Le Hong Tho, Wang Chen-Gang, Goto Atsushi
Division of Chemistry and Biological Chemistry, School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, 637371, Singapore, Singapore.
Angew Chem Int Ed Engl. 2020 Jun 8;59(24):9360-9364. doi: 10.1002/anie.202001544. Epub 2020 Mar 31.
Liquid vinyl monomers were converted into solid crystals via halogen bonding. They underwent solid-phase radical polymerizations through heating at 40 °C or ultraviolet photo-irradiation (365 nm). The X-ray crystallography analysis showed the high degree of monomer alignment in the crystals. The polymerizations of the solid monomer crystals yielded polymers with high molecular weights and relatively low dispersities because of the high degree of the monomer alignment in the crystal. As a unique application of this system, the crystalized monomers were assembled to pre-determined structures, followed by solid-phase polymerization, to obtain a two-layer polymer sheet and a three-dimensional house-shaped polymer material. The two-layer sheet contained a unique asymmetric pore structure and exhibited a solvent-responsive shape memory property and may find applications to asymmetric membranes and polymer actuators.
液态乙烯基单体通过卤素键合转化为固体晶体。它们通过在40 °C加热或紫外线照射（365 nm）进行固相自由基聚合。X射线晶体学分析表明晶体中单体具有高度的排列规整性。由于晶体中单体排列高度规整，固体单体晶体的聚合产生了高分子量且分散度相对较低的聚合物。作为该体系的独特应用，将结晶单体组装成预定结构，然后进行固相聚合，以获得双层聚合物片材和三维房屋形状的聚合物材料。该双层片材具有独特的不对称孔结构，并表现出溶剂响应形状记忆特性，可能应用于不对称膜和聚合物致动器。
