Interfacial polycondensation - Kaimen Juushukgo

A polymerization method in which polycondensation takes place at the interface between two liquid phases where the monomers do not mix with each other. It can be carried out while the two liquid phases are left stationary or while being stirred. The most well-known example is the synthesis of nylon from aliphatic acid chlorides and aliphatic diamines. For example, when 3.74 mL of an aqueous solution containing 4.34 g of hexamethylenediamine and 3.00 g of sodium hydroxide is gently added to a solution of 8 mL of sebacoyl chloride in 632 mL of carbon tetrachloride, a film of nylon 6-10 immediately forms at the interface, and when it is pulled up, polymerization at the interface continues and it can be wound up as a continuous rope. In this case, sodium hydroxide acts as an acid acceptor and makes the reaction smooth. In general polycondensation, the degree of polymerization does not increase unless the molar ratio of the monomers in the system is exactly equal, but in this reaction, polymerization proceeds only at the interface, so a high degree of polymerization can be achieved even if the molar ratios throughout the system are different. The continuous diffusion of monomers to the interface results in a polymer with a high degree of polymerization.

Source: Morikita Publishing "Chemical Dictionary (2nd Edition)" Information about the Chemical Dictionary 2nd Edition

重縮合をそれぞれの単量体が互いに混合しない二液相の界面で行わせる重合方法．二液相を静置したまま行う場合と，かくはんしながら行う場合とがある．もっともよく知られた例は，脂肪族酸塩化物と脂肪族ジアミンを原料としたナイロン合成である．たとえば，四塩化炭素632 mL にセバシン酸クロリド8 mL を溶かした溶液に，ヘキサメチレンジアミン4.34 g と水酸化ナトリウム3.00 g を含む水溶液3.74 mL を静かに加えると，その界面にただちにナイロン6-10の皮膜が生じ，これを引き上げると界面での重合が引き続き進行し，連続したロープとして巻きとることができる．この場合，水酸化ナトリウムは酸受容剤としてはたらき，反応を円滑にする．一般の重縮合では，系中の単量体のモル比を正確に等しくしないと重合度が大きくならないが，この反応では界面のみで重合が進行するため，系中全体でモル比が異なっていても高重合度が達成できる．界面への単量体の連続的拡散により，高重合度の重合体が得られる．

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