表面活性剂含量对石蜡乳液改性中密度纤维板表面润湿性的影响  

Effects of surfactant content on the surface wettability of medium density fiberboard modified by paraffin emulsion

作　　者：杨萌[1] 王望[1] 罗文圣 马尔妮[1] Yang Meng;Wang Wang;Luo Wensheng;Ma Erni(Beijing Key Laboratory of Wood Science and Engineering,Beijing Forestry University,Beijing 100083,China;Beijing Shengda Huayuan Technology Co.Ltd.,Beijing 100070,China)

机构地区：[1]北京林业大学材料科学与工程北京市重点实验室,北京100083 [2]北京盛大华源科技有限公司,北京100070

出　　处：《北京林业大学学报》2022年第8期117-124,共8页Journal of Beijing Forestry University

基　　金：国家自然科学基金项目(31971583),“科技助力经济2020”重点专项“速生材制备功能型木质复合材料技术及应用”。

摘　　要：【目的】探究表面活性剂含量对石蜡乳液改性中密度纤维板表面润湿性的影响,为蜡基防水剂的开发及应用提供理论依据及技术参考。【方法】以58号石蜡、司盘80、吐温80为原料制备了表面活性剂质量分数分别为2%、4%、6%、8%的4组石蜡乳液,并用于对中密度纤维板试件进行常压浸渍处理。利用接触角测量仪评估中密度纤维板试件表面被水润湿和渗透的能力;通过场发射电子扫描显微镜(FESEM)、X射线光电子能谱(XPS)对试件表面的微观形貌和元素组成进行表征分析。【结果】与未处理材相比,处理材的初始接触角增大,且接触角和表面液滴体积下降速率明显减慢;对处理材而言,随着石蜡乳液中表面活性剂质量分数的增加,处理材的初始接触角减小,接触角和表面液滴体积下降速率加快。FESEM和XPS结果表明:增加石蜡乳液中表面活性剂的质量分数会导致试件表面更为平滑,同时使得处理材表面的C1/C2值减小。【结论】随着表面活性剂质量分数的增加,石蜡颗粒更容易在试件表面碰撞聚集,同时生成表面活性剂分子的双层结构,处理材的表面润湿性由于表面粗糙度的降低和亲水基团数量的增多而提高。降低表面活性剂质量分数有助于降低石蜡乳液改性中密度纤维板的表面润湿性,对蜡基防水剂的开发与应用具有重要的指导意义。[Objective]This paper aims to explore the effects of surfactant content on the surface wettability for medium density fiberboard(MDF)modified by paraffin emulsion,which can provide theoretical basis and technical supports for the development and application of paraffin-based waterproofing agent.[Method]Four groups of paraffin emulsions with different mass fractions of surfactant at 2%,4%,6% and 8% were prepared by 58#paraffin,Span 80 and Tween 80 as raw materials and the paraffin emulsions were used to treat the medium density fiberboard(MDF)samples by impregnation under normal pressure.Surface wettability of the samples was assessed by contact angle measurement;microstructure and elemental composition of the sample surfaces were characterized and analyzed by field emission scanning electron microscope(FESEM)and X-ray photoelectron spectroscopy(XPS).[Result]Compared with the untreated samples,the initial contact angle of the treated samples increased,and the declining rate of contact angle and surface droplet volume decreased significantly.With an increase in the mass fraction of surfactant,the initial contact angle of the treated samples decreased,and the decreasing rate of contact angle and surface droplet volume accelerated.FESEM and XPS results showed that increasing mass fraction of surfactant in paraffin emulsion would lead to a smoother sample surface and reduce the C1/C2 value on the treated sample surfaces.[Conclusion]With an increase in mass fraction of surfactant,paraffin wax particles tend to collide and aggregate and a double layer structure of surfactant molecules is formed on the sample surfaces.The surface wettability of the treated samples is improved due to the reduction in surface roughness as well as the increased amount of hydrophilic groups.Lowering the mass fraction of surfactant could reduce the surface wettability of MDF modified by paraffin emulsion,which provide an insight into the development and application of paraffin-based waterproofing agent.

关 键 词：表面活性剂含量 石蜡乳液 表面润湿性 中密度纤维板(MDF) 

分 类 号：S781.43[农业科学—木材科学与技术]