Synthesis of an amphoteric polymer as a high‐temperature‐resistant shale stabilizer in water‐based drilling fluids

Synthesis of water soluble ionic liquid copolymers based on acrylamide and investigation of their properties in flocculating of clay suspensions

To overcome water absorption and swelling by clay mineral layers, it is very important to develop stabilizing additives for water-based drilling fluids, where organic polymers are used as raw materials. Acrylamide copolymers, acting as flocculating agents, have the potential to separate minerals such as montmorillonite. In this study, three water-soluble copolymers containing acrylamide-amphoter, acrylamide-amphoter-anion, and acrylamide-amphoter-cation were synthesized and characterized using various analytical techniques, including Fourier-transform infrared spectroscopy, nuclear magnetic resonance, gel permeation chromatography, differential scanning calorimetry, thermogravimetric analysis, and derivative thermal gravimetric techniques. These copolymers were employed as flocculants to treat water suspensions containing montmorillonite particles, and a range of analytical methods, such as sedimentation volume measurement, scanning electron microscopy analysis, X-ray diffraction analysis, and contact angle measurement, were employed to identify the relationship between inhibitive performance. The flocculation of montmorillonite plates was attributed to the electrostatic attractions between montmorillonite and the synthesized copolymers. High molecular weight copolymers offer greater thermal stability and better flocculation characteristics for water-based drilling fluids. Among the tested copolymers, the acrylamide-amphoter-anion sample, with the highest molecular weight, exhibited the best performance as a coagulant when compared to the other copolymers.

Application of amphoteric polymers in the process of leather post-tanning

Abstract

With the characteristics of controllable charge and environmental friendliness, amphoteric polymers can be used in post-tanning process to solve the problems that arise during leather making and are caused by the low absorption rate of single-charge chemicals, incompatibility with new tanning methods, and complex operation process. In this review, the structure, performance, and preparation of amphoteric polymers are reported. Then, the charge change of collagen during different tanning and pH treatments is introduced. Finally, the application and development of amphoteric polymers during the post-tanning process of leather making are discussed. This review has certain guiding significance to the preparation and application of amphoteric polymers for tanning system.

Graphical abstract