TY - JOUR
T1 - Interactions between polystyrenes of different tacticities and thermal evidence for miscibility
AU - Woo, E. M.
AU - Lee, M. L.
AU - Sun, Y. S.
N1 - Funding Information:
This work was generously supported by Taiwan National Science Council (NSC) with Grant No: NSC 87 CPC E006 017. The authors also remember the kindness of Mr. Masahiko Kuramoto of Idemitsu Petrochemical Co. Ltd. (Japan), who supplied the s-PS material used in this study.
PY - 2000/2
Y1 - 2000/2
N2 - Various evidence of thermal behavior was probed to discuss the miscibility in atactic polystyrene (a-PS) with syndiotactic polystyrene (s- PS), which was not trivial owing to the small difference of only 10°C between the T(g)s of these two isomeric polystyrenes. The preliminary morphology characterization using optical and scanning electron microscopies indicated that no discernible heterogeneity existed in the a-PS/s-PS blend. Composition dependence of peak temperature of cold crystallization for the quenched a-PS/s-PS blend samples also supported that inter-segmental interactions existed. The crystallinity of s-PS in a-PS/s-PS mixtures showed a minor negative deviation from linearity, which suggests favorable, albeit weak, interactions between the chain segments of s-PS and a-PS. These results provide evidence that this isomeric pair of polystyrenes of different tacticities are mixed in the molecular scales. The melting behavior of semicrystalline s-PS in the a-PS/s-PS mixtures was analyzed using the Flory- Huggins approach. In measuring the equilibrium melting point of s-PS in the a-PS/s-PS mixtures, the complex multiple melting peaks of s-PS were also discussed. A small negative value for the interaction parameter (X=~-0.11) was found, further suggesting that miscibility is likely favored.
AB - Various evidence of thermal behavior was probed to discuss the miscibility in atactic polystyrene (a-PS) with syndiotactic polystyrene (s- PS), which was not trivial owing to the small difference of only 10°C between the T(g)s of these two isomeric polystyrenes. The preliminary morphology characterization using optical and scanning electron microscopies indicated that no discernible heterogeneity existed in the a-PS/s-PS blend. Composition dependence of peak temperature of cold crystallization for the quenched a-PS/s-PS blend samples also supported that inter-segmental interactions existed. The crystallinity of s-PS in a-PS/s-PS mixtures showed a minor negative deviation from linearity, which suggests favorable, albeit weak, interactions between the chain segments of s-PS and a-PS. These results provide evidence that this isomeric pair of polystyrenes of different tacticities are mixed in the molecular scales. The melting behavior of semicrystalline s-PS in the a-PS/s-PS mixtures was analyzed using the Flory- Huggins approach. In measuring the equilibrium melting point of s-PS in the a-PS/s-PS mixtures, the complex multiple melting peaks of s-PS were also discussed. A small negative value for the interaction parameter (X=~-0.11) was found, further suggesting that miscibility is likely favored.
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U2 - 10.1016/S0032-3861(99)00247-5
DO - 10.1016/S0032-3861(99)00247-5
M3 - Article
AN - SCOPUS:0034142608
SN - 0032-3861
VL - 41
SP - 883
EP - 890
JO - polymer
JF - polymer
IS - 3
ER -