摘要
Abstract
To enhance the mechanical properties,thermal safety,and durable serviceability of thermoplastic polyurethane(TPU)in the construction field,TPU/CNS reinforced composites with different carbon nanosheet(CNS)mass fractions(0～2.0%)were prepared using a melt-blending and injection molding process.The effects of CNS content on the mechanical properties,thermal stability,flame retardancy,combustion behavior,and aging resistance of the composites were systematically investigated.The results showed that as the CNS content increased,the tensile strength and elastic modulus of the composites were significantly improved.When the CNS mass fraction was 1.5%,the tensile strength increased from 32.6 MPa to 41.1 MPa,with an increase of approximately 26%,and the notched impact strength reached 61.8 kJ/m2,demonstrating an optimal balance of strength and toughness.Thermogravimetric analysis revealed that the incorporation of CNS effectively enhanced the thermal stability of the material.The onset decomposition temperature of the composite containing 1.5%CNS rised to approximately 332℃,and its char yield at 600℃increased to 7.4%.Flame-retardant tests showed that CNS markedly improved both fire resistance and smoke suppression.The limiting oxygen index(LOI)rised from 22.3%to 26.1%,and the UL-94 rating reached V-0.Cone-calorimetry further indicated that the peak heat-release rate and total heat release dropped to 742 kW/m2 and 63.9 MJ/m2,respectively,while the smoke production rate and total smoke release were significantly reduced.Under accelerated UV/humidity aging,TPU/CNS reinforced composites exhibit higher retention of mechanical properties and less surface deterioration.Notably,the composite with 1.5%CNS still retained 90.5%of its original tensile strength after 28 days of aging.关键词
热塑性聚氨酯/碳纳米片/增强复合材料/阻燃性能/耐老化性能Key words
Thermoplastic polyurethane/Carbon nanosheets/Reinforced composites/Flame retardancy/Aging resistance分类
通用工业技术
