Guo Wenwen, Chen Shun, Liang Fuwei, Jin Liping, Ji Chenpeng, Zhang Ping, Fei Bin
Key Laboratory of Eco-textiles, Ministry of Education, College of Textile Science and Engineering, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China; State Key Laboratory of Environment-friendly Energy Materials, Southwest University of Science and Technology, Mianyang 621010, China; Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China; State Key Laboratory of Fire Science, University of Science and Technology of China, 96 Jinzhai Road, Hefei, Anhui 230026, China.
Key Laboratory of Eco-textiles, Ministry of Education, College of Textile Science and Engineering, Jiangnan University, 1800 Lihu Avenue, Wuxi, Jiangsu 214122, China.
Int J Biol Macromol. 2023 Aug 15;246:125343. doi: 10.1016/j.ijbiomac.2023.125343. Epub 2023 Jun 16.
Cellulosic aerogels (CNF) are considered naturally available thermal insulating materials as substitutes for conventional polymeric aerogels owing to their extensive sources, low density, low thermal conductivity, sustainability and biodegradability. However, cellulosic aerogels suffer from high flammability and hygroscopicity. In this work, a novel P/N-containing flame retardant (TPMPAT) was synthesized to modify cellulosic aerogels to improve their anti-flammability. TPMPAT/CNF aerogels were further modified by polydimethylsiloxane (PDMS) to enhance the water-proof characteristics. Although the addition of TPMPAT and/or PDMS slightly increased the density and thermal conductivity of the composite aerogels, those values were still comparable to the commercial polymeric aerogels. Compared with pure CNF aerogel, the cellulose aerogel modified by TPMPAT and/or PDMS had higher T, T and T, which indicated that the modified cellulose aerogels have better thermal stability. TPMPAT modification made CNF aerogels highly hydrophilic, while TPMPAT/CNF aerogel modified by PDMS became a highly hydrophobic material with a water contact angle (WCA) of 142°. Pure CNF aerogel burned rapidly after ignition, showing a low limiting oxygen index (LOI) of 23.0% and no UL-94 grade. In contrast, both TPMPAT/CNF-30% and PDMS-TPMPAT/CNF-30% showed self-extinction behaviors with a UL-94 V-0 grade, implying high fire resistance. Combined with high anti-flammability and hydrophobicity, the ultra-light-weight cellulosic aerogels show great potential for thermal insulation applications.
纤维素气凝胶（CNF）因其来源广泛、密度低、导热系数低、可持续性和生物降解性，被认为是可天然获取的隔热材料，可替代传统的聚合物气凝胶。然而，纤维素气凝胶具有高易燃性和吸湿性。在这项工作中，合成了一种新型含磷/氮阻燃剂（TPMPAT）来改性纤维素气凝胶，以提高其阻燃性。TPMPAT/CNF气凝胶进一步用聚二甲基硅氧烷（PDMS）改性，以增强防水性能。尽管添加TPMPAT和/或PDMS会略微增加复合气凝胶的密度和导热系数，但这些值仍与商业聚合物气凝胶相当。与纯CNF气凝胶相比，经TPMPAT和/或PDMS改性的纤维素气凝胶具有更高的T、T和T，这表明改性纤维素气凝胶具有更好的热稳定性。TPMPAT改性使CNF气凝胶具有高亲水性，而经PDMS改性的TPMPAT/CNF气凝胶成为具有142°水接触角（WCA）的高疏水性材料。纯CNF气凝胶点火后迅速燃烧，极限氧指数（LOI）低至23.0%，且无UL-94等级。相比之下，TPMPAT/CNF-30%和PDMS-TPMPAT/CNF-30%均表现出自熄行为，具有UL-94 V-0等级，意味着具有高耐火性。结合高阻燃性和疏水性，超轻质纤维素气凝胶在隔热应用中显示出巨大潜力。
