title: Syndiotactic poly(N-n-propylacrylamide) shows highly cooperative phase transition.
abstract: Syndiotactic poly(N-n-propylacrylamide)s (PNNPAM) with various racemo (r) diad contents were synthesized, and their phase transition behaviors were studied by high-sensitivity differential scanning calorimetry and FT-IR spectroscopy. The cooperativity of the phase transition increased with the increase in the r diad content. Compared with the atactic PNNPAM, the number of cooperative units, which shows the monomeric units length undergoing cooperative phase transition, increased 2.5- to 4-fold in the syndiotactic polymers. From the results of FT-IR spectroscopy and quantum chemical calculations, it was determined that the high cooperativity of the syndiotactic polymers resulted from local formation of an ordered structure in a dehydrated state.
authors.affiliation: Department of Applied Chemistry, Center for Future Chemistry, and Institute for Material Chemistry and Engineering, Kyushu University, 744 Moto-oka, Nishi-ku, Fukuoka 819-0395, Japan. moritcm@mbox.nc.kyushu-u.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Mori
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Hirano
authors.forename: Atsushi
authors.initials: A
authors.lastname: Maruyama
authors.forename: Yoshiki
authors.initials: Y
authors.lastname: Katayama
authors.forename: Takuro
authors.initials: T
authors.lastname: Niidome
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Bando
authors.forename: Koichi
authors.initials: K
authors.lastname: Ute
authors.forename: Shinji
authors.initials: S
authors.lastname: Takaku
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Maeda