Studies On Synthesis And Electrochromism Application Of Novel Optoelectronic Polymer Poly(Aryl Amino Ketone)s And Poly(Aryl Amino Sulfone)s

As mankind has entered the"electric age",the use of electricity has become more and more widespread.Electrochromic?EC?materials as one kind of electrical stimuli materials,their absorption and emission of light and heat can be regulated by electrical signals.EC materials are widely used in applications such as smart windows,antiglare rear-view mirrors and protective optics glass in view of their reversible and variable light transmittance or reflection.At present,the commercialized EC materials are mainly inorganic materials and organic small molecules,but the high processing costs limited their market prospect.High-performance polymers allow the fabrication of flexible,lightweight and colorful EC devices by low-cost and large-area processing methods,and have therefore drawn much attention.So,it is significant to design and synthesize a kind of high-performance polymers with excellent long-term cycling stability,low onset potential,fast switching time,high contrast and high coloration efficiency.According to the ideas for D-A structures and EC polyamide and polyimide,in this paper,we designed novel poly?aryl amino ketone?s?PAAKs?and poly?aryl amino sulfone?s?PAASs?with directly connected TPA and ketone/sulfone moieties as the repeating unit and probed the influence of the D-A structure change on photoelectric property.There were four mainly parts of our research work as followed:First,we improved the polymerization technology of nucleophilic substitution polymerization for PAAK and PAAS.In this process we summarize the optimal conditions for polymerization reaction by comparing different reaction conditions.This change increased the polymer molecular weights considerably.High molecular weight is beneficial to evaluate the intrinsic properties of polymers and to apply further processing.The cost of this reaction is relatively low.Only suitable amino monomers need to be prepared and they could directly polymerize with 4,4?-difluorophenyl methanone/4-fluorophenylsulfone.In the future industrial process,PAAS and PAAK could be produce with the same production conditions of PAEK and PAES,which has great development potential.Second,we designed a series of poly?aryl amino ketone?s?PAAKs?with directly connected TPA and ketone moieties as the repeating unit.For easy comparison,these polymers were separated into two groups:Group PAAK-TPA and Group PAAK-TPACz/TPPA.The polymers of Group PAAK-TPA were namely those with five TPA donors featuring different electron-withdrawing unconjugated substituents[hydrogen?PAAK-TPA-H?,methyl?PAAK-TPA-Me?,tertiary butyl?PAAK-TPA-^tBu?,and methoxyl?PAAK-TPA-OMe?].And Group PAAK-TPACz/TPPA polymers were carbazole?Cz?-based and tetraphenyl-p-phenylenediamine?TPPA?-based structures with elongated conjugation length[bis?tert-butyl?-carbazole?PAAK-TPACz-^tBu?,bis?methoxy?-carbazole?PAAK-TPACz-OMe?,bis?tert-butyl?tetraphenyl-p-phenylenediamine?PAAK-TPPA-^tBu?and N1,N1-bis?methoxy?tetraphenyl-p-phenylenediamine?PAAK-TPPA-OMe?].The results showed that all the PAAKs exhibited EC properties.Among these polymers,PAAK-TPA-H exhibited fast response speed?both coloring and bleaching process low than 1 s?;PAAK-TPPA-OMe exhibited rare low driving potential?0.50 V?and long-term cycling stability in near infrared region?over 2,400 cycles?;PAAK-TPACz-^tBu exhibited the highest coloration efficiency(907 cm² C^-1 at 730 nm).Unfortunately,the residual process solvent lead to excessive treatment temperature reduced the EC properties of PAAKs,which need further improvement.Third,based on the experience of the PAAKs,we designed novel poly?aryl amino sulfone?s?PAASs?with directly connected TPA and sulfone moieties as the repeating unit.Compared with PAAKs,the EC performance improvement of PAASs is huge.The best-performing polymer,PAAS-TPPA-OMe,exhibited a rare low onset potential?0.26V?,fast response speed?6.0/4.3 s for the EC process?,long-term cycling stability?over3,900 cycles?,and high coloration efficiency(1131 cm² C^-1at 928 nm).Moreover,we revealed new rules to design and develop D-A structure polymers with high EC cycling stability:?1?the electron donating and withdrawing abilities of donor and acceptor should be balanced during the electrochemical cycle process,and this balance can be measured by the ratio of J_red/J_ox;?2?the donor-acceptor structure should benefit to generate lower E_onset to avoid other electrochemical side-reactions.These rules could also be used to explain related phenomena in other published work of D-A type high-performance polymers.We suggested this conclusion possibly holds for all other D-A-type electrochromic materials.In a word,the polymer PAAK and PAAS were a new kind of high-performance polymers.They provide a new molecular design selection for optoelectronic polymer.