Evolution And Regulation Of Microphase Structure During Baking Film Formation Of Composite Latex

At presence of functional particles, the film formation of composite latex on fabric surface is a conventional process in functional finishing of textiles. However, the dispersion and bonding strength of functional particles in traditional finishing latex film were always poor, attributed to the latex blend form. In recent 20 years, based on the great development of in-situ polymerization technology, a series of composite particles with controllable structures have been successfully prepared. The application of these composites latexes onto functional finishing has been proven to be one of the most promising ways to solve the above problems. However, the structure formation mechanism of the composite latex film, especially the dispersion and aggregation behave of the functional particles during film-forming process is still lack of systematic understanding.In this study, the hydrophobic organic pigment copper phthalocyanine blue(PB) hydrophilic and silica(SiO2) were took as the representation functional particles, and the most common polyacrylate(PA) the representative adhesive. A series of blending and composite structure of the composite latex are successfully prepared via physical blending, in-situ micro-suspension polymerization, in-situ emulsion polymerization and in-situ miniemulsion polymerization. Then these blended and composite latexes were used to baking film experiment. The dispersion states of functional particles in latex and in latex film were charactered by DLS, 3D-POM, TEM, AFM,FE-SEM, XPS, spectrophotometer, and rubbing fastness experiment. After that, the dispersion and dispersion stability of functional particles in adhesive film were systematically associated with the morphology of composite latexes, in order to explore the structure formation mechanism of the different composite film.It was found that, attributing to the lack of effective combination with adhesive latex, pigment particles in blended organic pigment latex didn’t move with latex polymer chain during film-forming process. But composite system of organic pigment composite latex, pigment particles have been efficiently wrapped in binder colloidal particles.So pigment particles in blended organic pigment latex moved with latex polymer chain during film-forming process. Eventually can be efficiently distributed in the latex film.It makes the composite pigment latex film better color depth, color fastness and color uniformity.With precisely observing the film-forming process,the pigments area change line of the organic pigment composite latex show S –shaped during in the process of baking film.There are three characteristic value including sticky flow initial temperature Tl, spreading equilibrium temperature Tk and balanced growth area of the growth rate of Ks, which can be used to evaluate organic pigment composite colloidal particles sticking out.In the process of latex paint film, reducing the glass transition temperature Tg, enhancing pigment content, reducing the rate of gel, improving heating rate can increase pigment particles dispersity in composite latex film.For nanoscale latex film, during the film-forming process of the emulsion polymerization of PA/SiO2 composite latexs, SiO2 particle clusters don’t move with PA chain moving,which eventually lead to SiO2 particle clusters exist on the surface of the composite latex film.The disperse state of.functional particles belong to a thermodynamic steady state. During the film-forming process of the miniemulsion polymerization of PA/SiO2 composite latexs, SiO2 particles move with PA chain moving,which eventually lead to SiO2 particle uniformly disperse on the surface of the composite latex film. Compared with the traditional blending composite latex film, the function particles SiO2 are effectively encapsulated in the inner of latex particlese,which lead to a small size cluste-like structure or a primary particle structure achieve.Finally fuctional particles great aggregation is avoided in the process of high temperature baking film-forming.Form above two micro-nano baking composite latex film,functional particles can realize uniform stability of dispersion in the latex film by effectively encapsulated in the inner of composite latex.In this basic research, the law of function particles’ dispersion and aggregation in the film-forming process was systemically studied, and the structure formation mechanism of the honeycomb and cluster-like composite latexes film were revealed. The results are conducive to guide the design, production and application of composite latex for the function finishing of textiles.