TY - JOUR
T1 - Phase behavior of a weakly interacting polystyrene and poly(n-hexyl methacrylate) system
T2 - Evidence for the coexistence of UCST and LCST
AU - Ahn, Hyungju
AU - Naidu, Sudhakar
AU - Ryu, Du Yeol
AU - Cho, Junhan
PY - 2009/3/19
Y1 - 2009/3/19
N2 - The phase behavior of a weakly interacting binary system composed of deuterated polystyrene (dPS) and poly(n-hexyl methacrylate) (PnHMA) was investigated by the turbidity measurement for the binary blend, and by small angle X-ray scattering (SAXS) and depolarized light scattering for the block copolymers. For the binary dPS/PnHMA blend, a new phase diagram involving both the upper critical solution transition (UCST) and lower critical solution transition (LCST) was observed by the delicate control of molecular weights between dPS and PnHMA. Whereas for the block copolymers such as dPS-block-PnHMA and PS-block-PnHMA, an order-to-disorder transition (ODT) on heating was observed within the experimental temperature range depending on the molecular weight. This coexistence of both a UCST and LCST in the dPS/PnHMA blend consequently represents the experimental evidence that the corresponding (d)PS-b-PnHMAs possess not only ODT, but also lower disorder-to-order transition (LDOT) character driven by a compressibility difference, although the latter is hindered by thermal degradation.
AB - The phase behavior of a weakly interacting binary system composed of deuterated polystyrene (dPS) and poly(n-hexyl methacrylate) (PnHMA) was investigated by the turbidity measurement for the binary blend, and by small angle X-ray scattering (SAXS) and depolarized light scattering for the block copolymers. For the binary dPS/PnHMA blend, a new phase diagram involving both the upper critical solution transition (UCST) and lower critical solution transition (LCST) was observed by the delicate control of molecular weights between dPS and PnHMA. Whereas for the block copolymers such as dPS-block-PnHMA and PS-block-PnHMA, an order-to-disorder transition (ODT) on heating was observed within the experimental temperature range depending on the molecular weight. This coexistence of both a UCST and LCST in the dPS/PnHMA blend consequently represents the experimental evidence that the corresponding (d)PS-b-PnHMAs possess not only ODT, but also lower disorder-to-order transition (LDOT) character driven by a compressibility difference, although the latter is hindered by thermal degradation.
UR - http://www.scopus.com/inward/record.url?scp=62749090592&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=62749090592&partnerID=8YFLogxK
U2 - 10.1002/marc.200800646
DO - 10.1002/marc.200800646
M3 - Article
C2 - 21706627
AN - SCOPUS:62749090592
VL - 30
SP - 469
EP - 474
JO - Macromolecular Rapid Communications
JF - Macromolecular Rapid Communications
SN - 1022-1336
IS - 6
ER -