亚麻油/混合蜡乳液构建木材内双层疏水体系  

Double Layer Wood Hydrophobic System Construction Via Linseed Oil/Mixed Waxes Hybrid Emulsions

作　　者：陈悰 王望[1] 曹金珍[1] Chen Cong;Wang Wang;Cao Jinzhen(College of Material Science and Technology, Beijing Forestry University ,Beijing 100083)

机构地区：[1]北京林业大学材料科学与技术学院,北京100083

出　　处：《林业科学》2021年第4期124-132,共9页Scientia Silvae Sinicae

基　　金：国家自然科学基金青年基金项目“基于复合乳液相分离的木材内蒙脱土杂化植物油/蜡双层疏水屏障的形成机制与调控”(31600452)。

摘　　要：【目的】利用环保、价廉的混合蜡和亚麻油乳液在木材内外表面构建双层疏水屏障,使其同时具备粗糙结构和连续防水层,进而兼具疏水和防水效果。【方法】配制亚麻油乳液、亚麻油/棕榈蜡乳液、亚麻油/混合蜡(蜂蜡/棕榈蜡、石蜡/棕榈蜡)乳液,对乳液性能进行评价。采用两步法和一步法浸渍杨木试件,通过70℃(两步法)和90~103℃(一步法)后处理温度在木材内外表面构建双层疏水屏障,并对处理材的表面疏水性、吸水性和尺寸稳定性进行测试。【结果】1)亚麻油乳液的平均粒径为195.6 nm,在室温下贮存稳定性良好,60天内粒径变化率仅为2.45%;亚麻油乳液与混合蜡乳液复合后的离心稳定性良好;2)亚麻油乳液在木材横向和纵向输水通道内均有分布,干燥后可在木材内表面形成连续油膜,并与混合蜡乳液构成双层疏水屏障;3)亚麻油/蜡改性方法能够有效提高木材的表面疏水性,两步法和一步法处理材横切面的接触角均在150°左右,且不随时间变化;而一步法处理材弦切面的疏水性好于两步法;4)亚麻油/蜡乳液复合改性材的吸水率降低,一步法的防水效率明显优于两步法,经过196 h泡水后,LB1和LP1处理材的防水效率保持在45%以上;复合改性方法亦能显著降低处理材前期的体积膨胀率,但最终影响差别不大。【结论】利用亚麻油/混合蜡乳液浸渍木材,仅通过后期干燥温度控制即可在木材内外表面形成兼具粗糙结构和连续防水层的双层疏水体系,赋予处理材优良的疏水性和防水性,是一种环保、节能、价廉的木材疏水改性方法。【Objective】The aim of current study is to improve the hydrophobicity and water repellency of wood by constructing double layer hydrophobic system in wood internal and external surfaces comprising a continuous linseed oil film with rough wax structure.【Method】Linseed oil,mixed wax and oil/wax hybrid emulsions were prepared and their properties were tested.The two-and one-step impregnation process was used to modify cathay poplar(Populus cathayana),followed by the heat treatment at 70℃(two-step process)or 90-103℃(one-step process)to form double layer hydrophobic barrier.The internal morphology of samples was characterized by field emission scanning electron microscopy(FE-SEM),and the weight percent gain,surface hydrophobicity,water absorption and volume swelling rate of treated samples were measured.【Result】1)The average particle size of linseed oil emulsion was about 195.6 nm,and its change rate under 60 days room-temperature storage was only 2.45%.The wax/oil hybrid emulsions also presented great stabilities after centrifugation test.2)FE-SEM images showed that both two-and one-step treatment processes could produce oil-wax double layer hydrophobic system with water repellent film and rough structures.3)The initial contact angle of treated wood on cross sections was nearly 150°and kept a good stability within 80 s detection,the one-step process treated wood presented a better performance than that of the two-step on the tangential section.4)The hybrid emulsions could further improve water repellency,and the water repellency efficiency(WRE)was above 35%and 45%with two-and one-step treatment,respectively.Clearly,one-step method performed better properties and simpler process.【Conclusion】Linseed oil/mixed waxes hybrid emulsions could improve the hydrophobicity and water repellency of poplar at the same time,it may be an eco-friendly,energy-saving and low cost method for wood hydrophobic modification.

关 键 词：木材 蜡 亚麻油 乳液 疏水性 

分 类 号：S781.7[农业科学—木材科学与技术]