Sensitive Mechanoluminescent Polymeric Materials:Design,Synthesis And Applications

Polymers and their composites are widely used in various fields.With the rapid development of mechanochemistry,preparing sensitive mechanoresponsive polymeric materials and investigating their mechanical behaviors are very important for the rational use of materials and risk aversion.Aimed at the design,synthesis and applications of highly sensitive mechanoluminescent polymeric materials,two kinds of mechanochemiluminescent polymers,including polyurethane/fluorescence halloysite nanotubes composite materials(PU/HNTs-Ben)and β-diketone dyes containing PDMS elastomers were synthesized.Their optomechanical properties and applications as stress sensor were studied.The results can be summarized as follows:1.The fluorescent halloysite nanotubes(HNTs-Ben)and mechanochemiluminescent PU/HNTs-Ben were synthesized,and characterized by fourier transform infrared spectroscopy(FTIR),UV-visible spectroscopy,thermogravimetric analysis(TGA),scanning electron microscope(SEM)and transmission electron microscope(TEM),and the mechanoluminescent behavior of composite films was further studied by optomechanical measurements.The HNTs-Ben introduced in polymer matrix greatly increased the mechanical strength of the materials.Acting as energy transfer acceptor,it not only enhanced the light intensity but also modulated luminescent color during fracture process.Our study thus enriched mechanochemiluminescent composites,allowing sensitive visualization of stress distribution in composites during the tensile process,and provided new ideas for the study of fracture mechanism of polymer composites.2.Boron containing β-diketone dyes BF and BCN,as the intra-chain energy transfer acceptor units,were incorporated into 1,2-dioxetane containing mechanochemiluminescent PDMS.Optomechanical properties of these crosslinked mechanochemiluminescent elastomers were studied.This kind of mechanochemiluminescent polymer films can be prepared in a simple way and can efficiently emit light under mechanical force.We further studied the effects of acceptor contents and species on light intensity and colors.This work provides new ideas for the preparation of mechanochemiluminescent elastomers with high sensitivity.