目的 将经过3-甲基丙烯酰氧基丙基三甲氧基硅烷(MPS)改性的纳米结晶纤维素(NCC)添加到水性聚氨酯(WPU)基材中制备复合连接料，以明确改性NCC对复合连接料抗热老化性能的改善效果。方法 通过扫描电镜(SEM)和红外光谱(FT-IR)对复合连接料的外观形貌及化学结构进行表征，并测定经不同老化条件处理后复合连接料的热致质量损失、镜面光泽度和剥离强度。结果 与经过同等条件老化处理的原始连接料相比，改性NCC质量分数为2.0%的复合连接料在140 ℃下老化处理96 h后，质量损失率降低了5.9%，镜面光泽度和剥离强度分别下降了51.1%和44.7%，明显低于原始连接料在同等条件下的下降幅度。结论 改性NCC的添加可显著改善连接料的热致质量损失现象，并能够有效降低高温处理对涂层镜面光泽度和剥离强度的破坏。

The work aims to specify the effect of modified nanocrystalline cellulose (NCC) on improving the thermal aging resistance of composite binder, with NCC modified by 3-glycidoxypropyltrimethoxysilane (MPS) and then added to waterborne polyurethane (WPU) for the preparation of the composite binder. The appearance morphology and chemical structure of composite binder were characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectrophotometer (FT-IR). The thermally induced weight loss, specular gloss and peel strength of composite binder after processing under different aging conditions were determined. Compared to the original binder subject to aging treatment under the same conditions, when the composite binder containing 2.0% modified NCC was subject to aging treatment at 140 ℃ for 96 h, its weight loss rate was reduced by 5.9%. After a 96 h aging treatment at 140 ℃, the specular gloss and peel strength of the composite binder containing 2.0% modified NCC were respectively reduced by 51.1% and 44.7%, which were obviously less than those of the original binder under the same conditions. The addition of modified NCC can significantly improve the thermally induced weight loss of the binder and effectively reduce the damages of high-temperature treatment caused to coating specular gloss and peel strength.