Li Longfei,Chen Lin,Liu Weifeng,Yang Yongzhen,Liu Xuguang,Chen Yongkang
5-Fluorouracil surface-imprinted thermosensitive magnetic microspheres were prepared by using Fe 3 O 4 -encapsulating carbon microspheres as cores, N -isopropylacrylamide as thermosentitive monomer, ammonium persulfate as initiator, N , N ′-methylenebisacrylamide as crosslinker, and 5-fluorouracil as template molecule. The formation of these hybrid microspheres was verified by field emission scanning electron microscopy, transmission electron microscopy, Fourier transformation infrared spectroscopy, thermogravimetry, and dynamic light scattering. The results of the latter measurements show that the as-synthesized microspheres have a hydrodynamic diameter of 326 nm with the lower critical solution temperature of around 43 °C. The obtained microspheres are magnetic and show good potential for controlled loading and release of 5-fluorouracil. Graphical abstract
Shape-memory polymers are important smart materials with potential applications in smart textiles, medical devices, and sensors. We prepared trans-1,4-polyisoprene, low-density polyethylene (LDPE), and high-density polyethylene (HDPE) shape-memory composites using a simple mechanical blend method. The mechanical, thermal, and shape-memory properties of the composites were studied. Our results showed that the shape-memory composites could memorize 3 temporary shapes, as revealed by the presence of broad melting transition peaks in the differential scanning calorimetry curves. In the trans-1,4-polyisoprene/LDPE/HDPE composites, the cross-linked network and the crystallization of the LDPE and HDPE portions can serve as fixed domains, and all crystallizations can act as reversible domains. We proposed a schematic diagram to explain the vital role of the cross-linked network and the crystallization in the shape-memory process.
危险品化学品经营许可证（带存储）