UPMC Univ Paris 6, UMR 7610, Chimie des Polymères, F-75005 Paris, France, and CNRS, UMR 7610, Chimie des Polymères, F-75005, Paris, France.
Macromol Rapid Commun. 2013 Oct;34(19):1524-9. doi: 10.1002/marc.201300410. Epub 2013 Aug 23.
In this study, aqueous emulsion polymerization of n-butyl acrylate is performed in batch conditions without surfactants using a poly(acrylic acid)-trithiocarbonate macro-RAFT agent to control the polymerization and to stabilize the emulsion. According to the polymerization-induced self-assembly (PISA) approach, well-defined amphiphilic PAA-b-PBA diblock copolymers form and self-assemble during synthesis to yield highly stable core-shell particles with an extremely thin hard PAA shell. For the first time, we report here the specific properties of films obtained from these particular latexes. After drying the aqueous dispersion, tough and transparent films are obtained. Although the films are not chemically cross-linked, they do not dissolve in good solvents for PBA. Moreover, they remain transparent even after immersion in water. Rheology shows that the films are both stiff and ductile, thanks to the nanostructured but very low volume fraction (less than 3 wt%) of PAA forming a percolating network in the soft PBA. Compared with conventional core-shell-based films, this approach affords for the first time a route to a thin percolating honeycomb nanostructure with a sharp and strong interface between the two phases. The versatility of the synthetic procedure opens perspectives for a large range of functional materials.
在这项研究中，采用一种聚（丙烯酸）-三硫代碳酸酯大分子 RAFT 试剂，在无表面活性剂的条件下，通过间歇式乳液聚合制备了 n- 丁基丙烯酸酯。该试剂不仅可以控制聚合反应，还可以稳定乳液。根据聚合诱导自组装（PISA）的方法，在合成过程中形成了具有良好定义的两亲性 PAA-b-PBA 嵌段共聚物，并自组装成具有极薄的硬 PAA 壳的高度稳定的核壳粒子。本文首次报道了这些特殊胶乳所得到的薄膜的特殊性能。干燥水乳液后，得到坚韧透明的薄膜。尽管这些薄膜未经化学交联，但它们不溶解于 PBA 的良溶剂中。此外，它们即使在水中浸泡后仍保持透明。流变学表明，由于形成在软 PBA 中具有渗透网络的 PAA 的纳米结构但体积分数非常低（小于 3wt%），这些薄膜既坚硬又具有韧性。与传统的基于核壳的薄膜相比，这种方法首次提供了一种制备具有尖锐强界面的薄渗透蜂窝状纳米结构的途径。这种合成方法的多功能性为各种功能材料开辟了前景。
