压力对竹材中防腐剂渗透性影响的初步研究

以市售精刨毛竹条为研究对象，通过加压渗透的方式促使甲苯胺蓝染色剂、硫酸铜防腐剂在竹条中快速渗透，分析防腐剂有效成分在竹材中渗透与截留规律。结果显示：随着压力的增大，染料在竹材中的渗透时间急剧减少，渗透速度增大，压力与渗透速度的关系符合Poiseuille公式；当压力为0.2~0.4 MPa时，染料在竹材中明显截留，出液端渗透出的液体接近无色；染料在渗透过程中，竹黄部分的染色效果低于竹青部分，染料在竹青中的渗透距离要大于竹黄；以硫酸铜溶液（CuSO₄）在不同压力和不同浓度下对竹材进行加压浸渍，压力对加压端至0.5 m处的铜含量的降幅影响明显，随竹材长度的增加，竹材中铜含量出现迅速降低—缓慢降低的转变过程。加压浸注防腐剂有利于防腐剂的纵向和横向渗透效率，压力的调控可以促进防腐剂的横向渗透及其在竹材中的截留，渗透效果随渗透距离的增加而降低。

Impact of Pressure on Preservative Permeability in Bamboo

Fine rectangular bamboo strips sold in market were used in study to analyze the permeability and interception of preservatives in bamboo by using Preservative Toluidine CuSO₄ combined with blue stain. The results showed that with the increase of pressure, the time needed for stain to permeate decreased remarkably, and the permeating velocity increased. The relationship between pressure and permeating velocity was in accord with Poiseuille formula. Stain permeating was prevented in bamboo specimens when the pressure was within the range of 0.2 and 0.4 MPa and the solution became almost achromatous at the outflow end of specimens. During permeating, the stain in vascular bundles faded earlier in the outer part than that in inner part of bamboo culm wall. The pressure had significantly impact on Cu content at the first 0.5 m of pressurized end. With the increase of distance from pressurized end, the decrease ratio of Cu content was high at the beginning and then became less and decreased exponentially. It can concluded that pressure could increase the permeating efficiency of preservatives, the regulation of pressure could promote the horizontal permeability and interception of preservatives in bamboo, and the permeability effect would decrease with the increasing permeability distance.