酸碱对防止泡桐木材变色的影响

Effects of Acid and Alkali on Discoloration Prevention of Paulownia Wood

对酸碱度影响泡桐木材色泽进行了研究,并对弱碱溶液防止泡桐木材变色的作用做了试验与分析。结果表明:酸碱度影响泡桐木材颜色变化,在偏酸条件下泡桐木材的白度易于向劣化方向发展,总色差升高;偏碱条件下泡桐木材白度提高,总色差下降,色泽指标明显趋好。0.25%的弱碱溶液改善泡桐木材的渗透性,能溶出木材内部部分内溶物,可浸提的内溶物中多含有变色前驱物质,促进了防止泡桐木材的变色作用,而又不会污染泡桐木材材面。防变色剂具有一定的防变色作用,但只用防变色剂预防泡桐木材变色容易出现返色现象,综合使用弱碱溶液与防变色剂防治效果比单独使用防变色剂效果好,经0.25%的弱碱溶液同防变色剂处理可使泡桐木材防变色效果内外趋于一致。

An experiment was conducted to study the effects of acid and alkali on paulownia wood color. The protection of weak base solution against discoloration of paulownia wood was also analysed. Result showed that pH value had influence on paulownia wood color, and white value of paulownia wood was prone to decrease and chromatism rose under acidity condition. White value of paulownia wood increased and chromatism decreased under alkalescence condition, and color and luster obviously tended to be bright. Base solution with concentration of 0. 25% promoted the penetrability of paulownia wood, dissolved some extractives containing discoloration precursor chemicals, and strengthened the discoloration prevention of paulownia wood without contaminating board surface. Anti-discoloration reagents had certain effects on discoloration prevention of paulownia wood, but it would result in discoloration-returning phenomenon when only using it to prevent paulowma wood from discoloration. Weak base soluuons together vath anti-dlscoloration reagents had better effects than antidiscoloratiol reagents, and the control effects on the inside and outside of the wood were consistent after treated with weak base solution of 0.25% with the addition of anti-discoloration reagent.