Research On Viscosity And Degradation Of Polyacrylamide (PAM)

Polyacrylamide (HPAM) has played a vital role in enhancing recovery as the oil displacement agent. According to the characteristics of polymer flooding, a full review of the condition of oil-field waste water of polymer flooding and its treatment technology is presented. As is known, the low efficiency of polymer flooding is caused by the viscosity reduction and degradation of polyacrylamide (PAM). There are many methods to measure the concentration of HPAM. In this paper, the concentration of HPAM was examined by using the turbidity method. and starch-cadmium iodine According to many experiments ,we analyze the factors which may have influences on the absorbency such as the react time, relative molecular weight, the degree of mineralization and trivalence metal ions,the optimum factor was summarized. The factors of interfering test and corresponding elimitation method based on these were also put forward.The viscosity is an important parameter which shows the stability of HPAM in aqueous solution. It may be noted that the smaller the loss percentage of the viscosity is, the better the stability of HPAM is. In practice, the viscosity of the polymer are affected by many factors such as shearing action, hot function, salty function, which also lead to the change of the recovery efficiency. The result of the concentration of PAM by turbidity showed that the larger the molecular weight was, the higher was the viscosity. There was an increase trend of the viscosity with the augment of HPAM concentration and decrease of agitating rate. It can be also concluded that the divalent metal ions was more effective in reducing the viscosity than monovalent metallic ions. With the addition of acid or alkali, the viscosity decreased obviously as well. The results showed that when the value of PH was more than 6.0, the stability of HPAM was better. Besides, the viscosity of HPAM decreased as the hydrolysis degree ascended to 30.6%.The result of the concentration of HPAM by starch-cadmium iodide method showed that the pH of buffer solution was 5.0, the dosage of bromine water was 2mL, the reaction time was 10min, the reaction time was 5min with addition of sodium formate, the reaction time was 10min with addition of starch-cadmium iodide, the volume of sodium fomate was 5mL and the detection ranged from 4.5 to 100 mg/L. The degradation products of polyacrylamides were characterized and analyzed by high-performance liquid chromatography, UV spectra and infrared spectra. It can be concluded that the mechanism of polyacrylamide degradation was radical mechanism. The main products of oxidative degradation of polyacrylamide were small molecule organic acids namely acrylamide and acrylic acid, and then furtherly degraded into small inorganic molecules.