聚氨酯/咖啡渣泡沫的发泡行为和慢回弹性能研究

Study on Foaming Behavior and Slow Resilience Performance of Polyurethane/Coffee Ground Foams

利用废弃生物质咖啡渣(CFG)填充反应改性制备具有慢回弹特性的聚氨酯泡沫,对其发泡行为,泡沫的回弹特性、力学性能和隔热性能进行研究。结果表明,CFG参与聚氨酯聚合的链增长反应,同时减少二苯基甲烷二异氰酸酯(MDI)与水反应产生的发泡气体量。此外,CFG含量对泡孔结构和泡沫性能具有影响作用。在40%(质量分数,下同)的CFG填加量时,聚氨酯泡沫的开孔率从57%降低至15%;其拉伸强度和模量分别提高至0.15 MPa和33.5 MPa,热导率降低至0.050 W/(m·K);在37℃下,其回弹时间大于3 s,具有良好的慢回弹特性;CFG填充改性具有对慢回弹聚氨酯泡沫泡孔结构和性能的调控效应。

The slow resilient PU foams with high loadings of coffee grounds were prepared by a reactive blending method, and their slow resilience performance, mechanical properties, thermal insulation and foaming behaviors were investigated. The results indicated that the hydroxyl groups on coffee grounds could react with isocyanate groups of MDI, but the foaming reaction was inhibited, resulting in a decrease in the amount of foaming gas. In addition, the cellular structure and foaming properties of the PU foams were greatly influenced by the addition of coffee grounds. With the content of coffee grounds as high as 40 wt%, the open cell ratio of the PU foams decreased from 57% to 15%, whereas their tensile strength and moduli were improved to 0.15 MPa and 33.5 MPa, respectively. Moreover, the thermal conductivity of the PU foams decreased to 0.050 W/(m·K), and their resilience time exceeded 3 s at 37℃. The addition of coffee grounds could generate a positive effect on the cellular structure and performance control of low-resilient PU foams.