Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' a...Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous so-lutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.展开更多
The urethane acrylate(UA) was made of poly(tetramethylenc oxide), 4,4’-diphenylmethane diisocyanate, and 2-hydroxyethyl methacrylate. A series of poly(methyl methacrylate) / urethane acrylate copolymers was prepared ...The urethane acrylate(UA) was made of poly(tetramethylenc oxide), 4,4’-diphenylmethane diisocyanate, and 2-hydroxyethyl methacrylate. A series of poly(methyl methacrylate) / urethane acrylate copolymers was prepared by using a redox initiating system. The copolymers had cross linked structures and two-phase morphologies as indicated by the results of the dynamic mechanical measurement and swelling test.展开更多
Urethane acrylate anionomer (APUA) as a kind of new type polymerizable emulsifier was synthesized using 2,4-toluene diisocyanate (TDI), polypropylene glycol (PPG), 2-hydroxyethyl methacrylate (HEMA) and dimethylolprop...Urethane acrylate anionomer (APUA) as a kind of new type polymerizable emulsifier was synthesized using 2,4-toluene diisocyanate (TDI), polypropylene glycol (PPG), 2-hydroxyethyl methacrylate (HEMA) and dimethylolpropionic acid (DMPA). The critical micelle concentration (CMC) of APUA was measured by the methods of conductance and surface tension. The comparative studies between polymerizable emulsifier AUPA and conventional emulsifier sodium dodecyl sulfate (SDS) were carried out in the emulsion polymerization of methyl methacrylate (MMA). Polymerization kinetics, stability, size and morphology of the latex particles were investigated. It was found that in APUA both water soluble initiator potassium persulfate (KPS) and oil soluble initiator 2,2'-azobisisobutyronitrile (AlBN) can start the reaction of MMA, and the polymerization rate and yield were very high. On using AlBN as an initiator, the conversion-time behavior of MMA with APUA as emulsifier was different to that of SDS as emulsifier, signifying a different nucleation mechanism of the polymer latex particle. The average size of the two kinds of particles is about 50 nm. The particle size decreases with increasing emulsifier concentration. On using KPS as the initiator, APUA as emulsifier, cross-linking hydrogel of PMMA would be formed, but SDS was used as emulsifier and the hydrogel of PMMA was not present.展开更多
文摘Two kinds of water-soluble and ultraviolet (UV) curable oligomers were synthesized and characterized. The oligomers were evaluated as resins for water-based UV curable coating. The rheology of the two oligomers' aqueous so-lutions was investigated in terms of solid fraction, pH dependence, and temperature dependence. The solutions were found to be Newtonian fluid showing rather low viscosity even at high solid fraction of 0.55. The drying process of the coatings and the properties of the cured coatings were studied by comparing them with water-dispersed UV-curable polyurethane methyl acrylate. It was evident that the water-soluble coating dried more slowly; and that the overall properties were inferior to those of the water-dispersed coating.
文摘The urethane acrylate(UA) was made of poly(tetramethylenc oxide), 4,4’-diphenylmethane diisocyanate, and 2-hydroxyethyl methacrylate. A series of poly(methyl methacrylate) / urethane acrylate copolymers was prepared by using a redox initiating system. The copolymers had cross linked structures and two-phase morphologies as indicated by the results of the dynamic mechanical measurement and swelling test.
文摘Urethane acrylate anionomer (APUA) as a kind of new type polymerizable emulsifier was synthesized using 2,4-toluene diisocyanate (TDI), polypropylene glycol (PPG), 2-hydroxyethyl methacrylate (HEMA) and dimethylolpropionic acid (DMPA). The critical micelle concentration (CMC) of APUA was measured by the methods of conductance and surface tension. The comparative studies between polymerizable emulsifier AUPA and conventional emulsifier sodium dodecyl sulfate (SDS) were carried out in the emulsion polymerization of methyl methacrylate (MMA). Polymerization kinetics, stability, size and morphology of the latex particles were investigated. It was found that in APUA both water soluble initiator potassium persulfate (KPS) and oil soluble initiator 2,2'-azobisisobutyronitrile (AlBN) can start the reaction of MMA, and the polymerization rate and yield were very high. On using AlBN as an initiator, the conversion-time behavior of MMA with APUA as emulsifier was different to that of SDS as emulsifier, signifying a different nucleation mechanism of the polymer latex particle. The average size of the two kinds of particles is about 50 nm. The particle size decreases with increasing emulsifier concentration. On using KPS as the initiator, APUA as emulsifier, cross-linking hydrogel of PMMA would be formed, but SDS was used as emulsifier and the hydrogel of PMMA was not present.
