剪切条件下铬冻胶体系动态成胶研究

Research on Dynamic Gelling Process of HPAM/Cr(Ⅲ) under Shearing

在75℃条件下,分别在IKA搅拌器和振荡器剪切下研究了铬冻胶的动态成胶情况。结果表明,成胶液在剪切条件下可以形成不连续冻胶,其成胶时间随剪切速率的增大而延长,所成冻胶黏度随剪切速率的增大而降低。与静态条件成胶相比,剪切条件下开始成胶的时间延长,冻胶黏度降低。IKA搅拌剪切下,聚合物含量为0.2%、交联剂为0.02%Na2Cr2O7+0.04%Na2SO3的成胶液不能成胶,交联剂为0.04%Na2Cr2O7+0.08%Na2SO3、0.06%Na2Cr2O7+0.12%Na2SO3的2种常用配方成胶液的临界成胶剪切速率分别为27.08 s-1和35.20 s-1;IKA振荡剪切下,聚合物含量为0.2%,交联剂为0.02%Na2Cr2O7+0.04%Na2SO3、0.04%Na2Cr2O7+0.08%Na2SO3、0.06%Na2Cr2O7+0.12%Na2SO3的3种常用配方成胶液的临界成胶剪切速率分别为10.47 s-1、17.28 s-1、20.94 s-1;75℃下,配方为0.2%HPAM+0.04%Na2Cr2O7+0.08%Na2SO3的成胶液,IKA搅拌剪切下的临界剪切成胶时间为1.5 h,IKA振荡剪切下的临界剪切成胶时间为4 h。

The dynamic gelling process of HPAM/Cr（Ⅲ） system was investigated under the shear of IKA blender and IKA oscillator at the temperature of 75℃.The results showed that the gel formed under shearing action was incontinuous;the stronger shearing strength was,the longer the time required for a gel to form was,and the lower the viscosity of the formed gel was.Compared with the gelling process under static conditions,the time required for a gel to form was delayed,and the viscosity of the formed gel was lower.When the polymer concentration was 0.2% and the crosslinker was 0.02%Na2Cr2O7＋0.04%Na2SO3,the gel could not be formed under the shearing of IKA agitator;and the critical shearing rates of the common gelling solution containing 0.04%Na2Cr2O7＋0.08%Na2SO3 or 0.06%Na2Cr2O7＋0.12%Na2SO3 crosslinkers were 27.08 s-1 and 35.20 s-1,respectively.Under the shearing of IKA oscillator,when the polymer concentration was 0.2%,and the critical shearing rates of three common gelling solutions containing the crosslinkers of 0.02%Na2Cr2O7＋0.04%Na2SO3,0.04%Na2Cr2O7＋0.08%Na2SO3 and 0.06%Na2Cr2O7＋0.12% Na2SO3,respectively,were 10.47 s-1,17.28 s-1and 20.94 s-1 respectively.At the temperature of 75℃,the critical gelation time of the gelling system 0.2%HPAM＋0.04%Na2Cr2O7＋0.08%Na2SO3 was 1.5 h under the shearing of IKA agitator,while that was 4 h under the shearing of IKA oscillator.