Anter Nadia, Chennani Ahlam, Guida Mohamed-Yassine, Atmani Fatima Ezzahra, Moubarik Amine, Rakib El Mostapha, Medaghri-Alaoui Abdelouahid, Hannioui Abdellah
Molecular Chemistry, Materials and Catalysis Laboratory, Faculty of Sciences and Techniques (FST-BM), University of Sultan Moulay Slimane (USMS) Béni-Mellal 23000 Morocco
Environmental, Ecological and Agro-Industrial Engineering Laboratory, Faculty of Sciences and Techniques (FST-BM), University of Sultan Moulay Slimane (USMS) Béni-Mellal 23000 Morocco.
RSC Adv. 2025 Sep 5;15(39):32118-32130. doi: 10.1039/d5ra04233j.
Biopolymers derived from natural sources are sustainable, non-toxic, and biodegradable, making them attractive alternatives to fossil-based polymers. Among these, lignin has garnered significant attention due to its potential in adhesive applications. In this study, lignin was extracted from redwood ( L.) sawdust using an alkaline delignification process and subsequently modified through propargylation and silanization. Comprehensive characterization using FTIR, solubility tests, TGA/DTG, H NMR, SEM-EDX, and contact angle measurements confirmed significant improvements in physicochemical properties. Notably, silylated lignins exhibited enhanced solubility in low-polarity solvents and a marked increase in hydrophobicity, with water contact angles reaching 127.7°. Phenol-formaldehyde (PF) adhesives incorporating raw and modified lignins (5-15 wt%) were formulated and applied in plywood production. Mechanical testing revealed that plywood bonded with 10 wt% Prop-lignin-DH achieved a bond strength of 5.44 MPa and 100% wood failure, outperforming conventional lignin-based adhesives. Furthermore, compared to the control PF resin, the modulus of rupture (MOR) and modulus of elasticity (MOE) increased by 38% and 27.3%, respectively. Shear strength also improved significantly, with gains of 56.1% under dry conditions, 17.6% in cold water, and 74.1% after boiling. In addition, formaldehyde emissions were reduced by 20% compared to standard PF resins, highlighting the potential of silylated lignin as a sustainable adhesive modifier for wood-based composites.
源自天然来源的生物聚合物具有可持续性、无毒且可生物降解，使其成为基于化石的聚合物的有吸引力的替代品。其中，木质素因其在胶粘剂应用中的潜力而备受关注。在本研究中，采用碱性脱木质素工艺从红木锯末中提取木质素，随后通过炔丙基化和硅烷化进行改性。使用傅里叶变换红外光谱（FTIR）、溶解度测试、热重分析/微商热重分析（TGA/DTG）、核磁共振氢谱（¹H NMR）、扫描电子显微镜-能谱分析（SEM-EDX）和接触角测量进行的全面表征证实了其物理化学性质有显著改善。值得注意的是，硅烷化木质素在低极性溶剂中的溶解度增强，疏水性显著增加，水接触角达到127.7°。配制了含有未改性和改性木质素（5-15 wt%）的酚醛（PF）胶粘剂，并应用于胶合板生产。力学测试表明，用10 wt%的炔丙基化木质素-DH粘结的胶合板的粘结强度达到5.44 MPa，木材破坏率为100%，优于传统的木质素基胶粘剂。此外，与对照PF树脂相比，断裂模量（MOR）和弹性模量（MOE）分别提高了38%和27.3%。剪切强度也显著提高，在干燥条件下提高了56.1%，在冷水中提高了17.6%，在煮沸后提高了74.1%。此外，与标准PF树脂相比，甲醛排放量减少了20%，突出了硅烷化木质素作为木质基复合材料可持续胶粘剂改性剂的潜力。
