From the spectra of the composites with diisocyanates treated, the amide band of urethane bond appeared at 1520–1530 cm1, which indicated that the reaction between –OH and –NCO groups took place [18].
From the spectraof the composites with diisocyanates treated, the amide band ofurethane bond appeared at 1520–1530 cm1, which indicated thatthe reaction between –OH and –NCO groups took place [18].