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This article studies the diversification of useful properties of polyurethane (PU) structures by the inclusion of new components. PUs containing a Schiff base in the main chain were synthesized by using N, N′-bis(salicylidene)-1,3-propanediamine as a chain extender. Novel Schiff base PUs were synthesized via a two-step polymerization starting from a Schiff base derivative diol chain extender with different molar ratios or by cross-linking with various natural raw materials. The sought after structures was confirmed by Fourier transform infrared spectra that showed the disappearance of the signals of both the hydroxyl and isocyanate groups. The thermal properties of these PUs were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The initial degradation temperatures of the obtained PUs were found to be in the range of 300–350°C. Based on the results from DMA, the rigid structure of the Schiff base from the backbone of the PUs presented a higher storage modulus, results which may be connected to the physical cross-linking process of the macromolecules. Their optical properties were determined by fluorescence spectroscopy. The incorporation of Schiff base structures into the main PU chain generates new PU structures with improved thermomechanical properties, which includes possible bioactive Schiff base moieties, widening the range of practical applications for such polymers.

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In the current context, when studies regarding the planet's ability to sustain the human species consumption present more and more grim scenarios, it is required, more than ever, to consider sustainable development as a main priority for development strategies worldwide. In this sense, reducing the negative environmental impact of building materials and lowering energy consumption in buildings exploitation becomes the main axis for most of the new tendencies in architecture and civil engineering. Therefore, the development of new materials has to consider both low thermal conductivities and reduced embedded energy. The paper proposes a new mortar recipe based on expanded perlite and it presents an extensive study on the structural, physical and mechanical characteristics that the proposed material can provide, in order to reduce the negative environmental impact of buildings, by reducing buildings energy consumption, through increasing thermal resistance of the envelope. Finally, a series of conclusions and recommendations are presented on the way the proposed material can be used for the buildings thermal insulation process, both for new and refurbished buildings.

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