水凝胶贴剂基质交联机制的研究

制备各类水凝胶贴剂基质,考察其流变行为,研究其交联机制,为水凝胶贴剂产业的进一步发展奠定理论基础并提供较深层次的技术支持。在流变仪振荡模式的条件下,对水凝胶基质进行振幅扫描和单频扫描。分析水凝胶基质的线性黏弹区、复合模量值以及复合模量与相位角随时间的变化斜率,结果发现,凝胶基质的稳定性主要取决于凝胶骨架;交联剂只有在酸性环境下才能与凝胶骨架发生交联反应,以增加凝胶基质的弹性;加入调节剂会降低凝胶基质的弹性,其降低程度与调节剂化学结构中羧基与羟基的个数比(–COO?/–OH)有关。在比值不等的情况下,–COO?/–OH越大,凝胶基质弹性下降越小;在凝胶基质中,调节剂主导基质交联速度,使用不同调节剂的凝胶基质的交联速度由大到小排序为:酒石酸基质>乳酸基质>苹果酸基质>柠檬酸基质。凝胶基质的交联反应不是匀速完成的。

Cross-linking mechanism of the matrix of hydrogel patch

In this study, we prepared various matrices of hydrogel patches and studied their cross-linking mechanism by observing their rheological properties, which could provide theoretical basis and deep technical support for further industrial development of hydrogel patch. Rheology method was used to do the amplitude scanning and single-frequency scanning for various hydrogel matrix, under the condition of oscillation mode of the rheometer. Then the linear viscoelastic region, composite modulus value, as well as changes in slope with time of the composite modulus and phase angle of various hydrogel matrix were analyzed in detail. The results showed that the stability of matrix was mainly determined by hydrogel frame; only in acidic environment, the cross-linking reaction between cross-linker and hydrogel frame can occur; elasticity of matrix can be decreased by organic acid and the effect level was related to the ratio of the number of carboxyl and hydroxyl (-COO(-)/-OH) in adjusters: if the ratio was not equal, the higher -COO(-)/-OH in adjusters would be the less elasticity of matrix decreased; the cross-linking speed of matrix was determined by adjuster, the cross-linking speed of matrix contain different adjusters was ranged in following order: matrix containing tartaric acid > matrix containing lactic acid > matrix containing malic acid > matrix containing citric acid; the cross-linking speed of matrix was not uniform in the whole cross-linking process.