There are many polyacrylamide models, and the molecular weight of each model is also different, some products can reach more than 10 million molecular weight, and some products have only a few million molecular weight. The molecular weight of the cationic polyacrylamide is lower than the molecular weight of the anion, then how to determine its molecular weight, the use of 58.5g/L sodium chloride solution to prepare the sample into a dilute solution, with the Uloch viscometer to determine its characteristic viscosity, according to the empirical formula to calculate its molecular weight, the specific method can refer to the national standard or enterprise standard. When testing, some testing instruments need to be used, such as electronic analytical balance, magnetic stirrer, Ulster viscometer, constant temperature water bath, liquid chromatograph, etc.
The detection of polyacrylamide molecular weight is more complex, the error of the detection results is relatively large, and the price of some instruments is not cheap, most of the end customers do not have this detection ability. Many people in this area there is a misunderstanding, will think that the higher the molecular weight of the product effect is better, in fact, this is not necessarily the case, such as sewage sludge dehydration is cationic, the molecular weight is not so high, but the molecular weight of anion is relatively high, if only to high molecular weight, choose anion can be, In fact, it is not effective to use anion to press mud in municipal sewage treatment plants.
The effect of polyacrylamide this product is not good, and is not determined by the molecular weight, in addition to the often said molecular weight, anion and hydrolysis degree, cation and ion degree and other indicators. The effect is good or not to be judged by the selection experiment of polyacrylamide, in the actual use of the process to first through the small test selection, with different models of products to do cup and bottle comparison experiment, in the same amount of addition, to see which model of the product effect is the best, so as to determine. It is then verified in the actual production process. So the choice of polyacrylamide, selection is very important.
