Preparation And Performance Of Waterborne Polyacrylate Resin Based Flexible Finishing Materials

As a new type of building finishing material,flexible finishing material(soft porcelain)has the advantages of good flexibility,light weight,multi-color and shape,energy saving and environmental protection,and has become one of the focuses of research and development in the field of green building materials in the world.Soft porcelain is made of waterborne resin,industrial tailings slag,construction discard,stone powder,glass fiber and other materials,through high-speed homogeneous dispersion,curve drying and shaping processes,of which waterborne resin is the key matrix material for soft porcelain molding.However,at this stage,most of the waterborne resins in the industrial production of soft porcelain use of physical blended commercial waterborne acrylic resins with low glass transition temperature and high glass transition temperature,which have defects such as poor weather resistance and low cross-linking with inorganic fillers,resulting in easy cracking,which seriously restricts its promotion and application.In this paper,epoxy-based waterborne acrylic resin was synthesized by seed emulsion polymerization,and soft porcelain was prepared by using this as a molding material.The regulation of the weather resistance and mechanical properties of soft porcelain by crosslinking agent types and crosslinking methods was studied,and high-performance soft porcelain was prepared.Epoxy-based waterborne acrylic resin was synthesized by seed emulsion,and cross-linked soft porcelain was prepared by cyclo-opening crosslinking of epoxy and amino group and hydrolysis crosslinking of silane coupling agent by glycidyl methacrylate(GMA)and 3-(trimethoxysilyl)propyl methacrylate(KH570)as cross-linked functional monomers,and Hexion Epikure 8538-Y-68 as amine curing agent.The effects of GMA,KH570,glass transition temperature and other factors on the weather resistance and mechanical properties of waterborne acrylic resin coating film and soft porcelain were systematically investigated.The regulation of cross-linked soft porcelain structure and its thermal stability,crystallinity and surface morphology were studied by thermogravimetric(TGA),X-ray diffraction(XRD),scanning electron microscopy(SEM)and atomic force microscopy(AFM).Through the optimization process,the water absorption rate of the prepared cross-linked soft porcelain was reduced from 7.8% to 2.8%,the elongation at break increased from 0.54% to 1.41%,the tensile strength increased from 0.51 MPa to 1.87 MPa,and the number of freeze-thaw cycles was increased from 30 to 75.In order to further improve the weather resistance and mechanical properties of soft porcelain,based on the epoxy waterborne acrylic resin in Chapter 3,waterborne polyurethane resin(PU)and polypropylene glycol diglycidyl ether(PPGDGE)are used as the weather resistance and mechanical strength control materials of soft porcelain,and after high temperature baking and deamination,chemical cross-linking and blending with polycarbide diimide or nitropropidine are carried out to prepare cross-linked soft porcelain with excellent weather resistance and mechanical properties.The addition amount of PU and PPGDGE,the amount and type of curing agent,and the effects on the weather resistance and mechanical strength of coated film and soft porcelain were systematically investigated.The chemical crosslinking process of coating films was studied by gel permeation chromatography(GPC),nuclear magnetic resonance(NMR)and infrared(FTIR).TGA,XRD and SEM were used to explore the relationship between the structure of cross-linked soft porcelain and its thermal stability,crystallinity and surface morphology.Through the optimization process,the elongation at break,tensile strength and freeze-thaw cycle times of the cross-linked soft porcelain were 1.25%,16.02 MPa and 98 times,respectively.