纤维素/聚氨酯复合气凝胶的制备

以LiOH/尿素（urea） /H2O溶液体系制备的再生纤维素为凝胶骨架,HDI三聚体（N3300）为单体,二月桂酸二丁基锡（DBTDL）为催化剂,原位生成了纤维素/聚氨酯（PU）复合凝胶,再冷冻干燥得到纤维素/PU复合气凝胶.通过红外光谱分析（FT-IR）、X射线衍射（XRD）、扫描电子显微镜（SEM）、N2吸附-脱附、压缩试验对其结构和性能表征.结果表明：纤维素和N3300反应,改变了纤维素的物理和化学结构;N3300浓度增加,与纤维素骨架反应程度增加,复合气凝胶的力学性能增加,SBET和孔隙率减小,密度增加;N3300用量适宜时,可实现复合气凝胶综合性能的平衡.

Study on the Preparation of Cellulose/PU Aerogel Composites

The cellulose/PU aerogel composites were prepared in situ using regenerated cellulose prepared by LiOH/urea/H2O solution as gel skeleton, HDI trimer （N3300） as the monomer, dibutyltindilaurate （DBTDL） as the catalyst, and finally obtained cellulose/PU composited aerogel by freeze-drying. The structure and the performance of aerogels were characterized by FTIR, XRD, SEM, N2 adsorption-desorption and compression test. The results showed that cellulose and N3300 reacted, which changed physical and chemical structures of cellulose With the increasing concentration of N3300, the in situ reaction degree of tri-isocyanate on three-dimensional skeletal structure of cellulose became higher, mechanical properties of aerogel composites increased, while SBET and porosity decreased, density increased. When N3300 dosage was appropriate, balanced overall performance of aerogel composites could be achieved.