| EP needs to be dissolved by organic solvents during application,which causes serious environmental pollution problems.Therefore,research and development of green,environmental and water-soluble EP has become a hot research in various fields.Introducing a hydrophilic flexible PEG segment into an EP structure,which achieves the purpose of water hydration while improving the Brittle,poor peeling resistance,poor impact resistance of the epoxy resin film.However,at the same time,the hardness and wear resistance are lowered,and the EP-PEG needs to be modified again..NCC has high hardness and high strength,which can compensate for the lack of hardness and wear resistance of EP-PEG.Therefore,the PEG segment was grafted into the EP structure by chemical modification method.Secondly,the NCC blending and copolymerization were used to modify the EP-PEG to synthesize the nanocomposite.The study draws the following conclusions:(1)The synthesis process of EP-PEG is:time is 6h,temperature is 90?,the content of BF3 is 0.8%,select PEG4000,raw material ratio(PEG:EP)at 1.5:1,epoxy conversion rate of 71%;determine waterborne coating gloss is 128Gs,hardness is 2H,abrasion is 26mg/100r,impact resistance is 38kg·cm,flexibility is 3mm,adhesion is 6.56MPa;storage stability is level 5,freeze-thaw stability is level 5,dilution stability is 0.1%,centrifugal stability is level 5.Through the FT-IR and 1H NMR for the EP-PEG,it was proved that the PEG segment was grafted into the EP structure,and the microscopic morphology of the Latex and the paint film was observed by SEM,the size is uniform,Long-term storage,the coating is smooth and flat,Good curing cross-linking effect.(2)NCC blending modified EP-PEG,the best preparation process is:the content of NCC is 0.6%,determine gloss is 117Gs,hardness is 3H,abrasion value is 12mg/100r,adhesion is 7.42MPa,impact strength is 44kg·cm;TEM shows that NCC is distributed in EP-PEG emulsion evenly,but the SEM shows that the coating structure is not dense,and there is a gap between the coatings due to the presence of the NCC.Improved thermal stability by TG.(3)NCC copolymerizates modified EP-PEG,the best preparation process is:the content of NCC is 0.6%,the content of KH540 is I%,determine gloss is 98Gs,hardness is 4H,abrasion value is 6mg/100r,adhesion is 9.78MPa,impact strength is 48kg·cm;through FT-IR,EDX,it was proved that NCC has been grafted into the EP structure;secondly,the TEM can observe that the NCC is distributed uniformly in the EP-PEG without agglomeration.Improved thermal stability by TG. |
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