Polyalkynylation Of The Carbonyl Monomers

To establish novel efficient polymerizations are crucially important to the development of polymer science.While alkynes are having rich chemical properties,there have been various functional polymers prepared synthesized from alkyne-based monomers.At present,polymerization based on alkyne is mainly concerned with the polyaddition and polycycloaddition,in which the triple bond would always be transferred to the double bond,such as the preparation of polyacetylenes and the click polymerizations of azide-alkyne,thiol-alkyne,amino-alkyne and hydroxyl-alkyne.These well-established polyadditions and polycycloaddtions do enrich the family of alkyne-based polymerization.However,in these mentioned alkyne-based polymerizations,alkynes always function as electrophilic unit.Moreover,alkynes also have nucleophilicity,which could be utilized to establishing the alkynylations toward polyalkynylations.In this thesis,the nucleophilicity of the terminal aromatic alkynes were utilized and novel polymerizations based on the alkynylation to carbonyl and its analogues were successfully established as listed below.Firstly,a potassium tert-butoxide（t-Bu OK）-promoted tandem polymerization of aromatic diynes and commercially available benzaldehyde,in which ethynyl groups were used as nucleophiles,was successfully developed.With optimized conditions,this polymerization could produce polymers with good solubility,well-defined structures,high-weight-averaged molecular weights（M_w,up to 76,000）,and yields up to 93%in as short as15 min at room temperature.Moreover,the resultant polymers show the interesting luminescent property,and some are aggregation-induced emission（AIE）-active.Secondly,we used the aromatic ketones,the analogues of the aromatic aldehydes,to develop a simple and efficient alkali-promoted polyalkynylation.The polymerization with the terminal alkyne monomers and the ketone monomers can proceed smoothly with potassium tert-butoxide（t-Bu OK）,and a series of polymers with high weight-average molecular wight and well-defined structure were obtained in good yields.the obtained polymers are similar to that of the previous part,which also show interesting luminescent phenomenon and aggregation-induced emission active.Subsequently,on the inspiration of the successful establishment of the polyalkynylations of aldehydes and ketones,we then developed a polyalkynylation of aromatic carboxylates.In the polymerization,the terminal aromatic alkynes proceed a process similar to the Claison ester condensation under the presence of potassium tert-butoxide（t-Bu OK）,which the alkynes undergo a nucleophilic addition to the aromatic carboxylic ester.By systematically optimizing the polymerization conditions,the polyalkynylation can proceed at room temperature for 2 hours to obtain polymers with high molecular weight in moderate yield.Using the efficient polyalkynylation to ketone,we successfully prepare a series of hyperbranch polymers with good solubility,good thermal stability and well-defined structure through an A_n+B₂ comonomer strategy.The resultant polymers are optical transparent in visible spectral region and possess high refractive indices,being promising to be used as advanced optical materials.Additionally,polymer with tetraphenylethene（TPE）moiety behave aggregation-induced emission（AIE）active,which is beneficial for developing its application.