Photograft copolymerization of methyl methacrylate on silk fiber using titanium(III) chloride-potassium persulphate redox initiator in a limited aqueous system. I

Abstract

Graft copolymerization of methyl methacrylate (MMA) onto mulberry silk fibers has been investigated in a limited aqueous system employing titanium(III) chloride-K 2 S 2 O 8 as the redox initiator under a photoactive condition with visible light. Polymerization in the presence of light at 32 Ϯ 1°C has been found to be more pronounced than in the dark under identical conditions. The percentage of grafting, the percentage of total conversion, and the percentage of grafting efficiency have been studied by varying the reaction time, concentration of monomer, initiator concentration, solvent composition, and pH of the medium. A high percentage of grafting (ϳ 93%), high grafting efficiency (ϳ 97%), and the percentage of total conversion (ϳ 25%) have been obtained with little homopolymer formation. Characterization of the grafted fibers has been investigated by Fourier transform infrared spectroscopy and scanning electron microscopy. Finally, the reaction mechanism has been discussed by considering hydrogen bonding.

Optimized conditions for the grafting reaction of poly(methyl acrylate) onto rubberwood fiber

“…Graft copolymerization of RWF with various MA concentrations was carried out at 50 °C for 1 h. It was observed that the degree of grafting increased as the monomer amount was increased in the grafting reaction, and reached 187% at 0.05 mol of MA, as shown in Fig 7. The increase of grafting percentage could be due to the increase in grafting rate22 and the gel effect 23…”

Graft copolymerization of methyl methacrylate onto rubber‐wood fiber using H2O2 and Fe2+ as an initiator system

“…It was observed that the degree of grafting increased as the monomer amount was increased in the grafting reaction, reaching 82.4% at 2.36 × 10 −2 mol of MMA, as shown in Figure 5. The increase of grafting percentage may be a consequence of the increased grafting rate19 and the gel effect 20…”

Studies of mechanical and moisture regain properties of methyl methacrylate grafted silk fibers

“…Hence, the solvents do not have much of an affect on the fiber orientation before and after have grafting. Whenever the grafting reaction is conducted in their presence, the tenacity remains almost unchanged because it is a function of the fiber orientation 11…”