木材的pH值和缓冲容量

<正>本试验用平衡图解法和回流抽提法测定木材的pH值,探求测定结果与木材真pH值相符的测定方法。主要测定了意杨新品种“63”、“69”,“72”和毛白杨木材的pH值和缓冲容量,为更合理地利用这些优良速生树种的木材提供依据。

STUDIES ON THE WOOD pH AND BUFFERING CAPACITY OF HYBRID POPLARS

Hybrid poplars grow fast and are widespread in our country. Researches concerning making plywood and particleboard out of poplars are in full swing. Wood pHand buffering capacity are important properties of wood; they influence gluability of wood. The aim of our experiments was to promote proper and effective utilization of poplar wood.To determine the true pH of wood, an appropriate method should be selected. We studied this question and deliberately adopted the water-extraction and graphical equilibrium method. The hybrid poplars used in this experiment had been growing in our college campus.The results of our determination are as follows:( 1 ) The average wood pH of 1-63/51 is 7.13,( 2) That of 1-69/55 is 6.71,( 3) That of 1-72/58 is 6.81,(4) That of Populus tomer.tosa is 6.51.The milligram equivalent of sulfuric acid required to reduce the pH of a litre of wood extract solution of hybrid poplars from the starting value to 5 is 1.44. The milligram equivalent of sodium hydroxide required to raise the pH of the solution from the starting value to 10 is 1.94. The sum of these two values, i.e., 3.38, makes the total buffering capacity.Regression analyses of pH variations of poplar wood extract solution added to nominal 0.0250N sulfuric acid or sodium hydroxide solution are also given in this report. The regression equations can offer relatively high prediction capacities which are:1 ) When pH is below 5,Y = 5.4385+ 0.1918X;2 ) When pH is above 5,