The present study aims to evaluate the effect of the monomer-to-comonomer ratio (1.00, 1.25, 1.50, 1.75, 2.00) on the swelling kinetics and diffusion behavior of a hydrogel. In this study, hydrogels with different ratios were prepared by inverse suspension polymerization using acrylic acid (AA) as the monomer and acrylamide (AM) as the comonomer with a fixed amount of AM. The chemical, morphological and thermal properties of the hydrogels were also analyzed. Swelling analyses showed that the hydrogels followed second-order swelling kinetics, while for the diffusion behavior, the hydrogels obeyed Fickian diffusion with n values less than 0.5. Hydrogel_1.5 showed the lowest n value with the presence of strong broad O–H stretching for carboxylic acid. The thermogravimetric analysis showed that Hydrogel_1.5 had the highest thermal stability compared with other ratios. In conclusion, Hydrogel_1.5 is a potential starting ratio for AA-co-AM hydrogel by inverse suspension polymerization for future development.

中文翻译：

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丙烯酸/丙烯酰胺比例对溶胀动力学和扩散行为的评价

本研究旨在评估单体与共聚单体的比例（1.00、1.25、1.50、1.75、2.00）对水凝胶的溶胀动力学和扩散行为的影响。在这项研究中，使用丙烯酸（AA）作为单体，丙烯酰胺（AM）作为共聚单体，以固定的AM量通过逆悬浮聚合制备了不同比例的水凝胶。还分析了水凝胶的化学，形态和热性能。溶胀分析表明，水凝胶遵循二级溶胀动力学，而对于扩散行为，水凝胶遵循Fickian扩散，n值小于0.5。Hydrogel_1.5的最低n羧酸在强的OH拉伸作用下具有很高的价值。热重分析表明，与其他比例相比，Hydrogel_1.5具有最高的热稳定性。总之，对于未来的发展，通过逆悬浮聚合，水凝胶_1.5是AA- co- AM水凝胶的潜在起始比率。