The aim of this study was to synthesize and characterize the self-assembly of a new family of bridged silsesquioxanes containing a pendant hydrophobic chain in the organic bridge. The precursor of this hybrid was obtained by the reaction of glycidoxypropyl(trimethoxysilane) (GPMS) (2 mol) with dodecylamine (1 mol). Polycondensation was produced with formic acid, either in mass or using tetrahydrofuran or isopropanol as solvents. The resulting bridged silsesquioxane was characterized by the presence of both ordered and disordered domains. Experimental evidence obtained from SAXS, WAXS, 29Si NMR, FTIR, HRTEM, and SAED techniques suggested that the basic structure of ordered domains consisted of hybrid organic−inorganic multilayers separated by hydrophobic regions with a thickness equal to the length of a tail-to-tail association of dodecylamine chains in all-trans conformations. To our knowledge, this is the first example of the presence of this kind of structure in a cross-linked hybrid material. A hierarchical organization of ordered domains into semicylindrical shells was observed in a microscopic scale. Because of the presence of pendant hydrophobic chains, the precursor of this hybrid material may be used for the dispersion of hydrophobic molecules or of nanoparticles stabilized by hydrophobic chains.

Block copolymer (BCP)/epoxy blends have been intensively investigated during the past decade. Macrophase separation of the BCP in the cured thermoset is avoided by selecting one block that is initially immiscible or that phase separates early in the polymerization and another block that remains miscible up to high conversions. But the quality of the thermoset as a solvent of the miscible block varies along the cure cycle with both conversion and temperature. It shifts from a good solvent to a poor solvent, and eventually to a nonsolvent, by increasing conversion mainly due to the increase in the average molar mass before gelation and the cross-link density after gelation. It also changes with temperature due to the corresponding variation of the interaction parameter. Therefore, for a constant BCP concentration different nanostructures might be accessed and fixed by changing the cure cycle. This can be of interest to modulate final properties of the material (e.g., toughness, transparency, etc.). The selected system to prove this concept was a solution of 20 wt % PS-b-PMMA (M n = 67 100, ΦPS = 0.69) in a stoichiometric mixture of diglycidyl ether of bisphenol A (DGEBA) and 4,4′-methylenebis(2,6-diethylaniline) (MDEA). Generated nanostructures varied with the selected cure cycle from a dispersion of spherical micelles to a dual morphology consisting of domains of hexagonally packed cylinders and regions with a dispersion of spherical micelles. This produced changes in transparency and in dynamic-mechanical properties of the resulting nanocomposites.