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In step-growth polymerization, the Carothers equation (or Carothers' equation) gives the degree of polymerization, ''X''n, for a given fractional monomer conversion, ''p''. There are several versions of this equation, proposed by Wallace Carothers who invented nylon in 1935. ==Linear polymers: two monomers in equimolar quantities== The simplest case refers to the formation of a strictly linear polymer by the reaction (usually by condensation) of two monomers in equimolar quantities. An example is the synthesis of nylon-6,6 whose formula is ()n from one mole of hexamethylenediamine, H2N(CH2)6NH2, and one mole of adipic acid, HOOC-(CH2)4-COOH. For this case〔Cowie J.M.G. "Polymers: Chemistry & Physics of Modern Materials (2nd edition, Blackie 1991), p.29〕〔Rudin Alfred "The Elements of Polymer Science and Engineering", Academic Press 1982, p.171〕 : In this equation : * is the number-average value of the degree of polymerization, equal to the average number of monomer units in a polymer molecule. For the example of nylon-6,6 (n diamine units and n diacid units). : * is the extent of reaction (or conversion to polymer), defined by : * is the number of molecules present initially as monomer : * is the number of molecules present after time t. The total includes all degrees of polymerization: monomers, oligomers and polymers. This equation shows that a high monomer conversion is required to achieve a high degree of polymerization. For example, a monomer conversion, ''p'', of 98% is required for , and ''p'' = 99% is required for . 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Carothers equation」の詳細全文を読む スポンサード リンク
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