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The first synthesis of a polyurethane by frontal polymerization has been successfully carried out. Namely, the two reactants (1,6-hexamethylene diisocyanate and ethylene glycol) and the catalyst (dibutyltin dilaurate) were mixed together at room temperature in the presence of an additive (pyrocatechol, necessary for extending pot life), dimethyl sulfoxide (as the solvent), and a filler (fumed silica, added for stabilizing the propagating front). The reactions were thermally ignited at one end of the tubular reactor, and the resultant hot fronts were allowed to self-propagate throughout the reaction vessel. The effects of relative amounts of the above components on the most relevant parameters relating to frontal polymerization (temperature profile, front velocity, and temperature) were thoroughly investigated.

Anionic poly ( -caprolactam), isothermally synthesized at temperatures between 155 and 195 °C by very fast carbamoyl-type activators, has been characterized by UV, DSC, and wide-angle X-ray scattering (WAXS) techniques in terms of high polymer yield, irregular structures along the chain, extent of cross-linking, Tg and Tm values, degree of crystallinity, and polymorphism. The specific role of four different activators on the above properties has been compared. From the whole set of characterization data it is evident that cyclohexylcarbamoylcaprolactam behaves as the most suitable activator and provides poly( -caprolactam) with properties that favorably match those of the corresponding hydrolytic polyamide.

The structure of hyperbranched aromatic polyamides synthesized from different ratios of p-phenylenediamine and trimesic acid (A2 + B3 reagent pair) has been investigated by means of 1 H and 13 C NMR spectroscopy. On the basis of a detailed NMR signal assignment six 1,3,5-trisubstituted benzene moieties with different substitution patterns can be distinguished. The different monomer ratios influence the polymer architecture with respect to the content of these substructures, the degree of branching and the predominant functionalities (COOH or NH2). An excess of B3 results in a larger number of branches and a predominant COOH functionalization. 1 H NMR proves site-specific interactions between lithium cations and the polymer substructures. The observed chemical shift effects simplify the quantification of the spectra. Finally, acetylation of amino groups by acetic acid, an impurity in commercial trimesic acid, could be proven.

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Interpenetrating polymer networks made of dicyclopentadiene and methyl methacrylate or tri(ethylene glycol) dimethacrylate have been successfully prepared by non-interfering frontal polymerization. The role of catalyst and free radical initiator relative amounts, as well as of monomer ratio, has been thoroughly studied. The conditions under which a pure frontal polymerization occurs, and the related values of both front velocity and maximum temperature reached by the reaction, are presented and discussed.

Frontal polymerization, a method that allows to convert a monomer into a polymer exploiting the exothermicity of the self-same polymerization reaction, has been conveniently used for the easy and fast preparation of epoxy resin-montmorillonite nanocomposites. The obtained materials have shown characteristics similar or even better than those prepared by the conventional polymerization routes. The synthetic methods and the thorough characterization of the obtained nanocomposites are described.

Hyperbranched aromatic polyamides (pPDT) from A 2 (p-phenylene diamine)+ B 3 (trimesic acid) reactants have been prepared using direct polycondensation in solution. The influence of various polymerization parameters on the polymer structure development and the sol content, as well as on gel formation, has been thoroughly investigated. Prior to the attainment of the gel point, whose occurrence is linked quite strongly to the reaction conditions, the resultant hyperbranched polymers are fully soluble even at room temperature, not only in concentrated H 2 SO 4 , but also in aprotic polar solvents (DMF, NMP, DMAc, DMSO). At 80 • C, under typical experimental conditions, gel formation starts just under 120 min. At a higher temperature (115 • C), the attainment of crosslinking reactions is accelerated (gel point occurs at about 20 min). Both the presence of added salt (LiCl) to the reaction medium at 80 • C and the use of highly purified reagents promotes earlier gel occurrence. By increasing the molar ratio of primary amino to carboxyl groups from two-thirds to one, the network formation is delayed. A molar ratio of 1/2 leads to the formation of oligomers only.Both the polymer structure development and the degree of branching of pPDT have been evaluated by NMR spectroscopy as functions of reaction conditions. As compared to pPDT, polymers prepared from the homologous AB 2 monomer show similar intrinsic viscosity and glass transition temperature, but higher molecular weights and distinct differences in the relative ratio of the various structural units. The lyotropic and thermotropic behaviour of both polymers has been found.