Recently, great effort has been devoted to prepare various reinforce fillers to improve polymer performances, but ignoring the importance of raw polymer powders which are indispensable parts of hot-pressed polymer composites. Herein, we engineer raw polyimide (PI) powders with the assistance of polydopamine (PDA) in aqueous solutions. After the modification, polymer powders change from hydrophobic to hydrophilic, which makes it is possible to further modification of polymer powders in liquid phase. During the curing process of modified polymer powders, the partial dehydration of the catechol groups and crosslinking of PDA via C–O–C bonds are confirmed. Based on the features of PDA, a non-destructive mixing method is utilized to realize homogeneous dispersion of multi-walled carbon nanotubes (MWCNTs) in polymer matrix. In comparison with ball milling method, this way can preserve the integrated innate structure of MWCNTs effectively. Besides, by taking full advantage of the reducing and metal-coordination capability of PDA, Cu2+ is successfully loaded onto the surfaces of polymer powders. The related characterizations demonstrate that Cu2+ in situ converts to metallic copper rather than copper oxide during the hot pressing process. The tribological properties of corresponding polymer composites are also studied. These results indicate that modifying polymer powders with PDA is multi-profit and presents practical application prospect.

Liangfei WU;Zhaozhu ZHANG;Mingming YANG;Junya YUAN;Peilong LI;Zujun CHEN;Xuehu MEN

State Key Laboratory of Solid Lubrication,Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou 730000,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;School of Physical Science and Technology,Lanzhou University,Lanzhou 730000,China

摩擦（英文）

[1]Liangfei WU;Zhaozhu ZHANG;Mingming YANG;Junya YUAN;Peilong LI;Zujun CHEN;Xuehu MEN-.Surface modification of YS-20 with polydopamine for improving the tribological properties of polyimide composites)[J].摩擦（英文）,2022(03):411-421

Surface,modification,YS,polydopamine,improving,tribological,properties,polyimide,composites,Recently,great,effort,been,devoted,prepare,various,reinforce,fillers,improve,polymer,performances,but,ignoring,importance,raw,powders,which,indispensable,parts,hot,pressed,Herein,we,engineer,assistance,PDA,aqueous,solutions,After,change,from,hydrophobic,hydrophilic,makes,possible,further,liquid,phase,During,curing,process,modified,partial,dehydration,catechol,groups,crosslinking,via,bonds,confirmed,Based,features,destructive,mixing,method,utilized,realize,homogeneous,dispersion,multi,walled,carbon,nanotubes,MWCNTs,matrix,In,comparison,ball,milling,this,way,can,preserve,integrated,innate,structure,effectively,Besides,by,taking,advantage,reducing,coordination,capability,Cu2+,successfully,loaded,onto,surfaces,related,characterizations,demonstrate,that,situ,converts,metallic,copper,rather,than,oxide,during,pressing,corresponding,also,studied,These,results,indicate,modifying,profit,presents,practical,application,prospect

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