Supramolecular side chain liquid crystal polymers II. Interaction of mesogenic acids and amorphous polymers

Poly(N‐vinylimidazole) based hydrogen bonded side chain liquid crystalline polymer

“…Side chain liquid‐crystalline polymers (LCPs) are usually prepared by covalently linking rigid mesogens to a polymer backbone through flexible spacers. In recent years, self‐assembly through specific interactions, such as hydrogen‐bonding13–15 ionic, ionic‐dipolar, and charge transfer interactions,13 has been recognized as a new strategy for constructing SCLCPs. Self‐assembled materials formed by non‐covalent bonding have attracted much attention because these materials are good candidates for the next generation of materials16–26 for which dynamic function, environmental compatibility, and low energy processing are required.…”

“…Carboxylic and benzoic acid groups are widely used as H‐bond donors while pyridine moieties are commonly used as H‐bond acceptors. Complexes obtained through intermolecular H‐bonding include systems consisting of derivatives of carboxylic (or benzoic) acid/pyridine,13–21 carboxylic acid/2,6‐diaminopyridine,22, 23 uracil/2,6‐diaminopyridine,24, 25 and carboxylic acid/pyridine N ‐oxide 26…”

Synthesis of chalcone‐containing methacrylate‐based hydrogen bonded side chain liquid crystalline polymer and its dielectric properties

“…Side chain liquid‐crystalline polymers are usually prepared by covalently linking rigid mesogens to a polymer backbone through flexible spacers. In recent years, self‐assembly through specific interactions, such as hydrogen‐bonding ionic, ionic dipolar and charge transfer interactions, have been studied …”

Supramolecular Side-Chain Liquid Crystalline Polymers with Various Kinked Pendant Groups

“…The function of the spacers is to decoupling the motion of the polymer backbones from the self-ordering of the mesogens. Nevertheless, instead of linking pendant groups covalently to the side chains of the polymers, novel mesogenic properties can also be easily obtained through the noncovalent linkage (i.e., hydrogen bond), and thus the hydrogen-bonded side-chain liquid crystalline polymers are of special interest to several research laboratories. − Among their approaches, intermolecular hydrogen bonding is easily obtained by complexation of carboxylic (or benzoic) acid and pyridyl moieties. Several series of H-bonded complexes and side-chain liquid crystalline polymers through intermolecular hydrogen bonding (between benzoic acid and pyridyl interactions) have been reported lately. − …”

“…Supramolecular side-chain liquid crystalline polymers (monomer−polymer complexes) may contain both or either (or even neither) constituents (polymers and pendant monomers) possessing liquid crystallinity; however, the liquid crystallinity can be generated or can be altered through hydrogen bonding. Supramolecular side-chain polymers that contain hydrogen bonds located near the polymer backbones of the side-chain polymers have been reported recently. − To prove the existence of this kind of supramolecular side-chain polymer, different proton donors, i.e., acids ( 1 − 3 ), were complexed not only with poly(4-vinylpyridine) (P4VP) but also with poly(2-vinylpyridine) (P2VP) (or with polystyrene). − However, similar thermal behavior of these complexes, which contain either P4VP or P2VP with acids ( 1 − 3 ), suggested that limited miscibility of the proton acceptors and the acids has occurred. Few supramolecular side-chain polymers have formed in these types of complexes, though various degrees of hydrogen bonding between poly(vinylpyridines) (P4VP or P2VP) and proton donors (acids or alcohols) were reported in the literature. − It was also demonstrated that in order to construct the supramolecular side-chain liquid crystalline polymers by connecting the monomers to the polymer backbones noncovalently, the strength of the hydrogen bond should be large by using complementary units containing multiple binding sites to prevent proton transfer.…”