Abstract
To study the formation of polycomplex between poly (vinyl alcohol) (I) and poly (methacrylic acid) (II) heat of mixing (Q) of I and II in aqueous solution was measured with a microcalorimeter. Q-composition curves (up to the equimolar mixture) were much different according to whether II was added to I (mixing I-II) or the addition was reversed (mixing II-I), This can be interpreted as follows: in the former case, II. added portionwise is subjected to change the conformation in every step but, in the latter the conformational transition of II is ended in early stages of I-addition with a fair heat absorption. II may conformationally transform under the cooperation of I. Estimated heat of mixing at 1: 1 base-molar ratio of I and II was -265±10J/mol irrespective of the order of mixing. I and II may also exist in complex state at 2: 1 and 1: 2 compositions.
