Ghosh Biswajit, Urban Marek W
School of Polymers and High Performance Materials, Shelby F. Thames Polymer Science Research Center, University of Southern Mississippi, Hattiesburg, MS 39406, USA.
Science. 2009 Mar 13;323(5920):1458-60. doi: 10.1126/science.1167391.
Polyurethanes have many properties that qualify them as high-performance polymeric materials, but they still suffer from mechanical damage. We report the development of polyurethane networks that exhibit self-repairing characteristics upon exposure to ultraviolet light. The network consists of an oxetane-substituted chitosan precursor incorporated into a two-component polyurethane. Upon mechanical damage of the network, four-member oxetane rings open to create two reactive ends. When exposed to ultraviolet light, chitosan chain scission occurs, which forms crosslinks with the reactive oxetane ends, thus repairing the network. These materials are capable of repairing themselves in less than an hour and can be used in many coatings applications, ranging from transportation to packaging or fashion and biomedical industries.
聚氨酯具有许多使其成为高性能聚合物材料的特性，但它们仍然容易受到机械损伤。我们报道了一种聚氨酯网络的开发，该网络在暴露于紫外光时表现出自我修复特性。该网络由一种含氧杂环丁烷取代的壳聚糖前体组成，该前体被引入到一种双组分聚氨酯中。当网络受到机械损伤时，四元氧杂环丁烷环打开形成两个反应端。当暴露于紫外光时，壳聚糖发生链断裂，与反应性氧杂环丁烷端形成交联，从而修复网络。这些材料能够在不到一小时的时间内自我修复，可用于许多涂料应用，从运输到包装、时尚和生物医学行业。
