Aliphatic polysulfones exhibit many excellent properties,such as high transparency,high refractive index,and low hygroscopicity.Currently,polymers are capable to be used as photoresistors,adhesives,and thermally degradable materials.Despite the potential advantages of aliphatic polysulfones,there are still some limitations to meeting the advancing industrial demands.Therefore,further modifications in polysulfones are highly required to improve their properties and expand the range of applications.Silicone polymers,with unique properties such as low and high-temperature resistance,low toxicity,and physiological inertness,are widely used in aerospace,medical and chemical engineering,and other fields.The design of novel poly(sulfone siloxane)s is achieved by combining the sulfone groups and siloxane units,and the resulted polymers are expected to perform excellent advantage of both the two advanced materials.However,the study of the reported poly(sulfone siloxane)s was preliminary.The development of new preparation methods and structure designing of functional poly(sulfone siloxane)s are quite significant.In this thesis,aliphatic poly(sulfone siloxane)s are selected as the research target.A series of novel poly(sulfone siloxane)s and elastomers were obtained based on ring-opening polymerization and metal-ligand coordination bonding.The main contents are as follows:1.A series of novel poly(sulfone siloxane)homopolymers were prepared by sulfone-containing cyclosiloxane monomers with different structures via anionic ring-opening polymerization.The preparation method was optimized,and the structures of resulted polymers were characterized.Besides,the properties of the products were investigated,and the factors in the preparation and properties of polymers were studied.The experimental results showed that the molecular weight of polymers was controlled by the feed ratios of cyclic monomers to catalyst.Due to the incorporation of siloxane units,the resulted poly(sulfone siloxane)s exhibited many advantages compared to the pure aliphatic polysulfones,such as good solubility,low glass transition temperatures,and relatively high degradation temperatures exceeding 310℃.Additionally,the obtained poly(sulfone siloxane)s showed good recyclability,which could be depolymerized into the initial cyclic monomers with the high conversion of 86%in the presence of KHSO4.2.The carboxyl-functionalized poly(sulfone siloxane)s were synthesized by the vinyl-containing poly(sulfone siloxane)s via thiol-ene reaction.Then a series of elastomers with good dielectric properties were obtained by introducing the iron ions into the carboxyl-functionalized poly(sulfone siloxane)s.Owing to fact that the dipole polarization of sulfone units and carboxyl groups and the interfacial polarization of the clusters formed by the aggregation of iron ions and carboxyl groups,the resulted polymers revealed good dielectric properties with a high dielectric constant of 12.8.Additionally,the influence of the structures of poly(sulfone siloxane)s on the glass transition temperatures,thermal stability and mechanical properties were investigated.The elastomers could be recycled after simple treatment. |