机构地区:[1]安徽省高性能生物基尼龙工程研究中心,安徽农业大学材料与化学学院,安徽合肥230036
出 处:《木材科学与技术》2025年第1期37-46,共10页Chinese Journal of Wood Science and Technology
基 金:国家自然科学基金青年项目“基于仿生“类多巴”分子拓扑结构构建的桐油基压敏胶黏附增强机制研究”(32401532);“十四五”国家重点研发计划项目“木本油脂基高抗材料制备关键技术”(2022YFD2200802)。
摘 要:表面涂饰是提升木制品附加值和使用性能的重要手段,研究开发具有自修复功能的绿色水性木器涂料是实现木材保护和提质增值的有效途径。以桐油为原料,通过油脂分子功能化可控合成及定向调控制备木器用生物基水性聚氨酯涂料,实现木质材料表面涂层的强化、高黏附界面和自修复功能集成。利用桐油脂肪酸长碳链段的疏水效应,有效降低聚氨酯体系中分子水敏感性,改善涂层耐湿黏附性能;侧链共轭双键的氧化交联特性可赋予涂层良好的自固化效能;采用硼酸酯键封端为聚氨酯网络结构提供动态响应单元,实现水性涂层在室温环境下高效自修复。通过系统研究涂层及其与木材间的界面特性,包括本体力学强度、界面黏附、耐磨性等,阐明涂层与木器表面之间相互作用的微观机制,结果表明:制备的桐油基水性聚氨酯乳液具有稳定且均一的分散特性,其Zeta电位绝对值均在30 mV以上;当引入纳米纤维素添加量为1.0%(质量分数)时,有效提升复合涂层的力学性能(拉伸强度9.3 MPa、杨氏模量11.3 MPa、断裂能19.58 kJ/m2);室温修复效率可达98.4%(以断裂应变为参照);涂饰于木基材表面后表现良好的黏附及耐磨性能,在潮湿环境(RH 95%)下依然具有稳定的界面黏附强度(搭接剪切强度7.1 MPa)。Surface coating is an important method to increase the value and expand the application of wood products.The scientific research and product development on green waterborne wood coatings with self-repairing function is an effective way to achieve the protection of wood,enhance the quality,and increase the product values.Using tung oil as a raw material,bio-based waterborne polyurethane coatings are prepared through controlled synthesis and directional regulation of oil molecular functionalization to strengthen the surface coating of wood materials,heighten interfacial adhesion and increase integration of self-repair functions.The hydrophobic effect of the long carbon chain segment of tung oil fatty acids effectively reduces the molecular water sensitivity of the polyurethane system and improves the wet adhesion resistance of the coating;the oxidative cross-linking property of the conjugated double bonds of the side chains give the coating a good self-curing performance;and the use of boronated ester bond capping provides a dynamic response unit for the polyurethane network structure,which realizes the high efficiency of self-repairing of water-based coatings under the room temperature environment.The microscopic mechanism of the interaction between the coating and the wood surface is elucidated by systematically investigating the coating and its wood interfacial properties,including intrinsic mechanical strength,interfacial adhesion,and abrasion resistance.The results show that the prepared tung oil-based aqueous urethane emulsions have a stable and homogeneous dispersion characteristics;the absolute values of the zeta potentials are over 30 mV;when the nanocellulose additive content is introduced to 1.0%(mass fraction),the mechanical properties of the composite coatings(tensile strength,tensile strength,abrasion resistance,etc.)are effectively improved.When nanocellulose is introduced at 1.0%,the mechanical properties of the composite coating are improved(tensile strength of 9.3 MPa,modulus of 11.3 MPa,and fract
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