Preparation And Characterization Of Carbon Nanotubes Conductive Inks Based On Waterborne Polyurethane

Due to the special physical and chemical properties,conductive inks have been playing a key role in electronic printing,advanced micro-nano manufacturing and biomedical engineering.The main componments of these inks,namely binders and conductive pigments,decide the performance and application of them.This dissertation focuses on the preparation and characterization of waterborne polyurethane(WPU),conductive pigments based on carbon nanotubes(CNTs)and environment-friendly conductive inks.In addition,the printing process and applications of conductive inks are studied briefly.On one hand,in preparing binders based on waterborne polyurethane,we pay attention on the polyurethane properties meeting the requirements of printing inks,such as good stability,low cost,suitable solid content and viscosity,high adhesion and fast drying.In order to supply the experimental foundation for application of WPU in environment-friendly conductive inks,the correlation among raw materials,bulk structure of polymer chains,micro morphology and performance are investigated.On the other hand,in preparing conductive pigments,we focus on the dispersion of CNTs in polymers to explore the preparation processes of high stability and cinductivity,homogenous conductive pigments.The key problems,including un-stability and aggregation of CNTs,are studied in detail according to the CNTs surface kinetic decoration and thermodynamics decoration methods.A simple synthetic method for low cost WPU has been developed based on waste PET as raw material.Waste PET had been degraded to obtain chemical active oligomer(GOP).And then,GOP was used to synthesize WPU dispersion.A system for recycling waste PET with high efficiency has been built.A convenient prediction model based on grey relation theory for correlation between raw materials and performance of WPU has been developed.The chemical process which is hard to control is ignored in this prediction model.It supplies theoretical basis for adjusting WPU dispersion performance.A facile synthetic procedure for preparation of novel WPU with good properties has been developed based on water in different forms and temperatures.In situ water generated process(WGP)has been built including physical and chemical water generation processes.The emulsification,chain extending and dispersion processes of polyurethane prepolymer have been adjusted by water.The WPU obtained via WGP by physical water generation method has good stability,homogenous nanoparticles,good adhesion and mechanical properties,and suitable surface wettability.An effective method for decorating CNTs surface to improve its dispersion property has been developed through kinetic decoration and thermodynamics decoration methods.Good dispersion and high conductivity CNTs based conductive pigments are prepared according to these processes.Different WPU dispersions and CNTs based nanocomposites were mixed via facile process to prepare environment-friendly conductive inks.Moreover,the applications in direct-writing inks and screen printing inks have been investigated.The correlation between printability and morphology of inks has been studied to solve the application problems of conductive inks in flexible and electronic printing industry.