Max Planck Institute for Polymer Research, 55128 Mainz, Germany.
Institut für Chemie neuer Materialien, Universität Osnabrück, D-49069 Osnabrück, Germany.
Sci Adv. 2023 May 10;9(19):eadg8865. doi: 10.1126/sciadv.adg8865.
Semicrystalline polymers are solids that are supposed to flow only above their melting temperature. By using confinement within nanoscopic cylindrical pores, we show that a semicrystalline polymer can flow at temperatures below the melting point with a viscosity intermediate to the melt and crystal states. During this process, the capillary force is strong and drags the polymer chains in the pores without melting the crystal. The unexpected enhancement in flow, while preserving the polymer crystallites, is of importance in the design of polymer processing conditions applicable at low temperatures, e.g., cold drawn polymers such as polytetrafluoroethylene, self-healing, and in nanoconfined donor/acceptor polymers used in organic electronics.
半结晶聚合物是仅在其熔点以上才会流动的固体。通过在纳米级圆柱形孔内进行限制，我们证明了半结晶聚合物可以在低于熔点的温度下流动，其粘度介于熔体和晶体状态之间。在这个过程中，毛细力很强，将孔中的聚合物链拖曳过去，而不会使晶体熔化。在保持聚合物微晶的同时，这种出乎意料的流动增强对于设计适用于低温的聚合物加工条件非常重要，例如聚四氟乙烯等冷拉伸聚合物、自修复聚合物以及用于有机电子学的纳米受限供体/受体聚合物。
