Graft copolymerization of methyl methacrylate (MMA) onto silk using potassium peroxydiphosphate–cysteine (PP–Cys) redox system

Poly(methyl methacrylate) has been grafted onto mulberry silk in an aqueous medium by using potassium peroxydiphosphate–cysteine (PP–Cys) redox initiator. Various effects upon grafting such as concentration of cysteine, concentration of peroxydiphosphate, concentration of monomer, concentration of sulfuric acid, and temperature were studied. At a low range of cysteine concentration (6.25 × 10 −4 mol/L), the rate of polymerization R p (%/s) is proportional to cysteine concentration and the exponent is calculated to be 0.8. The monomer exponent is calculated to be unity up to the concentration of 65.72 × 10 −2 mol/L. From the Arrhenius plot of log R p vs. 1/ T ( T = absolute temperature) the overall activation energy is computed to be 15.19 kcal/mol. A suitable kinetic path has been pictured and a rate expression has been derived.