Synthesis And Characterization Of Polymers Containing Tpe Moieties Via ADMET Polymerization

Traditional fluorescent materials have aggregation-caused quenching phenomenon due to ?-? stacking interaction.The fluorescence of this kind of materials in the solution state is strong,but the fluorescence is quenched in the solid state or in the aggregation state.In contrast,the aggregation-induced emission phenomenon found in 2001 is contrary to the limitation of traditional thinking,which can improve the development of fluorescent materials.Conjugated polymers with aggregation-induced emission property have more advantages in practical applications,and their structure-property relationship is also very important.Acyclic diene metathesis polymerization is an excellent method to study structure-property relationship of polymers in recent years,and has been widely used in the preparation of various new functional polymers.It belongs to condensation polymerization mechanism.In this dissertation,tetraphenylethylene with diene was synthesized.By acyclic diene metathesis polymerization,a series of conjugated and non-conjugated polymers containing tetraphenylethylene moieties with aggregation-induced emission property were prepared for the first time by acyclic diene metathesis polymerization,and they also exhibit aggregation enhanced emission effect.By the appropriate monomer design and synthesis strategy,structural control of the polymer is achieved.We analysed the influence of long length of the conjugated chain,changes in the structure of the polymer backbone,and insertion of non-conjugated segments on the conjugatin and optical and thermal properties of polymers.For three conjugated polymers PDBVE-2.1k,PDBVE-3.0k,PDBVE-6.3k with diffrent molecular weight,we found that the increased length of the conjugated chain allows the red shift of the absorption and emission wavelengths of the materials.Conjugated monomer DBVE and non-conjugated monomer hexadiene was copolymerized to obtain the non-conjugated polymers.The non-conjugated carbon chain allows the absorption and the emission wavelength to blue shift.Some monomers with alkoxy chain segments were prepared,and monomer DPOE could not be polymerized due to negative neighboring group effect.But the alkoxy chain segments with different lengths have no obvious effect on the optical property of polymers PDBOE and PDHOE.And heat resistant property of polymers was studied.We found these polymers containing tetraphenylethylene moieties have a large number of benzene rings in the structure,so they have large rigidity and good thermal stability.The introduction of flexible carbon segments in the chain structure can reduce the molecular rigidity and lower the decomposition temperature,which may be helpful to improve the processing performance of materials.