Zhang Yujie, Wang Changjian, Liang Jun, Wang Mengmeng, Fu Yingjuan, Zhang Yongchao, Tian Guoyu, Wang Zhaojiang
State Key Laboratory of Biobased Material and Green Papermaking, Qilu University of Technology (Shandong Academy of Sciences), Jinan 250353, China.
MCC Yinhe Paper Co., Ltd., Liaocheng 252000, China.
Int J Biol Macromol. 2025 Jan;284(Pt 1):137612. doi: 10.1016/j.ijbiomac.2024.137612. Epub 2024 Nov 20.
This study explored the synthesis of lignin-polyol (LP) by liquefaction of Kraft lignin in polyethylene glycol and glycerol. LP23 (23 wt% lignin) and LP41 (41 wt% lignin) were obtained with remarkable liquefaction yields of 97.43 % and 93.75 %, respectively. LP-based polyurethane film (LP-PUF) was then fabricated by reacting LP23 and LP41 with hexamethylene diisocyanate. Mechanical properties and hydrophobicity of LP-PUF were optimized by varying NCO/OH molar ratios. LP23-PUF1.9 with NCO/OH of 1.9 showed excellent tensile strength of 34.28 MPa and Young's modulus of 233.27 MPa, while LP41-PUF2.0 with NCO/OH of 2.0 exhibited good tensile strength of 26.03 MPa and Young's modulus of 260.66 MPa. LP23-PUF2.0 displayed high hydrophobicity as indicated by the water contact angle of 96.8° and low surface free energy of 15.68 mN/m. Glass transition temperature (Tg) of LP-PUF varied depending on lignin content and NCO/OH molar ratio. Specifically, the increase of KL content from 23 % to 42 % induced big rise of Tg by 8 °C. The NCO/OH induced change of Tg was relatively weak, as indicated by the small increase of -2.71 °C of LP41-PU1.4 to -1.81 °C of LP41-PUF2.0. The results of this work offer insights for lignin utilization as structural component of high modulus and high strength polyurethane film.
本研究探索了通过硫酸盐木质素在聚乙二醇和甘油中液化来合成木质素多元醇（LP）。获得了LP23（23 wt%木质素）和LP41（41 wt%木质素），其液化产率分别高达97.43%和93.75%。然后通过使LP23和LP41与六亚甲基二异氰酸酯反应制备了基于LP的聚氨酯薄膜（LP-PUF）。通过改变NCO/OH摩尔比优化了LP-PUF的机械性能和疏水性。NCO/OH为1.9的LP23-PUF1.9表现出优异的拉伸强度34.28 MPa和杨氏模量233.27 MPa，而NCO/OH为2.0的LP41-PUF2.0表现出良好的拉伸强度26.03 MPa和杨氏模量260.66 MPa。LP23-PUF2.0表现出高疏水性，水接触角为96.8°，表面自由能低至15.68 mN/m。LP-PUF的玻璃化转变温度（Tg）取决于木质素含量和NCO/OH摩尔比。具体而言，KL含量从23%增加到42%导致Tg大幅升高8°C。NCO/OH对Tg的影响相对较弱，如LP41-PU1.4的Tg从-2.71°C小幅增加到LP41-PUF2.0的-1.81°C所示。本工作的结果为木质素作为高模量和高强度聚氨酯薄膜的结构成分的利用提供了见解。
