Ageing of modified wood. Part 1: Wetting properties of acetylated, furfurylated, and thermally modified wood
Ageing of modified wood. Part 1: Wetting properties of acetylated, furfurylated, and thermally modified wood
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DOI：
10.1515/hf.2010.040
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发表时间：
2010-04-01
期刊：
影响因子：
2.4
通讯作者：
Walinder, Magnus E. P.
中科院分区：
文献类型：
--
作者：
Bryne, Lars Elof;Walinder, Magnus E. P.
本工作的主要目的是应用接触角分析来预测某些改性木材材料与某些热塑性塑料和胶粘剂之间的粘附功（W-a）。润湿性能，即，通过Wilhelmy方法在未改性和乙酰化的苏格兰松、糠化辐射松和热处理的挪威云杉的新鲜制备的和老化的单板样品上测量接触角。用座滴法测定了苯酚-间苯二酚-甲醛、乳液聚合物-异氰酸酯和单组分聚氨酯胶粘剂的接触角。接触角数据也收集自关于聚乙烯、聚氯乙烯、聚甲基丙烯酸甲酯、聚苯乙烯和尼龙6的文献。然后应用基于Chang-Qin-Chen模型的接触角分析来确定木材样品与所选择的热塑性塑料和粘合剂之间的所谓的酸碱相互作用参数和W-a。结果表明，老化过程导致增加的疏水特性的未改性，热处理，和糠化木材样品。新鲜制备的乙酰化木材样品具有明显的疏水特性，其在老化后保持大致恒定。木材与胶粘剂之间的预测W-a显著高于木材与热塑性塑料之间的预测W-a。此外，当比较新鲜样品和老化样品时，乙酰化木材与热塑性塑料和水之间的预测W-a大致不变。相反，所有其他木材样品的老化导致木材-水W-a的急剧下降和木材-热塑性塑料W-a的适度下降。然而，当比较新鲜和老化样品时，木材粘合剂W-a对于未改性和糠化木材是不变的，并且对于热处理和乙酰化木材样品甚至增加。
The main objective of this work was to apply contact angle analysis to predict work of adhesion (W-a) between some modified wood materials and certain thermoplastics and adhesives. Wetting properties, i.e., contact angles, were measured by the Wilhelmy method on both freshly prepared and aged veneer samples of unmodified and acetylated Scots pine, furfurylated radiata pine, and heat treated Norway spruce. The sessile drop method was used to measure contact angles on a phenol resorcinol formaldehyde, an emulsion polymer isocyanate, and a one-component polyurethane adhesive. Contact angle data were also collected from the literature on polyethylene, polyvinyl chloride, polymethyl methacrylate, polystyrene, and Nylon 6. Contact angle analysis based on the Chang-Qin-Chen model was then applied to determine so-called acid-base interaction parameters and W-a between the wood samples and the selected thermoplastics and adhesives. Results show that the ageing process led to an increased hydrophobic character of unmodified, heat treated, and furfurylated wood samples. The freshly prepared acetylated wood samples had a pronounced hydrophobic character which remained approximately constant after ageing. The predicted W-a between the wood and the adhesives was considerably higher than that between the wood and the thermoplastics. Furthermore, the predicted W-a between the acetylated wood and both the thermoplastics and water was approximately unchanged when comparing the fresh and aged samples. In contrast, the ageing of all other wood samples resulted in a dramatic decrease of the wood-water W-a and a moderate decrease of the wood-thermoplastics W-a. The wood-adhesives W-a, however, was unchanged for the unmodified and furfurylated wood when comparing the fresh and aged samples and even increased for heat treated and acetylated wood samples.