Click-dendronized poly(amide-triazole)s--effect of dendron size and polymer backbone symmetry on self-assembling and gelation properties

A photo-responsive poly(amide–triazole) physical organogel bearing azobenzene residues in the main chain

The synthesis of a click poly(amide–triazole) bearing multiple azobenzene units along the main chain was reported.

Different Gelation and Self-Sorting Properties of Two Isomeric Polyamides Owing to the Parallel versus Anti-Parallel Alignment of Backbone Dipoles

Two isomeric bottlebrush polyamides P-1 and A-1, with the same repeating monomer dipole units aligned along the polymer backbone in pseudo-parallel and pseudo-antiparallel fashion, respectively, were synthesized and characterized. Both polymers can form thermoreversible gels with aromatic solvents but P-1 was found to show inferior gelation strength compared with that of A-1. Furthermore, despite their close structural resemblance, a 1:1 mixture of the P-1 and A-1 polymers was shown to exhibit self-sorting in the gel state. Gel formation was found to be a kinetically trapped process through hydrogen bonding, π-π stacking interactions, and side chain interdigitation. The different gelation and self-sorting properties can be explained by the local dipole-dipole interactions originating from the different modes of backbone dipole alignment. In single gel systems, the antiparallel-aligned dipoles in A-1 facilitated a more compact molecular packing owing to the enthalpically more favorable polymer chain association. On the other hand, the parallel-aligned dipoles in P-1 gave rise to a less stable head-to-head packing, which had difficulties to convert to the more stable head-to-tail packing in a kinetically trapped environment. In the mixed gel system, it is the unfavorable hetero-polymer mismatch dipole-dipole interaction that inhibited the mixing of the A-1 and P-1 polymers and led to self-sorting.

Formation of long sub-chain hyperbranched poly(methyl methacrylate) based on inhibited self-cyclization of seesaw macromonomers

Well-defined hyperbranched PMMA almost without self-cyclization was obtained through a click reaction, facilitated by a high concentration, good solvent and disubstituted chain ends.

Synthesis of novel series of malonamides derivatives via a five-component reaction

A one-pot, five-component condensation reaction of isocyanide, Meldrum's acid, arylidene malononitrile, and two amine molecules in CH2Cl2 at ambient temperature to give malonamide derivatives is described.