Nature Chem. http://doi.org/kpj (2013)

Credit: © 2013 NPG

Aligning linear polymer chains in a crystalline-like manner is synthetically challenging but may result in enhanced mechanical and thermal properties. Susumu Kitagawa and colleagues now report the uniaxial alignment of atatic polystyrene to form a pseudo-crystalline arrangement using porous coordination polymers (PCPs) as host materials. The PCPs are functionalized with bifunctional molecules that crosslink the polystyrene chains as they form within the channels of the porous host (pictured). When the PCP matrix is selectively removed, highly aligned polystyrene with a defined distance between chains, is obtained. The polystyrene forms shape-replicas of the cubic PCP crystals, indicating that polymerization is limited to within the porous crystals. In comparison with other alignment methods that rely on weaker interactions between chains, the covalent nature of the crosslinks imparts structural stability on the polymer when exposed to heat and organic solvents. The cross-polymerization of methyl methacrylate was achieved by the same route, demonstrating the extension of the method to other radical vinyl monomers.