EFFECT OF L(-)THREONINE, 5-HYDROXYTRYPTOPHANE, AND 5-HYDROXYTRYPTAMINE ON THE CERIC-ION-INITIATED GRAFTING OF METHYL ACRYLATE ONTO CELLULOSE

In order to study the effect of some radio protecting agents (RPA) such as L(-)threonine, 5-hydroxytryptophane (5-HT), and 5-hydroxytryptamine on ceric-ion-initiated grafting onto cellulose, attempts have been made to graft copolymerize methyl acrylate (MA) in aqueous medium in the presence and absence of RPA. Percentage of grafting has been determined as functions of concentration of (i) ceric ion, (ii) H2SO4, (iii) monomer, (iv) RPA, (v) reaction time, and (vi) reaction temperature. Maximum grafting percentage was obtained at [MA] = 5.53 X 10(-2) mol/L within 180 min at 45-degrees-C in the absence of RPA. Grafting reactions were found to be suppressed in the presence of different RPAs. A plausible mechanism is suggested to explain the observed behavior of RPAs in grafting reactions. The graft copolymers have been characterized by IR spectroscopic and thermogravimetric methods. (C) 1993 John Wiley & Sons, Inc.