硅酸钠/聚乙二醇浸渍改性杨木工艺及性能研究

目的 为了提高速生杨木的物理力学性能、尺寸稳定性、热稳定性等性能,以硅酸钠(Na2SiO3)溶液和聚乙二醇(PEG)溶液为改性剂,旨在提高杨木的力学性能、尺寸稳定性以及耐热性能,并探究硅酸钠质量分数、聚乙二醇质量分数以及分子量对改性杨木性能的影响,获得最佳浸渍工艺。方法 运用单因素试验法探究硅酸钠质量分数、聚乙二醇质量分数、聚乙二醇分子量3个因素对改性杨木浸渍效果的影响。通过最佳浸渍工艺制备硅酸钠/聚乙二醇改性杨木与硅酸钠改性杨木,并测定其顺纹抗压强度、表面硬度、吸湿体积膨胀率等性能和结构表征,探究其与未改性杨木的差异。结果 通过单因素试验结果可知,以质量分数为10%的Na2SiO3、PEG-400以及质量分数为5%的PEG-400的浸渍工艺制备出改性杨木性能较佳。硅酸钠/聚乙二醇杨木改性材的顺纹抗压强度、抗弯强度、端面硬度、径面硬度和弦面硬度较未改性杨木的分别提高了69.4%、19.1%、42.2%、39.5%、19.2%,吸湿体积膨胀率较硅酸钠改性材降低了40.0%。结论 速生杨木经过硅酸钠/聚乙二醇改性后的力学强度,相较于单独硅酸钠改性杨木的力学强度有所提升,尺寸稳定性能增强,因此在性能及应用方面,硅酸钠/聚乙二醇改性杨木更具优势。

Technology and Properties of Sodium Silicate/Polyethylene Glycol Impregnation Modified Poplar Wood

The work aims to use sodium silicate (Na2SiO3) solution and polyethylene glycol (PEG) solution as modifiers to improve the mechanical properties, dimensional stability and thermal stability of fast-growing poplar wood and study the effect of sodium silicate concentration, polyethylene glycol concentration and molecular weight on the properties of modified poplar wood, and obtain the optimum impregnation process. The effect of sodium silicate concentration, polyethylene glycol concentration and polyethylene glycol molecular weight on the impregnation effect of modified poplar wood was investigated by single factor test. Sodium silicate/polyethylene glycol modified poplar wood and sodium silicate modified poplar wood were prepared by the optimum impregnation process, and their in-grain compressive strength, surface hardness, moisture absorption volume expansion rate and other properties and structural characteristics were measured to explore their differences with unmodified poplar wood. The results of single factor test showed that the modified poplar wood prepared with 10% Na2SiO3, PEG-400 and 5% PEG-400 had the best property. The grain compressive strength, bending strength, end hardness, diameter surface hardness and chord surface hardness of the modified wood were increased by 69.4%, 19.1%, 42.2%, 39.5% and 19.2%, respectively, and the hygroscopic volume expansion rate was decreased by 40.0% compared with the modified wood. After sodium silicate and polyethylene glycol modification, the mechanical strength and dimensional stability of fast-growing poplar wood are improved compared with sodium silicate modified poplar wood alone, so the sodium silicate/polyethylene glycol modified poplar wood has more advantages in property and application.