Preparation,characterization,and Inking Of Thermally Expanded Microcapsules For Printing Applications

Microcapsules refer to the use of monomers to generate water-insoluble polymers by changing the conditions,and the resulting polymers encapsulate solids,liquids,or gases in them to form tiny containers with a core-shell structure.There are many methods for their preparation,including suspension polymerization,interfacial polymerization,in situ polymerization,emulsion polymerization,etc.Currently,thermally expanded microcapsules are prepared by suspension polymerization in the literature.Although thermally expanded microcapsules have been widely used,there are great limitations in particle size,and the existing thermally expanded microcapsules are too large in size before expansion,resulting in many aspects of practical applications.In addition,the traditional thermally expanded microcapsules only have a single function of thermal expansion,which also greatly limits their application scope.Therefore,in this thesis,the following studies were conducted to address the above problems:(1)Thermally expanded microcapsules were prepared by suspension polymerization method,using hexane,which is non-toxic,non-corrosive,non-combustible and has little effect on the contents,stable and not easily decomposed,as the core material,and acrylonitrile,methyl methacrylate,and methyl acrylate,which have a good gas barrier and can improve the flexibility of the wall material,as the wall material.The experimental results show that the thermally expanded microcapsules prepared with the emulsifier sodium dodecyl sulfate,a homogenization speed of 800rpm and a homogenization time of 60min for the oil phase have a small particle size,good morphology,and expansion effect.(2)To solve the functional singularity of thermally expanded microcapsules,the surface of microcapsules was modified with conductive polymers to give them conductive properties.The conductive thermally expanded microcapsules with the optimal effect were selected among the modification concentrations of 0.5%,1.0%,1.5%,2.0%,and 2.5%.The experimental results showed that the temperature of thermally expanded microcapsules after modification decreased,i.e.,the thermal conductivity increased,while the analysis of their morphology and spectra confirmed that the conductive polymers were indeed successfully modified on the surface of microcapsules,and the expansion effect of microcapsules was slightly limited.(3)The obtained thermally expanded microcapsules were subjected to inking and printing applications.The obtained optimized microcapsules were configured with printing stock,color paste,defoamer,leveling agent,etc.to form physical foaming ink and printed on cardboard,cotton,non-woven and other substrates by screen printing,and the foaming height,sound insulation performance,and waterproof performance were tested in comparison with simple substrates and ordinary ink.The experimental results show that the physical foaming ink formulated by thermally expanded microcapsules has better foaming height,sound insulation performance,and waterproof performance than the simple substrate and ordinary ink...