Abstract: To improve the mechanics properties of polyurethane materials at a high or low temperature, a hydroxy compound N-100 of HDIwas synthesized.The structure analysis and characterization were made by NMR (¹H, ¹³C, ¹H-¹H COSY, ¹³C-¹H COSY).In addi-tion, quantitative description of the network was made on the basis of some ideal assump-tions.1Dand 2D NMRcan differentiate four sorts of carbonyl groups and establish the con-nections of all carbon and hydrogen atoms of mixed structures that originated from five dif-ferent substitutions.Besides, the alkene and isocyanate, urea, biuret and trimerized isocya-nuric groups were also detected.Therefore, the structure of N-100 was suggested be a poly-isocyanate with complicated network which contained nitrogen atom as cross-linkage, iso-cyanate and alkene as end groups.The consistence of calculated values with tested values of isocyanate content, mean function degree and mean molecular weight demonstrated the cor-rect of structure characterization and the validity of network description.

Key words: N-100, Structure analysis and characterization, 1D NMR (¹H,¹³C), HDI, Curing agent