SUBSTITUENT CHEMICAL SHIFT (SCS) AND THE SEQUENCE STRUCTURE OF ETHYLENE-VINYL ALCOHOL COPOLYMERS

摘要

Three ethylene-vinyl alcohol copolymers were studied by means of the substituent chemical shift （SCS） method. The SCS parameters of hydroxy （-OH） in two different solvents were obtained: in deuterium oxide/phenol （20/80 W/W ） the parameters are S₁ = 42.77±0.08ppm, S₂ = 7.15±0.06 ppm, S₃ （s）= -4.08±0.02ppm, S₃ （t） =-3.09±0.20ppm,S₄ = 0.48±0.03ppm, S₅ = 0.26±0.05ppm. In o-dichloro-benzen-d₄ S₁（s）=44.79±0.61ppm, S₂=7.40±0.00ppm, S₃（s）=-4.51±0.17ppm, S₃（t）=-3.13 ±0.00 ppm, S₄ =0.63±0.04ppm, S₅=0.36±0.00ppm.Simultaneously the 13CNMR spectra of EVA copolymers were assigned by using the SCS parameters obtained.