セリウム(IV)イオンによるビニルモノマー/セルロースグラフト共重合:還元性末端基の重合開始能
1979 年 35 巻 12 号 p. T512-T519
詳細
1979 年 35 巻 12 号 p. T512-T519
Graft Copolymerization of styrene onto cellulose (cellophane) has been made in the absence of mineral acid with aqueous solutions of Ce (NO3)6•2NH4(CAN) as an initiator to look for the grafting site in cellulose. In advance of the polymerization experiment, the oxidation process of cellulose with Ce4+ was traced by determining the consumption of Ce4+ due to reduction. A stoichiometric relation was found for the ratio of the number of reducing endgroups contained in cellulose sample to that of Ce4+ consumed, i.e. 1:2. Ce4+ consumption was drastically decreased for a cellulose sample in which C1-C2 glycols had been blocked by oximation. These results implied that the initial oxidation attack took place mainly on C1-C2 glycols in the reducing endgroups. In agreement with this implication, graft copolymerization did proceed only under the condition that the C1-C2 glycol was retained to be intact without suffering any chemical modification. On the basis of these experimental results it is concluded that the graft copolymerization is initiated mostly by free radicals produced at the C1-C2 glycols in the reducing endgroups, so far as the oxidation condition is mild.
