可以使用不同的交联剂来设计和优化水凝胶特征以满足特定的要求。在这方面,本工作研究了纤维素基水凝胶的物理化学特征,通过使用来自相同缩水甘油家族的不同环氧交联剂设计,即环氧氯丙烷(ECH),1,4-丁二醇二缩水甘油醚(BDDE),和三羟甲基丙烷三缩水甘油醚(TMPTGE)。交联剂的结构(从简单到支化)和官能度(单,研究了水凝胶的双环氧基团和三环氧基团)特征。通过凝胶分数研究了水凝胶的性能,以及ATR-FTIR,DVS,SEM,DSC,和TG分析。此外,研究了水凝胶的溶胀和流变行为。讨论了每种方法的优点和局限性,并建立了交联剂结构与水凝胶性能之间的强相关性。通过ATR-FTIR光谱证明了新醚键的形成。强调的是,孔径直接受交联剂类型的影响,即,它随着交联剂分子中环氧基团数量的增加而减少,即,从46±11.1µm(水凝胶CE,使用ECH)至12.3±2.5µm(水凝胶CB,使用BDDE)和6.7±1.5µm(水凝胶CT,用TMPTGE)。流变行为与溶胀数据和水凝胶形态一致,例如具有最高Qmax和最大孔径的CE比CB和CT相对更具弹性。相反,通过使用具有更复杂结构的交联剂获得的更致密的基质具有更好的热稳定性。实验结果突出了使用特定交联剂的可能性,具有定义的结构和功能,为了确定水凝胶的主要特性,含蓄地,为某个应用领域设计它们。
Hydrogel features can be designed and optimized using different crosslinking agents to meet specific requirements. In this regard, the present work investigates the physico-chemical features of cellulose-based hydrogels, designed by using different epoxy crosslinkers from the same glycidyl family, namely epichlorohydrin (ECH), 1,4-butanediol diglycidyl ether (BDDE), and trimethylolpropane triglycidyl ether (TMPTGE). The effect of the crosslinker\'s structure (from simple to branched) and functionality (mono-, bi- and tri-epoxy groups) on the hydrogels\' features was studied. The performances of the hydrogels were investigated through the gel fraction, as well as by ATR-FTIR, DVS, SEM, DSC, and TG analyses. Also, the swelling and rheological behaviors of the hydrogels were examined. The advantages and limitations of each approach were discussed and a strong correlation between the crosslinker structure and the hydrogel properties was established. The formation of new ether bonds was evidenced by ATR-FTIR spectroscopy. It was emphasized that the pore size is directly influenced by the crosslinker type, namely, it decreases with the increasing number of epoxy groups from the crosslinker molecule, i.e., from 46 ± 11.1 µm (hydrogel CE, with ECH) to 12.3 ± 2.5 µm (hydrogel CB, with BDDE) and 6.7 ± 1.5 µm (hydrogel CT, with TMPTGE). The rheological behavior is consistent with the swelling data and hydrogel morphology, such as CE with the highest Qmax and the largest pore size being relatively more elastic than CB and CT. Instead, the denser matrices obtained by using crosslinkers with more complex structures have better thermal stability. The experimental results highlight the possibility of using a specific crosslinking agent, with a defined structure and functionality, in order to establish the main characteristics of hydrogels and, implicitly, to design them for a certain field of application.