Characterization and application of a natural polymer obtained from Hydrangea macrophylla as a thermal insulation biomaterial

Thermal insulation materials play a significant role in improving the energy efficiency of buildings and therefore many studies focus their efforts on developing low environmental impact materials. In this context, the aim of this work was to study a natural polymer obtained from Hydrangea Macrophylla (HM) and its application as a thermal insulation material. The natural polymer was chemically, physically and mechanically characterized and compared to polyurethane (PU) and expanded polystyrene (EPS). In addition, a composite material blended in a mold using HM stems and sprayed with PU was used to evaluate possible applications. The results obtained from morphological studies conducted on HM showed it to be an interesting natural porous structure with a smooth surface similar to those found in closed cell insulation materials and highly compatible with PU foam. This composite showed good thermal stability, an outstanding thermal conductivity for a natural insulation material, high density and good behavior under compression. HM polymer in a PU matrix like a block type was shown to be an appropriate thermal insulation material, providing an excellent opportunity to reduce the environmental impacts of these types of insulating foams.