Study on complexing behavior of the syndiotactic polystyrene- aromatic hydrocarbon system Yusuke Yamamoto*, Devaraj Amutharani, Muthusamy Sivakumar, Yoshiharu Tsujita, Hiroaki Yoshimizu Department of Materials Science and Engineering, Nagoya Institute of Technology,Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan Tel. +81 (52) 735-5272; Fax +81 (52) 735-5272, email: yosimizu@mse.nitech.ac.jp Received 4 February 2002; accepted 21 March 2002 Desalination 148 (2002) 289–291 Presented at the International Congress on Membranes and Membrane Processes (ICOM), Toulouse, France, July 7–12, 2002 0011-9164/02/$– See front matter © 2002 Elsevier Science B.V. All rights reserved *Corresponding author. 1. Introduction Synthesized syndiotactic polystyrene (sPS) is characterized by a complex formation with organic molecules, a clathrate form in which sPS chains exhibit TTGG helical conformation and the guest molecules are housed between the helical chain. Accordingly, it may be expected that organic molecules whose size and shape occupy on Abstract Guest molecular dynamics related to the stable complexing behavior of syndiotactic polystyrene (sPS)- xylene isomer (m- and p-xylene, abbreviated MX and PX) complexes have been characterized by solid-state 13 C-NMR spectroscopy. Similar chemical shifts are observed for both sPS complexes in the 13 C-CP/MAS spectrum. Interestingly, the solvent resonance of methyl carbon could be observed under CP conditions, indicating the relative rigidity of the solvent. Inversely, the sPS-MX system showed doublet peaks at 21.8 and 23.2 ppm when compared with the atactic PS-MX system, suggesting the orderly arrangement of the methyl group in the complexed system. The mobility of the guest molecule in the system is evaluated using spin-lattice relaxation time (T 1 c ). Moreover, the mobility of helical chains of sPS is also inferred from its T 1 c . Hence, the influence of the mobility of the methyl carbon of xylene and the sPS helical chain could be investigated, which helps in studying the complexing behavior of the sPS-xylene system. Keywords: Syndiotactic polystyrene; 13 C-NMR spectroscopy; Xylene isomer complex