Polyurethane Hybrid Composites Reinforced with Lavender Residue Functionalized with Kaolinite and Hydroxyapatite

Abstract

Polyurethane (PUR) composites were modified with 2 wt.% of lavender fillers functionalized with kaolinite (K) and hydroxyapatite (HA). The impact of lavender fillers on selected properties of PUR composites, such as rheological properties (dynamic viscosity, foaming behavior), mechanical properties (compressive strength, flexural strength, impact strength), insulation properties (thermal conductivity), thermal characteristic (temperature of thermal decomposition stages), flame retardancy (e.g., ignition time, limiting oxygen index, heat peak release) and performance properties (water uptake, contact angle) was investigated. Among all modified types of PUR composites, the greatest improvement was observed for PUR composites filled with lavender fillers functionalized with kaolinite and hydroxyapatite. For example, on the addition of functionalized lavender fillers, the compressive strength was enhanced by ~16–18%, flexural strength by ~9–12%, and impact strength by ~7%. Due to the functionalization of lavender filler with thermally stable flame retardant compounds, such modified PUR composites were characterized by higher temperatures of thermal decomposition. Most importantly, PUR composites filled with flame retardant compounds exhibited improved flame resistance characteristics—in both cases, the value of peak heat release was reduced by ~50%, while the value of total smoke release was reduced by ~30%.

Polyurethane Composite Foams Synthesized Using Bio-Polyols and Cellulose Filler

“…RPURFs with higher values of the apparent density are characterized by a higher cross-linking density of the material as well as by a higher stiffness. The material becomes more resistant to external forces [50]. The modification of the PUR systems with cellulose did not improve the compressive strength, but the values for the direction parallel to the direction of foam growth exceed 200 kPa.…”

Polyurethane Composites Reinforced with Walnut Shell Filler Treated with Perlite, Montmorillonite and Halloysite

“…The polyaddition reaction leading to the production of polyurethane materials is carried out in the presence of chain extenders, catalysts, flame retardants, and blowing agents [ 5 ]. Due to the wide range of selection and modification of used raw materials, polyurethane products can be obtained in various forms, including foams, coatings, sealants, adhesives, films, and fibers [ 6 , 7 , 8 ].…”

“…Fillers of natural and plant origin may also positively affect the mechanical properties of the obtained composites. The literature commonly describes the use of natural additives in polymeric materials [ 8 , 9 , 15 , 16 , 17 , 18 , 19 , 20 ].…”

Biocomposites of Epoxidized Natural Rubber/Poly(Lactic Acid) Modified with Natural Substances: Influence of Biomolecules on the Aging Properties (Part II)

“…Hybrid plastic materials are being created for many reasons. Yet, some major factors might be highlighted: rising environmental awareness, trial of incorporation of less noxious nature-derived substances into the polymer technology and economic reasons (the need to balance the costs of biodegradable polymeric matrices by manufacturers) [ 7 , 8 , 9 , 10 , 11 , 12 , 13 ].…”