The poly(n-hexyl isocyanate), poly(p-tolyl isocyanate), and copoly(n-hexyl-p-tolyl isocyanate) which contains 16 mole percent of p-tolyl isocyanate content have been prepared by low temperature anionic polymerization in dimethyl formamide. Narrow-distribution fractions of each polymer species were obtained by carefully controlled successive fractional precipitation method. Number average molecular weight(Mn) and osmotic second virial coefficients were determined by osmometry in toluene at 37℃. The intrinsic viscosity behaviors of each series of polymer fractions have been examined over the molecular weight range of 2.9*10⁴ to 7.3*10⁵ g/mole in toluene, chloroform, and tetrahydrofuran at 25℃, as well as under theta conditions. Thetatemperatures of 16.4℃ for poly(n-hexyl isocyanate), 14.8℃ for poly(p-tolyl isocyanate), and 13.2℃ for the copolymer of n-hexyl and p-tolyl isocyanate were obtained from the phase separation studies in toluene. The unperturbed molecular dimensions in dilute toluene solution have been determined by a number of extrapolation methods for data at 25℃. The value of short-range interaction parameter, A=(2>₀/Mn)^1/2, of copolymer was found as 1.200*10^-8cm·mol^1/2/g^1/2. This was comparable with the value obtained for poly(p-tolyl isocyanate), 1.114*10^-8, but was found to be far below than that of poly(n-hexyl isocyanate), 3.24*10^-8. The molecular shape of copolymer in toluene at theta condition, therefore, was estimated as a interrupted helix structure with short blocks of n-hexyl isocyanate units.

저온 음이온 중합법에 의하여 n-Hexyl isocyanate 단중합체, p-Tolyl isocyanate 단중합체 및 p-Tolyl isocyanate 함량이 16몰 퍼센트되는 n-Hexyl isocyanate 공중합체를 합성하였다. 이들 각 중합체들을 연속식 재 침전 방법으로 분자량분포가 비교적 좁은 분별물로 분별하였다. 각 분별시료에 대하여 수평균분자량(Mn)과 제2 virial 계수(A²)를 37℃에서 삼투압 측정으로 결정하였다. 분자량 2.9*10⁴에서 7.3*10⁵g/mole에 해당되는 분별시료들의 극한 점도를 Toluene, Chloroform, Tetrahydrofuran 등을 용매로하여 θ-온도 및 25℃에서 측정하였다. Toluene을 용매로 하는 상분리 실험을 하여 n-Hexyl isocyanate 단중합체의 θ-온도가 14.8℃ 및 공중합체의 θ-온도가 13.2℃임을 밝혔다. 25℃에서의 극한 점도값 및 37℃에서의 제2 virial 계수값들을 기초로하여 몇가지 외삽법에 의한 수단으로 각 중합체의 Toluene중에서의 이상분자 크기를 결정 비교하였다. 공중합체의 단거리 상호작용 Parameter 값은 1.200*10^-8cm·mole^1/2/g^1/2로 밝혀졌으며 이것은 p-Tolyl isocyanate 은중합체의 값과 비슷하였고 n-Hexyl isocyanate 단중합체 값보다는 훨씬 적은 것으로 나타났다. 이들 결과와 공중합체의 반응성 비의 값들로부터 n-Hexyl-p-Tolyl isocyanate 공중합체의 Toluene중 이상분자 형태가 n-Hexyl 단위가 짧게 연결된 Interrupted helix 구조인 것으로 추정되었다.