Cocrystallization of Syndiotactic Polystyrene by a Guest Exchange Phenomenon: Investigation of the Mechanism and Preparation of Polymer Composites

Syndiotactic polystyrene (sPS) is a relatively new commodity polymer, which exhibits a variety of solid states. One of the important characteristics of sPS is the formation of co-crystals, where a variety of chemical compounds can be stored as guests in the cavities between sPS helices of (T(2)G(2))(2) conformation. The guest molecule can be exchanged with other chemical compound by exposing a sPS co-crystal film to a vapor, a liquid or a solution of the new guest molecule. In particular, the addition of an additive to a liquid of the new guest molecule promotes the guest exchange process and facilitates the incorporation of bulky molecules into the crystalline region of sPS co-crystals. It has been reported that a variety of compounds including functional molecules can be incorporated into the sPS lattice by using this additive assisted guest exchange phenomenon. In this paper, we show at first that polyethylene glycol dimethyl ethers, which far exceed previous guest molecules in molecular weight, can be incorporated into the crystalline region of sPS co-crystals. Next, we review the results of ATR FT-IR spectroscopy and small angle neutron scattering experiments of the guest exchange process.