The polymer obtained from hydrophilic monomers can be transformed into a hydrogel via cross-linking by different cross-linkers. Hydrogels are three-dimensional networks that can absorb several times their weight and swell in water/swelling media, improving the media’s viscosity as a thickener. The cross-linked poly(acrylic acid) microparticles prepared via precipitation polymerization technique are often synthesized by radical polymerization and have carboxylic functional groups in their structure, which make the hydrogel properties such as swelling capacity, particle morphology, and viscosity be controlled by physical factors such as solvent, neutralizer, pH, pK a , zeta potential, and ionic strength of the swelling media, as well as synthetic factors including comonomer, cross-linker, and network type. In this paper, the effects of crucial factors on the synthetic and swelling steps are elaborated to facilitate the achievement of poly(acrylic acid)-based xerogels having desirable rheological properties, such as swelling/viscosity optimization, which is the primary purpose of a thickener in any swelling media.

中文翻译：

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合成和物理因素对沉淀聚合技术合成的聚丙烯酸水凝胶性能的影响：综述

由亲水单体获得的聚合物可以通过不同交联剂的交联转化为水凝胶。水凝胶是三维网络，可以吸收其重量数倍的重量并在水/膨胀介质中膨胀，从而提高介质作为增稠剂的粘度。沉淀聚合技术制备的交联聚丙烯酸微粒通常通过自由基聚合合成，其结构中含有羧基官能团，这使得水凝胶的溶胀能力、颗粒形态和粘度等性能受物理因素控制。如溶剂、中和剂、酸碱度,PK A 、zeta 电位和溶胀介质的离子强度，以及包括共聚单体、交联剂和网络类型在内的合成因素。本文阐述了关键因素对合成和溶胀步骤的影响，以促进聚丙烯酸干凝胶的实现，该干凝胶具有理想的流变性能，例如溶胀/粘度优化，这是增稠剂的主要目的在任何膨胀介质中。