Institute of Polymer & Dye Technology, Lodz University of Technology, 90-924 Lodz, Poland.
Laboratory of Thermal Insulating Materials and Acoustics, Faculty of Civil Engineering, Institute of Building Materials, Vilnius Gediminas Technical University, Linkmenu St. 28, LT-08217 Vilnius, Lithuania.
Int J Mol Sci. 2021 Jul 7;22(14):7304. doi: 10.3390/ijms22147304.
In the following study, polyurethane (PUR) composites were modified with 2 wt.% of walnut shell filler modified with selected mineral compounds-perlite, montmorillonite, and halloysite. The impact of modified walnut shell fillers on selected properties of PUR composites, such as rheological properties (dynamic viscosity, foaming behavior), mechanical properties (compressive strength, flexural strength, impact strength), dynamic-mechanical behavior (glass transition temperature, storage modulus), insulation properties (thermal conductivity), thermal characteristic (temperature of thermal decomposition stages), and flame retardant properties (e.g., ignition time, limiting oxygen index, heat peak release) was investigated. Among all modified types of PUR composites, the greatest improvement was observed for PUR composites filled with walnut shell filler functionalized with halloysite. For example, on the addition of such modified walnut shell filler, the compressive strength was enhanced by ~13%, flexural strength by ~12%, and impact strength by ~14%. Due to the functionalization of walnut shell 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 all cases, the value of peak heat release was reduced by ~12%, while the value of total smoke release was reduced by ~23%.
在以下研究中，用 2 重量%的经选定的矿物质化合物（珍珠岩、蒙脱石、和埃洛石）改性的核桃壳填料对聚氨酯（PUR）复合材料进行了改性。改性核桃壳填料对 PUR 复合材料的某些性能的影响，如流变性能（动态粘度、发泡行为）、力学性能（抗压强度、弯曲强度、冲击强度）、动态力学性能（玻璃化转变温度、储能模量）、隔热性能（导热系数）、热特性（热分解阶段温度）和阻燃性能（如点燃时间、氧指数、热峰值释放）进行了研究。在所有改性类型的 PUR 复合材料中，用埃洛石功能化的核桃壳填料填充的 PUR 复合材料的改进最大。例如，在添加这种改性核桃壳填料的情况下，抗压强度提高了约 13%，弯曲强度提高了约 12%，冲击强度提高了约 14%。由于核桃壳填料用热稳定的阻燃化合物进行了功能化，因此改性 PUR 复合材料的热分解温度更高。最重要的是，填充有阻燃化合物的 PUR 复合材料表现出了更好的阻燃特性——在所有情况下，峰值热释放值降低了约 12%，而总烟雾释放值降低了约 23%。
