Abstract:

The sequential structures and monomer unit ratio of ethylene-propylene copolymer(EPC)were analyzed by FTIR, ¹ H NMR and ¹³ C NMR. The spectra of ¹ H NMR, ¹³ C NMR and two-dimensional NMR of EPC were also analyzed in detail, the differential explanations of the NMR spectra for EPC with predecessors, and an analytical method of the relativity of the integrated areas of differential carbon atoms in the inverse gated decoupling ¹³ C NMR spectrum were proposed in this paper. The proposed method can be used to determine the main sequential structures in EPC simply. The theoretical calculated results of the main sequence distribution for three EPR samples proved that the proposed method is feasible.Compared ¹ H NMR with ¹³ C NMR, it is accepted that ¹ H NMR method can be used to calculate the monomer unit ratio of ethylene and propylene in EPC.

Key words: NMR spectrum; FTIR spectrum; Ethylene-propylene copolymer; Sequential structure; Monomer unit ratio