由于嵌段共聚物是制备纳米材料的可能途径之一受到广泛重视,它可以通过自组装而形成具有诸如球状、柱状及层状等复杂的形态结构,嵌段共聚物作为增容剂已经被大量应用在热塑性聚合物的共混改性中,但用两亲性嵌段共聚物改性热固体聚合物,如环氧树脂及不饱和聚酯等方面的工作则相对较少.Bates等在1997年首次使用双亲性嵌段共聚物增韧改性环氧树脂,可形成具有纳米结构的高性能聚合物材料.近年来,由于上述方法成为制备纳米结构热固性聚合物材料的有效途径而倍受关注,在这一领域开始有较多的文献报道.与嵌段共聚物/热塑性聚合物共混物不同,嵌段共聚物/热固性聚合物共混中多种物理与化学因素影响最终材料的结构和性能.例如嵌段共聚物在未固化的低分子量热固性树脂单体中的自组装、热固性树脂的化学交联反应,交联反应过程中的嵌段共聚物与热固性树脂的相分离等.这些因素的影响决定了最终材料的结构和性能.因此,对这类材料结构和动力学的研究具有重要的理论与实际意义.目前,对于含PEO的嵌段共聚物与环氧树脂共混制备纳米结构热固性聚合物的研究在国际上已经有较多的工作报道,
An nanostructured thermoset blend of unsaturated polyester (UPR) and PEO-PPO-PEO triblock copolymer was prepared and characterized by solid-state NMR and other techniques. It is concluded that the blend is microphase separated and the determined long period is 20 nm. A distinct dynamic difference between the cured- UPR matrix and block copolymers was observed by 1D and 2D NMR experiments, the formation of PEO crystalline domains was inhibited in the blend. The PEO blocks are partially miscible with the cured-UPR matrix. Upon curing, part of the mobile PEO was locally expelled from the cured-UPR matrix and formed dispersed microphase together with the mobile PPO, the residual immobilized PEO blocks were intimately mixed with the partially cured-UPR, and they formed an interphase region.