Synthesis Of Functional Polymers By Metal-free Polymerizations Based On Internal Alkynes

Development of new polymerization reactions for synthesis of new functional polymers is of academic interest and technological value.The polymerizations based on alkynes have attracted much attention in recent years.However,the internal alkyne-based polymerizations are rarely reported.In this thesis,metal-free internal alkyne-azide and activated internal alkyne-thiol polymerization reactions were developed,and a series of functional polymers were prepared.The polymerization of azide and silylated internal alkynes was firstly explored.The optimal reaction conditions was determined through investigating the effect of reaction temperature,time and solvent on the yields,molecular weights and molecular weight distributions of the obtained polymers.Four tetraphenylethene(TPE)-containing poly(trimethylsilyltriazole)s(PSTAs)with satisfactory molecular weights was then synthesized by the polymerization.The polymers possess good solubility in organic solvents and high thermal stability.The PSTAs are non-emissive in dilute solution,but become highly emissive in aggregated state,exhibiting aggregation-induced emission(AIE)features.The aggregates of the polymers can be used as fluorescent sensors to detect polynitroaromatic explosive.Moreover,the poly(triazolium)s synthesized by the reaction of PSTAs and methyl iodide are soluble in water,and can be employed for live-cell imaging applications.The polymerization of thiol and butynoate was explored.We investigated the effect of solvents,temperature,time,and monomer concentration on the solubility,yields,molecular weights and molecular weight distributions of the polymers,and obtained the optimal reaction conditions.A metal-free polymerization of thiol and activated internal alkynes was developed.We prepared six poly(?-thioacrylate)s(PTAs)with high molecular weights.high region-and stereoregularities.Thanks to their contained aromatic rings,ester groups and sulphur atoms,the PTAs show high refractive indices.The TPE-containing PTAs display AIE characteristics.Their nanoaggregates can be utilized as chemosensors for sensitive detection of explosive.