Crosslinking of dextran with some selective Cl-, P- and N-containing functional substances.pdfVIP

Reactive Functional Polymers 47 (2001) 55–65 /locate/react Crosslinking of dextran with some selective Cl-, P- and N -containing functional substances in aqueous solutions ¨ * ¨ 1 Ali Guner , Ozlem Akman, Zakir M.O. Rzaev Department of Chemistry, Faculty of Science, Hacettepe University, Beytepe, 06532 Ankara, Turkey Received 4 February 2000; received in revised form 20 October 2000; accepted 31 October 2000 Abstract Crosslinking reactions of Dextran (Dx) (Mn of 5.0 105 and 2.0106 g mol1 ) with some selective Cl-, P- and N -containing functional monomers such as epichlorohydrin (ECH), phosphorus oxychloride (POC1 ) and N,N -methyl- 3 enebisacrylamide (MBAM) as well as with 60Co--irradiation were carried out in the basic aqueous solutions (2.8 N NaOH) at 25–50C. The optimum conditions of the effective swelling and crosslinking for the each system studied were found. Some swelling parameters such as initial rate of swelling (R S , %min1), crosslink density (, g ml1), equilibrium swelling (S , %) and average molecular weight of crosslinked fragments (M , g mol1) for the Dx/crosslinker (CL) systems studied eq c were determined by using of kinetic methods and well known Flory-Rehner equation. A substantial difference of these parameters observed for the various Dx/CL systems was explained by the effect of nature