染色木材pH值与缓冲容量的比较分析

Comparative Analysis on pH and Buffering Capacity of Dyed Wood

分别用酸性染料与活性染料,对大青杨和桦木单板进行直接染色和NaOH溶液预处理后染色,测量2种染色单板的pH值和缓冲容量,并与未染色单板进行对比。结果表明,NaOH溶液预处理、酸性染料、活性染料的染色对2种单板的pH值及缓冲容量的影响规律一致;染色可小幅度增加木材pH值,显著降低酸缓冲容量;预处理则可较大幅度增加pH值,并一定程度上增加酸缓冲容量;大青杨单板经2种工艺染色后,其酸缓冲容量均有明显下降;桦木单板直接染色酸缓冲容量减小,而预处理后染色则酸缓冲容量增大。

Acid dye and reactive dye were applied to veneer from Ussuri Poplar and birch respectively;NaOH solution was used as a pretreatment reagent. The pH and buffering capacity of the dyed wood were determined to compare with that of the plain wood. The results demonstrated that the effects of NaOH solution pretreatment and the dyeing process on pH and buffering capacity were similar for the two types of wood. The dyeing process resulted in a small increase of the pH of the wood, but a distinct decrease of the acid buffering capacity. The pretreatment with NaOH solution increased the pH of the wood significantly,and the acid buffering capacity of the wood also increased during the same process. The acid buffering capacity of the Ussuri Poplar decreased signifi cantly by either dyeing directly or dyeing after pretreating with NaOH solution. The acid buffering capacity of birch veneer decreased by dyeing directly and increased by dyeing after pretreating with NaOH solution.