PARTIAL CARBAMOYLATION OF CELLULOSE MICROSPHERES: A NEW METHOD TO PREPARE ADSORBENTS FOR LIQUID CHROMATOGRAPHY

摘要

Micron-sized cellulose microspheres were prepared through sol-gel method using NaOH/urea solution to dissolve cellulose,then cross-linked by 1,6-hexanylene diisocyanate(HDI),toluene 2,4-diisocyanate(TDI)and 1,4-phenylene diisocyanate(PDI),respectively.The reaction conditions for partial modification of the microspheres were studied.The degree of substitution(DS)in cellulose was controlled by adjusting the reaction conditions.HDI-crosslinked microspheres were partially modified with phenyl isocyanate to obtain chiral stationary phases(CSPs).The CSPs of a lower degree of crosslinking(DC)showed better chiral recognition ability than those of a higher DC.Meanwhile the CSPs prepared by premodification exhibited better chiral recognition ability than those prepared by pre-crosslinking.