Preparation And Applications Of Fluorine-containing Maleimide-based Functional Materials

Smart responsive materials have urgent requirements in information storage,anti-counterfeiting,sensor,color imaging,biomedicine and so on.Among them,the construction of erasable information system based on stimulus-responsive materials is an effective strategy to solve the traditional resource waste.At present,many intelligent responsive inorganic,organic,organic/inorganic composite systems have been successfully developed for erasable information storage,however,most of the above systems have limitations such as poor film forming,cumbersome preparation steps,low information resolution/short readable time,et al.In recent years,stimulation-responsive polymer systems containing stable five-membered ring maleimide structural units have the advantages of simple synthesis,easy chain structure regulation,multiple stimulus response,etc.,and become the ideal materials for building intelligent information storage materials system.In this paper,a series of information storage systems are constructed based on maleimide.（1）Maleimide（RMI）monomer containing different groups was prepared,and the monomer was used to polymerized with MDAA to obtain the oligomer.Moreover,due to the different electron-absorbing ability of R group in RMI structure,the oligomer color gradually deepened with the enhancement of electron-absorbing ability of maleimide.Under the stimulation of TFA/Et₃N,the oligomer constantly changes the structure of enolate and enol or ketone,leading to the alternating cycle of the color.The reversible erasable coating is prepared by mixing the oligomer and PMMA through spin coating.The oligomer P（p-TFMPh MI-co-MDAA）coating containing fluorine-maleimide has the highest resolution and clear color compared with the coating without fluorine-maleimide.Moreover,the coating also shows the characteristics of fast stimulus response,high information resolution,excellent storage stability and cycling stability.（2）RMI was copolymerized with vinyl carbazole（NVC）to obtain polymer with higher molecular weight,which solved the disadvantage of oligomer in film formation.The chromogenic mechanism of polymer is the protonation of NVC,and polymer in liquid/solid phases are showed excellent irritative responsiveness.According to different R group,the chromogenic time and color is different.P（CHMI-co-NVC）shows good responsiveness and solubility compared with the copolymers containing phenyl maleimide.The modified paper under the stimulus of TFA and triethylamine reveals quick responsiveness and circularity and higher resolution.Due to the different R group,the copolymer under the TFA stimulus shows different color,which can be used as a pigment dyeing for the paper.（3）A maleimide monomer containing azobenzene with multiple stimulus response was prepared and used for solution polymerization with TFEMA to explore the polymer structure and molecular weight.The discoloration mechanism of polymer under TFA stimulation is due to the five-member heterocyclic ring of MAB weakening the acidity of azobenzene,protonation rapidly occurred under TFA stimulation,and deprotonation rapidly occurred after Et₃N stimulation to restore the original color.The copolymer is successfully adhered to the fabric surface by a simple dip-coating method,and the modified fabric has excellent hydrophobicity,mechanical stability,acid and alkali resistance and self-cleaning,and can withstand harsh conditions.The fabric also shows excellent acid/base discoloration properties.The porous fabric structure and the copolymer’s uniform adherence to the fabric surface enable TFA to rapidly contact the copolymer to protonate and complete the color change.As a high-performance and sustainable information storage medium,a variety of fine pattern information can be repeated on fabric surfaces with rapid TFA printing and Et₃N erasure.In addition,a visual HF sensor was constructed using the modified fabric to detect HF leakage problems in industrial production with a detection limit of 2.7807 mmol/L,which has a good application prospect.（4）A hydrogel containing maleic anhydride,acrylamide and vinyl carbazole was prepared to study the interface factors on the stimulus response.Firstly,hydrogels with network structure were obtained by polymerization of maleic anhydride,acrylamide and NVC.The mechanical properties,self-healing and morphology of hydrogels were studied.And the thermal stability of gel polymers was analyzed.The effect of different p H aqueous solution and different strength of acid on the response of hydrogel stimulation was studied.The gel was used to construct the stimulus response system,and the interface contact directly affected the stimulus response of organic polymers.