Nitration of soft wood pulp board

The morphology and aggregated structure of soft pulp and the nitration of soft wood pulp board were investigated by SEM, XRD and micropolariscope. The results show that the soft wood pulp has lower crystallinity and looser morphology than refined cotton. Diffusion rate of different nitration reagent to soft wood pulp board is various. Compared with HNO₃-H ₂SO₄-H₂O mixture, the diffusion rate of HNO₃-CH₂Cl₂ mixture is fast. The reaction of soft wood pulp board with HNO₃-CH₂Cl₂ is a second order reaction. The homogeneity and nitrogen content of product increase with the increase of time,considering that 40 minutes is appropriate reaction time. The nitration reaction contains two steps and each step has its own rate constant. The first rate constant is about twoorder of magnitude larger than the second one.