Ordering in self-organizing comb copolymer-like systems obtained by hydrogen bonding between charged or noncharged polymers and amphiphiles

Mesomorphic structures and order–disorder transitions in comb copolymer-like systems obtained by hydrogen bonding of noncharged or charged homopolymers with amphiphiles are discussed. The amphiphiles consist of attractive and repulsive moieties and the emphasis will be on the situation without an additional solvent phase. Poly(4-vinyl pyridine), i.e. P4VP, hydrogen bonded to stoichiometric amounts of pentadecylphenol (PDP) is one of the characteristic examples. Small angle X-ray scattering and dynamic rheology demonstrate that this system forms a disordered melt at temperatures above the order-disorder temperature (TODT), whereas for T < TODT a lamellar microphase separated structure is observed. Further cooling renders side chain crystallization. This phase behavior can be tailored by adjusting the attraction and the repulsion between the amphiphile and the polymer. Repulsion can be increased by making the alkyl chain longer or by adding charges to the backbone. Both lead in general to a higher TODT. Order-disorder transitions can occur even in polyelectrolyte-amphiphile complexes as is demonstrated by first fully complexing P4VP with toluene sulphonic acid (TSA) to form a polymeric salt P4VP(TSA)1.0 which is further hydrogen bonded to PDP. The presented results offer guidelines to apply the concepts to other polymers as well, with an example mentioned in relation to polyamide 6.