Synthesis And Characterization Of Fluorinated Polymethacrylate Nanocomposites Emulsion And Nanocomposites Materials

Polyacrylate latex and nano-composites have widely applied in polymeric materials. Polyacrylate latex is an efficient environment-friendly modern material which has attracted more attention and research. The research is mainly to enhance the age-resistance property of polyacrylates, glass transition temperature and thermal stabilities and mechanicals. Fluorine-containing polyacrylates has good age-resistance property and self-cleaning effect. Nano-materials can enhance the physical and mechanical properties. On the other hand,the self-stratifying coating also had attuacted more attention and research at present. In this work,the fluorine containing core-shell nao-composite emulsion and nano-composites were prepared by in situ reaction,core-shell emulsion copolymerization and physical blend methods. The core-shell emulsions and nano-composites with good properties were obtained and were characterized. The main contents as follow:1. Fluorine/siloxane-containing core-shell emulsion polymerization:The fluorine/siloxane- containing core–shell composite latex was synthesized by emulsion polymerization technique through semi-continuous dropping method. The P（BA/Na AA） and Twain-80 as emulsifier, K₂S₂O₈ as initiator. Firstly, emulsion polymerization of siloxane and acrylate monomers as core, copolymers of 2, 2,2-Trifluoroethyl Methacrylate（TFEMA） and other acrylate monomers as shell. The latices and its films were characterized by using TG,TEM,FTIR,DMA and laser particle diameter analyzer. It is noted that the average particle size of latex is 400⁷00nm. The FTIR showed that siloxane and acrylate monomers had in the copolymer. Thermal decomposition performance was decreased and age and water resistance property was improved.2. Synthesis of fluorine-containing core-shell polyacrylate nano-composite emulsion which modified by polyhedral oligomeric silsesquioxanesFluorine-containing core-shell polyacrylate nano-composite emulsion was synthesized as above mentioned. The composite emulsion was modified by methylacryloypropyle polyhedral oligomeric silsesquioxanes（MAP-POSS） and vinyl-containing POSS（V-POSS）. The latexs and its films were characterized by FTIR,DMA,TGA,TEM,XRD,NMR and laser particle diameter analyzer. FTIR and TEM showed that POSS was polymerized in core-shell copolymer. Latex particle size is uniform and is 32.9³6.1nm. TGA shows that the thermal stability of the nanocomposite was enhanced with the increasing POSS content,and the initial decomposition temperature Tid increase 26 oC when it contains 9wt% MAP-POSS,and Tp increase 10 oC. However,added V-POSS with the same method,Tid and Tp enhance only 19 oC and 5 oC,respectively.3. Synthesis of core-shell polyacrylate nano-composite emulsion which modified by carbon nanotubes and graphene oxideFluorine-containing core-shell nano-composite polyacrylate latex was improved by adding CNTs and GO respectively. In the first step,CNTs（or GO）-containing core monomers was dispersive by supersonic blending method and polymerized,soon after,the shell monomers were dropped and polymerized. The latex gets a good stability. When nano-composite contain 0.1wt% CNTs,Tg increase 10 oC,Tid increase 14.2 oC. When CNTs-containing is 0.6wt%,tensile strength increase 20.3MPa,impact strength increase of 1.6 times,but the electric properties have not any more change.When grapheme oxide（GO） was added in nano-composite polyacrylate latex,the initial decomposition temperature Tid decreased abviously,with the adding of GO coutinusly,Tid increased slowly. with the adding of GO,Tp decreases,so that the impact strength will increase. The dielectric constant increases and dielectric loss angular tangent value decreases.4. Synthesis of fluorine-containing core-shell polyacrylate nano-composite emulsion which modified by in-situ generated SiO₂/Al₂O₃Fluorine-containing core-shell nano-composite polyacrylate latex was improved by in-situ generated nano-SiO₂/Al₂O₃ from tetraethyl orthosilicate and aluminium isopropoxide. The latices and its films were characterized by using FTIR,TG,DMA and laser particle diameter analyzer. The results showed that the diameter of latex decreases,the average size is 10-30 nm,with the increasing of nano particles the SiO₂ and Al₂O₃ amount. Tg of the nanocomposite decreases with increasing nano-SiO₂/Al₂O₃ content in 1%¹1wt%,it shows that nano-particles can enhance the toughness of polyacrylate polymer. The initial decomposition temperature Tid decreases,it explained that the nano-SiO₂/Al₂O₃ can catalyze the decomposition of the polar polyacrylate.5. Self-stratifying coatingIn this work,two kinds of self-stratifying coating were prepared. One is between fluorine-containing polyacrylate（PFMA） emulsion and polyacrylate（PMA） emulsion. The other one is between epoxy resin and fluorine-containing polyacrylate resin. In the first,the solubility parameters of FPMA and PMA were calculated, and the self-stratifying FPMA/PMA coating was prepared by the method of blending FPMA emulsion and PMA emulsion. The film of self-stratifying coatings was characterized by DMA,FTIR,laser particle diameter analyzer and the polarizing microscope. Polarizing microscope photos had demonstrated that the film has good self- stratifying results.In another work,the waterborne epoxy emulsion was prepared by phase inversion technique. Self-stratifying coating was prepared by the method of blending the waterborne epoxy emulsion and watherborne polyacrylate emulsion. Film was tested by polarizing microscope and FTIR. The results showed that self-stratifying films had formed for an appropriate thickness of film.