可逆交联聚乙烯醇水凝胶的构筑及其性能评价

Preparation and Properties Evaluation of Reversible Cross-linked Polyvinyl Alcohol Hydrogels

基于氢键作用以没食子酸(GA)和聚乙烯醇(PVA)构筑了一种可逆交联的PVA水凝胶。评价了水凝胶的成胶性能、破胶性能和流变性能。结果表明,当GA含量达到30mg/mL,GA与10%的PVA溶液能够交联形成水凝胶,随着GA含量的增加,成胶时间逐渐降低。在一定温度刺激下,水凝胶能够实现破胶,GA含量越高,破胶时间越长,升高温度能够显著降低破胶时间。流变结果表明,随着GA含量的增加,水凝胶的储能模量和耗能模量均增加。当GA含量高于40mg/mL时,水凝胶的强度达到临界值,具有较好的频率稳定性。综上,热可逆性能的PVA水凝胶在油田暂堵领域具有潜在的应用价值。

A reversible cross-linked PVA hydrogel was constructed by gallic acid(GA)and polyvinyl alcohol(PVA)based on hydrogen bonding.The gelation properties,gel-breaking properties and rheological properties of the hydrogels were evaluated.The results showed that when the content of GA reached 30 mg/mL,hydrogels could be formed with GA and 10%PVA solution.With the increase of GA content,the gelation time gradually decreased.The hydrogel can achieve a gel-breaking process under higher temperatures.The higher the GA content,the longer the gel breaking time.And increasing temperature could significantly reduce the gel-breaking time of the hydrogel.The rheological results showed that the storage modulus and loss modulus of the hydrogel increased with the increase of GA content.When the GA content is higher than 40 mg/mL,the strength of the hydrogel with good frequency stability reaches the critical value.In summary,the thermally reversible PVA hydrogel has potential application value in the oilfield of temporary plugging.