木麻黄树皮提取物对漂白机械浆光致黄化的抑制

Inhibition of Light-induced Yellowing of Bleached Mechanical Pulp with Extracts from Casuarinas Barks

比较了4种木麻黄树皮的提取物对羟自由基的抑制活性,考察了其中活性最大的山地木麻黄的提取物对马尾松漂白机械浆光致黄化的抑制作用。结果表明,强制光照4 h后,涂有山地木麻黄提取物纸片的白度减小了8.6%,而空白纸片的白度减小了19.2%,显示木麻黄提取物对漂白机械浆光致黄化的抑制作用,但强制光照24 h后,纸片白度基本相同。含有质量分数为0.01%和0.03%的木麻黄提取物的碳酸钙涂布液可大幅减轻漂白机械浆的光致黄化,强制光照24 h后,涂布纸片的白度减小约10%。木麻黄提取物抑制羟自由基的活性越大,其对漂白机械浆光致黄化的抑制作用也越大。

Inhibition activities of the extracts from four kinds of Casuarinas bark to hydroxyl radicals were compared.The extract from C.junghuhniana bark was with the highest activity,and was used to inhibit light-induced yellowing of bleached mechanical pulp.ISO brightness of the sheet coated with the extract reduced by 8.6%,compared to 19.2% of the control sheet sample after light irradiation for 4 h.The results showed the inhibiting performance of the extract to the light-induced yellowing.But the brightness of the sheets coated with and without the extract was almost the same after light irradiation for 24 h.The coatings containing CaCO3 and 0.01% and 0.03% ACH showed excellent inhibiting performance to the light-induced yellowing.The ISO brightness of the sheet coated with the coatings reduced by 10% after light irradiation for 24 h.The higher the inhibition activity of the extracts to hydroxyl radical was,the better the inhibiting performance of the coatings to the light-induced yellowing was.