一种可光响应超分子弹性体的制备与研究

Preparation and Investigation of a Photoresponsive Supramolecular Elastomer

以甲基丙烯酸月桂酯(LMA)和甲基丙烯酸二甲氨基乙酯(DMAEMA)为单体,采用自由基聚合合成其共聚物,利用碘甲烷(CH3I)对其离子化,加入含偶氮苯类基团的小分子,通过超分子作用形成三维网络结构,获得了一种具有潜在光响应性的弹性体。考察了弹性体的力学及光响应性能,结果表明,在引入偶氮苯小分子后,其交联密度增加,拉伸模量得到了明显提高,但断裂伸长率有所降低,在较大拉伸形变时会发生明显的永久塑性形变。此外,这种弹性体在溶液中具有光致可逆性。在紫外光照射下,发生光致异构化,且速度较快,然后将光源换成可见光,其光致异构化逐渐回复,但速度较慢,且无法完全恢复到紫外光照前的状态。

A parent copolymer was synthesized with lauryl methacrylate(LMA) and 2-(diethylamino) ethyl methacrylate(DMAEMA) by free radical polymerization. The dried parent copolymer was quaternized with iodomethane, followed by complexation with an azobenzene small molecule that forms a three-dimensional network structure by supramolecular action, an elastomer with potential light responsiveness was obtained. The mechanical and photoresponsive properties of the elastomers were investigated. The results show that the cross-linking density and the tensile modulus of the elastomer increase obviously, and the elongation at break decreases and the permanent plastic deformation occurs at larger tensile deformations, when the azobenzene small molecules are introduced. In addition, the elastomer shows an obvious photoresponsive behavior in solution. The photoisomerization occurs at a faster rate with UV irradiation, when the light source is changed to visible light, the photoisomerization gradually recovers, but the speed is slower and cannot be completely restored to the state before UV irradiation.