Optimizing the Conditions of Cationic Polyacrylamide Inverse Emulsion Synthesis Reaction to Obtain High–Molecular–Weight Polymers

Abstract

Cationic polyacrylamide (CPAM) emulsifier is widely applied in the wastewater treatment industry, mining industry, paper industry, cosmetic chemistry, etc. However, optimization of input parameters in the synthesis of CPAM by using the traditional approach (i.e., changing one factor while leaving the others fixed at a particular set of conditions) would require a long time and a high cost of input materials. Onsite mass production of CPAM requires fast optimization of input parameters (i.e., stirring speed, reaction temperature and time, the amount of initiator, etc.) to minimize the production cost of specific–molecular–weight CPAM. Therefore, in this study, we synthesized CPAM using reverse emulsion copolymerization, and proposed response surface models for predicting the average molecular weight and reaction yield based on those input parameters. This study offers a time–saving tool for onsite mass production of specific–molecular–weight CPAM. Based on our response surface models, we obtained the optimal conditions for the synthesis of CPAM emulsions, which yielded medium–molecular–weight polymers and high conversion, with a reaction temperature of 60–62 °C, stirring speed of 2500–2600 rpm, and reaction time of 7 h. Quadratic models showed a good fit for predicting molecular weight (Adj.R2 = 0.9888, coefficient of variation = 2.08%) and reaction yield (Adj.R2 = 0.9982, coefficient of variation = 0.50%). The models suggested by our study would benefit the cost–minimization of CPAM mass production, where one could find optimal conditions for synthesizing different molecular weights of CPAM more quickly than via the traditional approach.

Influence of Alkyl Chain Length on the Performance of Inverse Emulsion Polyacrylamide Fracturing Fluid Thickeners

“…The tensile vibration absorption peak of C–C was observed at 1189 cm –1 . Additionally, the expansion vibration peak of CO in the amide group was identified at 1661 cm –1 . The −SO 3 2– exhibited distinct symmetrical and asymmetric absorption peaks at 1129 and 1044 cm –1 , respectively.…”

“…Additionally, the expansion vibration peak of C�O in the amide group was identified at 1661 cm −1 . 40 The −SO 3 2− exhibited distinct symmetrical and asymmetric absorption peaks at 1129 and 1044 cm −1 , respectively. The bending vibration of the longchain methylene was observed at 780 cm −1 , indicating the presence of the target group within the product.…”

Optimization Conditions to Obtain Cationic Polyacrylamide Emulsion Copolymers with Desired Cationic Degree for Different Wastewater Treatments

“…Previous research utilized response surface models to optimize the conditions for high-molecular-weight CPAMs, and high conversion rate and flocculation efficiency [ 7 , 10 , 12 , 14 , 35 , 36 ]. While molecular weight, conversion rate, and flocculation efficiency are crucial factors in CPAM production, the market demands CPAMs with varying cationic degrees for different purposes and price points.…”

“…Compared to studies that use single-factor experiments to optimize the synthetic conditions for CPAMs [4,10,26,34], our study will save time and materials because our models reduce the number of experiments required to optimize the conditions for the desired CPAMs, while the single-factor approach requires more experiments to optimize each input parameter. Previous research utilized response surface models to optimize the conditions for highmolecular-weight CPAMs, and high conversion rate and flocculation efficiency [7,10,12,14,35,36]. While molecular weight, conversion rate, and flocculation efficiency are crucial factors in CPAM production, the market demands CPAMs with varying cationic degrees for different purposes and price points.…”

“…The grafting approach in CPAM synthesis results in a biodegradable but unstable product with a short shelf life [ 3 ]. A more efficient method for producing CPAMs with a high molecular weight, faster reaction rate, higher conversion efficiency, and simpler temperature control is through free radical polymerization by inverse emulsion [ 3 , 4 , 5 , 6 , 7 ].…”