【摘要】 气-液置换法一般用来测定微孔膜的孔径参数，在常温条件下完成.当用于孔隙率的测试时，可以得到微孔膜通孔的孔隙率.以聚乳酸平板膜为对象，开展了气-液置换法测试微孔膜孔隙率的研究，包括测试液体的选择、测试条件的确定、方法精密度和方法比对等.结果表明，升压终点是气-液置换法测试孔隙率的关键控制条件，当湿曲线转变为直线，透过膜气体流量达到孔径测试过程中干、湿曲线交点对应的透过气体流量值后，停止升压，结束气-液置换过程.该方法操作简单、精密度高，是替代热法测定聚乳酸膜等疏水、热不稳定、易分解微孔膜孔隙率的科学适宜方法.更多还原

【Abstract】 The gas-liquid displacement method is usually used to test the pore size parameters of microporous membrane at room temperature.When used for porosity testing, the porosity of through holes of microporous membranes can be obtained.Polylactic acid plate membrane was selected to study the measurement of microporous membrane porosity, including selection of test liquid, determination of test conditions, method precision and method comparison.The results show that the end point of pressure boost is the key control condition of porosity measurement by gas-liquid displacement method.The pressure boost should be stopped to end the gas-liquid displacement process after the wet curve changes into a straight line and the gas flow through the membrane reaches the gas flow value corresponding to the intersection of wet curve and dry curve during the testing proces of pore size.This method can be operated simply and has high precision, which is a scientific and appropriate method to replace thermal method to test the porosity of hydrophobic, thermally unstable and easily decomposed microporous membranes such as polylactic acid membrane.更多还原