Highly Efficient Activated Alkyne-based Polymerizations And Applications Of The Products

Developing highly efficient polymerizations under mild conditions is always the pursuit for synthetic polymer chemistry.By activating alkynes with electron-withdrawing groups,their reactivity can be greatly improved,and thus suitable for polymerizations under mild conditions.At the same time,polymers with versatile properties can be obtained from the polymerizations of activated alkynes.The research about efficient non-catalysis polymerizations between activated alkynes and amines at room temperature has drawn much attention,but still needs to be further explored.In this thesis,highly efficient bi-or multi-component polymerizations based on activated alkynes and amines are established,and the properties of the products are also investigated.The creative results are as follows:First,after simplification of the synthetic procedures,disubstituted aroylacetylenes have been used for developing amino-alkyne click polymerizations.Different from other reported activated alkynes,aroylacetylenes possess high reactivity,good stability,as well as low biotoxicity.The click polymerization of aroylacetylenes and amines occurred efficiently at room temperature without any catalysis,and a series of anti-Markovian poly(?-enamine)s with high molecular weight were obtained in high yields(up to 99%).At the same time,this polymerization showed excellent stereoselectivity.Unity E-configuration polymers can be prepared in the polymerizations with secondary amines,whereas,Z-isomer-containing polymers were generated from the polymerizations of primary amines and aroylacetylenes.The reactivity and selectivity of the reactions between different amines and activated alkynes have also been investigated by theoretical calculations,which will guide the development of click polymerizations of other activated alkynes and amines.The generated poly(?-enamine)s are thermally stable,but could be readily degraded in the presence of monosubstituted primary or secondary amines,for their containing of the dynamic ?-enamine groups.Moreover,under the synergism of aniline and acid,the degradation reactions can take place precisely in aqueous solution,and low mass molecules with definite structures could be obtained.In addition,the emissive unit containing polymers showed unique response toward p H values.Second,the produced poly(?-aminoacrylate)s even without any aromatic group were found to show enhanced emission when treated with acid.After the treatment of acid,?-aminoacrylate groups can be cyclized into unconventional luminescent dihydropyridine derivatives.The response and time course of poly(?-aminoacrylate)s toward acids of different kinds and concentrations were also studied.In addition,the acid induced fluorescence enhancement of poly(?-aminoacrylate)s was also used for making acid responsive anticounterfeiting fluorescent patterns.Finally,by subtly taking use of the carbonyl or ester group activated internal alkynes,efficient three-component polymerizations of activated alkynes,amines and carbon disulfide were established under room temperature without any catalysis.Poly(vinyl-dithiocarbamate)s with satisfactory molecular weights and good regioselectivity were produced in the yields up to 97%.This kind of polymers were easily pyrolyzed below 250 ?.At the same time,they showed unique nonlinear optical properties with refractive indices as high as 1.75 and good light transmittance.This work provides an efficient and low-cost strategy to synthesize polymers with high refractive index from carbon disulfide.