Akihiko Nakano

Non-catalysed polymerization of acrylamide

Abstract It was found that acrylamide which had been left standing in air for several weeks polymerized spontaneously in water at room temperature at a rapid speed of polymerization in spite of the absence of an initiator. Poly(acrylamide peroxide) was found in acrylamide that had stood for a long time and in acrylamide that had been irradiated with daylight, while no peroxide was found in propion amide. These results seem to show that the above spontaneous polymerization was initiated by the peroxide which was formed in the acrylamide monomer. The formation of the peroxide was promoted by light and its decomposition was promoted by the addition of water. The polymerization of acrylamide was carried out by using the separated poly(acrylamide peroxide). The rate of polymerization increased with increase in the water content, but was slow in solvents containing other polar solvents such as halide solvents and alcohols. No polymer was obtained when a little picric acid was added. When acrylamide was polymerized in water with the peroxide, the rate of polymerization was found to be proportional to the monomer concentration and to the square root of the peroxide concentration. This peroxide also initiated the polymerization of methacrylic acid in water to produce a block copolymer.

Non-catalyzed Polymerization of Acrylamide

空気中に保存したアクリルアミドは, 室温付近の温度で, 通常の開始剤を加えないでも溶液中で速やかに重合することが認められた。これは, アクリルアミドが空気中の酸素と反応して重合体の形のペルオキシドを生成し, ラジカル重合を開始することによるととがわかった。このペルオキシドの生成は光により促進された。また分解は水の添加により促進されることがわかった。この重合体の形のペルオキシドを用いてブクリルアミドの重合を行なった。水の存在は重合を促進したが, 他の極性溶媒( 含塩素溶媒, アルコールなど) では促進されなかった。水を溶媒とした時, 重合速度はモノマー濃度の1 乗, ペルオキシド濃度の1 / 2乗に比例することを認めた。このペルオキシドは水を溶媒にして, メタクリル酸の重合を開始し, ブロック共重合体を生成した。