Investigation Of Novel [N, Si, N, P] Metal Catalysts Containing Fluorine For Copolymerization Of Ethylene And Vinyl Amino Acid Ester

2,4,6-trifluoroaniline, aniline, chlorodiphenylphosphine and dichlorodimethylsilane were used as raw materials, under the action of Grignard reagents, to form novel complexes containing fluorine substituent through the elimination of hydrogen halide. After reacting with metal halides,[N, Si, N, P] transition metal complexes with five-numbered heterocyclic ring were generated, which had no carbon atom on the complex’s ring. The structure of ligands and complexes were characterized by1H NMR and EA. Vinyl bromides(4-bromo-l-butene,6-bromo-1-hexene,8-bromo-1-octene and10-bromo-l-decene) and N-acetyl-L-tyrosine ethyl ester were used to synthesize four kinds of terminal vinyl amino acid ester monomers with different length of carbon chain. The molecular structure of these monomers were identified by1H NMR, EA, MS and FT-IR.[N, Si, N, P] transition metal complexes played a role as catalytic precursor, under the activation of MAO, to catalyze the homoporymerization of ethylene and copolymerization of ethylene and vinyl amino acid ester, which showed good catalytic activity with2.04×106gPE (mol M)-1h-1and6.56×104gP (mol M)-1h-1respectively. By investigating the effects of the carbon chain length of vinyl amino acid ester, metal center, reaction temperature, mole ratio of Al to M, comonomer concentration and pretreatment method of polar monomer on copolymerization results, the optimal condition for copolymerization was obtained:L-Pd complex catalyzed ethylene copolymerizing with vinyl amino acid ester pretreated by AlEt3under activation of MAO at50℃, the catalytic activity of the complex and insertion rate of vinyl amino acid ester can reach the best level when the mole ratio of Al to M was600and comonomer concentration was10g/L.13C NMR, FT-IR, DSC, WAXD, fluorescence analysis and water contact angle were used to characterize the molecular structure and property of poly(ethylene/vinyl amino acid ester) comprehensively. The results of13C NMR showed that when using L-Pd as catalyst on the copolymerization of ethylene and hexenyl-N-acetyl-L-tyrosine ethyl ester, the comonomer insertion rate reached2.37mol%within the copolymer chain; DSC results indicated that the copolymer melting temperature reached138.6℃, which was higher than that of polyethylene with melting temperature of134.3℃.