Elaboration of Thermally Performing Polyurethane Foams, Based on Biopolyols, with Thermal Insulating Applications

Abstract

In this work, biobased rigid polyurethane foams (PUFs) were developed with the aim of achieving thermal and fireproofing properties that can compete with those of the commercially available products. First, the synthesis of a biopolyol from a wood residue by means of a scaled-up process with suitable yield and reaction conditions was carried out. This biopolyol was able to substitute completely the synthetic polyols that are typically employed within a polyurethane formulation. Different formulations were developed to assess the effect of two flame retardants, namely, polyhedral oligomeric silsesquioxane (POSS) and amino polyphosphate (APP), in terms of their thermal properties and degradation and their fireproofing mechanism. The structure and the thermal degradation of the different formulations was evaluated via Fourier Transformed Infrared Spectroscopy (FTIR) and thermogravimetric analysis (TGA). Likewise, the performance of the different PUF formulations was studied and compared to that of an industrial PUF. From these results, it can be highlighted that the addition of the flame retardants into the formulation showed an improvement in the results of the UL-94 vertical burning test and the LOI. Moreover, the fireproofing performance of the biobased formulations was comparable to that of the industrial one. In addition to that, it can be remarked that the biobased formulations displayed an excellent performance as thermal insulators (0.02371–0.02149 W·m−1·K−1), which was even slightly higher than that of the industrial one.

Conjugated Microporous Polymer Aerogels Encapsulated within Hydroxyapatite Nanowires Exhibit Good Thermal Insulation and Flame-Retardant Properties

“…To test the thermal insulation performance of the aerogel, its thermal conductivity is shown in Figure a; the thermal conductivity of the pure sample NCMP is 0.0251 W m –1 K –1 , and the thermal conductivity of the aerogel with the addition of hydroxyapatite did not have a significant change compared to the thermal conductivity of NCMP and still maintains a low level. In addition, as show in Figure S2, compared with the existing thermal insulation materials, ,− HAP-NMCPs still show a low thermal conductivity. Further, we used an infrared camera to record the temperature profile of the aerogel on the hot platform at 65 °C within 30 min, as shown in Figure a, b.…”