The catalytic effectsof Ln3+ on synthesis of polyethyleneterephthalate and its copolyesterswere studied. The direct esterification reaction of terephthalate acidwith ethylene glycol can be accelerated hy addition of Ln3+, and theLn3+, compound can be acted aspromoter of Sb2O3 in the stage ofpolycondensation. The mechanismof esterification and polycondensation by addition of Ln3+ was discussed. The thermal-stabilities ofpolyethylene terephthalate and itscopolyesters obtained by addihon ofLn3+ were also investigaed.
展开▼
机译:studies on asymmetric syntheses of Benzophenanthridine alkaloids and the Related spiro Compounds: studies on Chelidonine synthesis and Total synthesis of arnottins I and II