Research On The Chemical Preparation And Properties Of The New Conjugated Conducting Polymers

Recently,donor-acceptor approach was commonly applied for reducing the band gap and avoiding solubility problems.In this paper,we highlight the synthesis of several novel donor-acceptor type polymers.There eight kinds of new conjugated conducting polymers,then,a series of characterizations were carried out by cyclic voltammetry?CV?,density functional theory?DFT?,UV-vis-NIR spectroscopy,kinetics method,colorimetry and thermal gravimetric analysis,etc.According to the obtained datas,we can analyze the structural units have impact on the nature of the copolymers.Chosen benzotriazole derivative and benzothiadiazole as acceptors,thiophene and its derivatives as donors,P?TBT-F-TBTh?and P?TBT-TBTh?were synthesized by Stille coupling reaction.The result of characterizations of the polymer shows that the colors of the polymers were faded,the brightness was increased,when an external voltage was applying.The optical band gap of P?TBT-F-TBTh?was 1.59 eV,the value of P?TBT-TBTh?was 1.50 eV.Applied voltage on P?TBT-TBTh?,the optical contrast ratio was 34.1%,the response time was 1.3 s,the coloration efficiency was 128.9 cm²C^-1 at 610 nm;while at 1550 nm,the optical contrast was 76.7%,the response time was 1.1 s,coloration efficiency was 258.5 cm²C^-1.Regard benzothiadiazole derivatives as the same receptor,P?ThC-OBT?,P?ThF-OBT?,P?DOTC-OBT?and P?DOTF-OBT?was successfully synthesized by Suzuki coupling reaction.Their characterization shows that when the applied voltage was applied,P?ThC-OBT?and P?ThF-OBT?were from A pale red to gray-green,P?DOTC-OBT?and P?DOTF-OBT?were from golden yellow to dark green;what's more,optical bandgap of these fourth polymers was followed by 1.87 eV,1.93 eV,2.16 eV,2.07 eV.Besides,four substances all have larger optical contrast,shorter response time,higher coloration efficiency in the near infrared.P₁includedbithiophene-carbazol–benzothiadiazoleunitsandP₂included bithiophene-fluorene-benzothiadiazole units were synthesized by Suzuki coupling reaction.The two new copolymers were polymerization from three different monomers.The optical band gap of P₁ and P₂ were 1.96 e V and 1.95 eV separately through optical characterization.P₁ and P₂ were from carmine to pale green under the applied voltage.Dynamic performance parameters were obtained through characterization.For example,the optical contrast ratio of P₁ and P₂ were 33.0%and 26.0%,the response times were 1.6 s and 3.5 s,the coloration efficiency were 78.8 cm²C^-1 and 87.9 cm²C^-1 in the visible region;the optical contrast ratio of P₁ and P₂ were 50.9%and 51.4%,the response times were 1.5 s and 2.8 s,the coloration efficiency were 243.4 cm²C^-1 and 230.2 cm²C^-1 in the near infrared region.In terms of TGA,the degradation temperature of the two polymers were 300?.