Honeycomb structured porous films prepared from carbohydrate based polymers synthesized via the RAFT process

Carbohydrate based polystyrene was synthesized via RAFT polymerization. The RAFT agents were based on alpha-D-glucose, beta-cyclodextrin and modified cellulose to obtain polystyrene with a polar head or polystyrene with a star or comb structure, respectively. The polymerizations were carried out in different solvents. The molecular weight of the linear polymer was found to develop according to the expected values, but the synthesis of the carbohydrate based polymers was influenced by other parameters. The molecular weight for the star polymer synthesis showed a pronounced deviation due to the reduced accessibility of the RAFT group at higher conversions of the polymerization. Films of these carbohydrate containing polystyrenes were cast from carbon disulfide and dichloromethane producing highly regular honeycomb structured films with pore diameters between 0.5 and 4 mum. The pore size was influenced by the polymers used as well as by the casting conditions.