Yang Haocheng, Cao Suzhou, Cui Xinpeng, Xi Zhonghua, Cai Jun, Yuan Zuanru, Zhang Junsheng, Xie Hongfeng
MOE Key Laboratory of High Performance Polymer Materials and Technology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Experimental Chemistry Teaching Center, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Polymers (Basel). 2025 Jul 26;17(15):2045. doi: 10.3390/polym17152045.
Bio-based polyurethane asphalt binder (PUAB) derived from castor oil (CO) is environmentally friendly and exhibits extended allowable construction time. However, CO imparts inherently poor mechanical performance to bio-based PUAB. To address this limitation, attapulgite (ATT) with fibrous nanostructures was incorporated. The effects of ATT on bio-based PUAB were systematically investigated, including cure kinetics, rotational viscosity (RV) evolution, phase-separation microstructures, dynamic mechanical properties, thermal stability, and mechanical performance. Experimental characterization employed Fourier transform infrared spectroscopy, Brookfield viscometry, laser scanning confocal microscopy, dynamic mechanical analysis, thermogravimetry, and tensile testing. ATT incorporation accelerated the polyaddition reaction conversion between isocyanate groups in polyurethane (PU) and hydroxyl groups in ATT. Paradoxically, it reduced RV during curing, prolonging allowable construction time proportionally with clay content. Additionally, ATT's compatibilizing effect decreased bitumen particle size in PUAB, with scaling proportionally with clay loading. While enhancing thermal stability, ATT lowered the glass transition temperature and damping properties. Crucially, 1 wt% ATT increased tensile strength by 71% and toughness by 62%, while maintaining high elongation at break (>400%). The cost-effectiveness and significant reinforcement capability of ATT make it a promising candidate for producing high-performance bio-based PUAB composites.
源自蓖麻油（CO）的生物基聚氨酯沥青结合料（PUAB）具有环境友好性且施工允许时间延长。然而，蓖麻油使生物基PUAB的固有机械性能较差。为解决这一局限性，引入了具有纤维纳米结构的凹凸棒石（ATT）。系统研究了凹凸棒石对生物基PUAB的影响，包括固化动力学、旋转粘度（RV）演变、相分离微观结构、动态力学性能、热稳定性和机械性能。实验表征采用傅里叶变换红外光谱、布鲁克菲尔德粘度测定法、激光扫描共聚焦显微镜、动态力学分析、热重分析和拉伸试验。加入凹凸棒石加速了聚氨酯（PU）中异氰酸酯基团与凹凸棒石中羟基之间的加成聚合反应转化。矛盾的是，它在固化过程中降低了旋转粘度，允许施工时间与粘土含量成比例延长。此外，凹凸棒石的增容作用减小了PUAB中的沥青颗粒尺寸，与粘土负载量成比例缩放。在提高热稳定性的同时，凹凸棒石降低了玻璃化转变温度和阻尼性能。至关重要的是，1 wt%的凹凸棒石使拉伸强度提高了71%，韧性提高了62%，同时保持了较高的断裂伸长率（>400%）。凹凸棒石的成本效益和显著的增强能力使其成为生产高性能生物基PUAB复合材料的有前途的候选材料。
