Currently, polyurethane foam producers come across the several problems when petroleum-based polyols are replaced with low functionality biomass, or waste-based, polyols. In addition, the dilemma is intensified with regulations that require full or partial replacement of blowing agents that can cause high ozone depletion with alternatives like water, which causes the formation of CO₂. Therefore, these gases diffuse out of the foam so quickly that the polymeric cell walls cannot withstand the pressure, consequently causing huge dimensional changes at ambient temperature and humidity. Even though the theoretical stoichiometric balance is correct, the reality shows that it is not enough. Therefore, polyethylene terephthalate waste-based polyol was chosen as a low functionality polyol which was modified with high functionality sucrose-based polyol in order to obtain dimensionally stable polyurethane foams in the density range of 30–40 kg/m³. These more stable foams are characterized by linear changes no higher than 0.5%, short-term water absorption by partial immersion no higher than 0.35 kg/m², and water vapor resistance factors up to 50. In order to obtain thermally efficient polyurethane foams, conventional blowing agents and water systems were implemented, thus, assuring thermal conductivity values in the range of 0.0198–0.0204 W/(m·K) and obtaining products which conform to all the requirements for performance of sprayed and factory-made polyurethane foam standards EN 14315-1 and EN 13165.

Bio-sourced materials combined with a polymer matrix offer an interesting alternative to traditional building materials. To contribute to their wider acceptance and application, an investigation into the use of wood-polymer composite boards is presented. In this study, biocomposite boards (BcB) for the building industry are reported. BcB are fabricated using a dry incorporation method of corn starch (CS) and hemp shiv (HS) treatment with water at 100 °C. The amount of CS and the size of the HS fraction are evaluated by means of compressive bending and tensile strength, as well as microstructure. The results show that the rational amount of CS independently of HS fraction is 10 wt.%. The obtained BcB have compressive stress at 10% of deformation in the range of 2.4–3.0 MPa, bending of 4.4–6.3 MPa, and tensile strength of 0.23–0.45 MPa. Additionally, the microstructural analysis shows that 10 wt.% of CS forms a sufficient amount of contact zones that strengthen the final product.

The preparation of a glass-ceramic (GC)–polymethyl methacrylate (PMMA) composite material is reported. Precursor GC powders were synthesised via sol–gel method at 600 °C. XRD analysis revealed the formation of sodium calcium silicate (Na₆Ca₃Si₆O₁₈) as a main constituent phase of GC powders. The cylindrical-shaped GC–PMMA composite samples with fractional GC content ranging from 75 to 95% were prepared via photopolymerization reaction. The largest compressive strength for the composites containing 90% of GC has been determined. The growth of ceramic layer on the surface of composites immersed into simulated body fluid (SBF) under static conditions was studied by ICP-OES, FE-SEM/EDX, FTIR and XRD techniques. The changes in the concentrations of Ca, Si and P after the dissolution indicate the degradation process of GC–PMMA composites. The structures of the resultant surface confirmed the formation of new ceramic layer on the surface of composite materials. FTIR and XRD analyses revealed the deposition of low-crystallinity calcium phosphate layer with the composition similar to that of the carbonated hydroxyapatite (cHAP) after the soaking in SBF.