotic solvents and showed glass transition temperatures in the 237-268 ? range in nitrogen.The polymers films by solution-casting had tensile strengths of 71.5-88.3 MPa,tensile moduli of 1.51-1.81 GPa,and elongations at break of 8.5-13.2%.This heterogeneous palladium catalyst can be recycled at least eight times with almost consistent activity.3.Two diene compounds containing amide groups were prepared.A series of polycinnamamides were synthesized by heterogeneous palladium-catalyzed Heck coupling polycondensation of diene monomers and aromatic diiodides.Polymeriza-tions were conducted in DMF at 100 ? in the presence of a magnetic nanoparticles-immobilized palladium(?)complex[Fe3O4@SiO2-2P-Pd(OAc)2]and tributylamine,yielding a series of polycinnamamides with inherent viscosities up to 0.84 dL/g.The polymers obtained were quite soluble in dipolar aprotic solvents and showed glass transition temperatures in the 222-269 ? range and 10%weight loss temperatures of 437-458 ? in nitrogen.Polymers afforded transparent and tough films by solution-casting with tensile strengths of 53.6-82.8 MPa,tensile moduli of 1.78-2.01 GPa,and elongations at break of 7.5-11.1%.This heterogeneous palladium catalyst can be recycled at least eight times without significant loss of activity.