One-pot Prepare Of Polysulfonate By A Cascading Sulfur(Ⅵ) Fluorine Exchange Reaction And Cyanosilylation Of Aldehyde

Polysulfonate have been shown to have excellent mechanical properties and high chemical stability,which makes them potential engineering polymer materials.It possesses some distinguishing features such as high strength,high heat and corrosion resistance,excellent anti-hydrolysis and anti-ammonia stability,which combine the advantages of polycarbonate and polysulfone.So it is especially suitable for machinery,national defense,electronics technology and other fields.In 2014,Prof.Sharpless proposed sulfur（VI）fluorine exchange（Su FEx）reaction as a new generation of click chemistry,which inspired a new wave of research for the synthesis of polysulfonate.In the following years,some remarkable results have been reported on the synthesis of polysulfonate,but so far,the structural variety of polysulfonate is still very limited.Previously,cyanosilylation reaction of aldehyde,which is one of the important reactions to obtain optically active cyanohydrin,has been studied in our laboratory in detail and is of great research value in the field of chiral synthesis.We are keenly aware that the reaction could be applied to the synthesis of polysulfonate.Based on this idea,a series of studies were conducted to synthesize new polysulfonate by a one-pot method using aldehyde as the starting material by cascade cyanosilylation reaction with Su FEx reaction.Furthermore,utilizing the CN group on the branched chain,the post modification of the polymer was studied.The specific works are as follows:（1）Six bis-aldehyde compounds were prepared and the silyl ether compounds MSi1-6were synthesized whereafter throught the reaction of trimethylcyanosilane（TMSCN）and bis-aldehyde compounds.The reaction conditions were investigated in detail.Sulfonyl fluoride compound MF was prepared from an inexpensive sulfonyl chloride based compound by a biphasic halogen exchange reaction.The structures of the compounds were characterized using¹H NMR,¹³C NMR and¹⁹F NMR,and the thermal stability of monomers was characterized using TGA.（2）The prepared silyl ethers MSi1-6 were subjected to Su FEx reaction with sulfonyl fluoride MF in sequence,and the optimal reaction conditions of the polymerization reaction were investigated in detail.¹H NMR,¹⁹F NMR,FT-IR and XRD characterized the structures of the polymers.The thermal properties of the polymers were characterized by TGA and DSC,and the Young’s modulus of the polymers was fitted by AFM to characterize the mechanical properties.Three bulk macromolecules Post1-3 were prepared by post-polymerization modification of polymer P4,and the changes of thermal properties before and after modification were observed by TGA.The results of the study showed that:The cyanosilylation reaction of aldehyde could be quantitatively converted in solvent-and catalysts-free conditions,which is the foundation of the"one-pot"synthesis of polysulfonate via Su FEx reaction.The entire process was convenient and economical.P1-6 all exhibited excellent thermal stability and high Young’s modulus,and the modified product Post1-3 showed further improvement in thermal properties.