Synthesis, Properties And Assembly Behaviors Of Amido Functionalized Polysiloxane

Amidofunctionalized polysiloxanes, possessing a variety of unique and superior properties, play important roles in modifitions of organic polymers, such as the copolymerization of polysiloxanes and organic polymers, with the aid of the reaction activity of the aminofunctional groups, to endow the organic polymers with the excellent properties of the polysiloxanes. With the rapid development of these kinds of polymer in silicone chemistry, amido functionalized polysiloxanes have been widely applied in many research fields. However, their applications are limited to some extent due to the decomposition or rearrangement under certain conditions. So understanding their rearrangement conditions and mechanisms will be of great important values for the control, improvement and application of these compounds. At the same time, the introductions of amido (acylamido) groups in main chains of polysiloxanes have aroused great interest. To our best knowledge, lanthanide ions can exhibit their excellent photophysical abilities under UV light excitation because of their unique electron configurations. Therefore, the properties of the materials can be improved by covalently grafting the lanthanide complexes to the polysiloxane backbone. The organic ligands can reinforce the energy absorption efficiency and the inorganic portions of the structure offer good mechanical properties. Thus, some stable composite materials with excellent luminescent propertities were prepared in the modification process, by grafting the lanthanide complexes to organopolysiloxanes via chemical bonds. To some extent, the applications of polysiloxanes were developed.A series of amino functionalized polysiloxanes have been synthesized and characterized in ring-opening polymerization with materials of coupling agent (AEP), octamethylcycoltetrasiloxane (D4) and hexamethyldisiloxane (MM). Thermal degradation behaviors have been investigated by Infrared Spectrometry (IR), Thermogravimetric analysis (TGA) and Pyrolysis-Gas Chromatography-Mass Spectrometry (PY-GC-MS) in N2 and air atmosphere. The results show that amido groups in side chain influence the thermal stability. The decomposition processes, which took place in both intramolecular chains and intermolecular chains, are mainly biting-back reactions. And the process is divided into two stages ranging from 100℃to 350℃and 400℃to 800℃with the formation of oligomers. Since the atmospheres impact on the structures of thermal degradation products, two thermal degradation mechanisms of aminopolysiloxanes are proposed.Amidopolysiloxanes matrixes were modified by acylamidation reactions to prepare some luminescent polysiloxanes (side chain acylamidopolysiloxane, terminated acylamidopolysiloxane and acylamidoresin)-rare earth composite materials. Narrow-width green emissions are achieved for Tb3+ and Dy3+ composite materials. Narrow-width red emissions are achieved for Eu3+ and Sm3+ composite materials. In conclusion, the different conjugate groups of modified polysiloxanes led to diverse luminescent properties of complexed materials. The excellent emissions mean that the efficient coordination effect and intramoleenlar energy transfer process between polysiloxane groups and lanthanide ions took place within these molecular-based complexed materials.