Study of the effect of reaction variables on grafting of acrylic acid onto carboxymethyl chitosan

摘要

Carboxymethyl chitosan (CMCH) was prepared and characterized by FT-IR spectroscopy. Grafting of acrylic acid (AA) onto CMCH using ceric ammonium nitrate (CAN) as an initiator was carried under nitrogen atmosphere in aqueous solution. Evidence of grafting was confirmed by comparing the FT-IR spectra of CMCH and the grafted co-polymer, as well as scanning electron microscopy (SEM) and X-ray diffraction of the products. The effects of concentration of CAN, concentration of acrylic acid, reaction time and temperature on graft co-polymerization were studied by determining the grafting percentage, grafting efficiency, percentage add-on and percentage total conversion. Keeping the other conditions constant, the optimum grafting conditions were obtained as follows: CMCH = 2 g, CAN = 0.2 M and AA = 0.729 M, reaction temperature = 35°C and reaction time = 4 h.