Study On Synthesis And Properties Of UV-Curable Waterborne Fluorinated Polyurethane

Waterborne polyurethane with water as the medium is a kind of green environmental protection coatings. Because of its excellent properties of chemical resistance, abrasion resistance, thermal stability, waterborne polyurethane has been widely used in many fields. However, the introduction of hydrophilic groups into waterborne polyurethane leads to the decline of the coating properties. UV curing has a number of advantages, such as fast curing speed, low curing temperature, environment friendly, energy saving, wide application, high efficiency, low cost, small equipment volume etc. Due to the excellent properties, such as super hydrophobic, low polarizability, good heat resistance, flame resistance and heat resistance, fluorocarbon materials have potential applications in many areas. This thesis has developed a UV curable waterborne fluorinated polyurethane coatings through introducing light curing group and fluorine. The study has important significance.Two kinds of UV curable waterborne fluorined polyurethane resins were synthesized in this thesis. One of them is GMA modified waterborne fluorinated polyurethane. Its raw materials are toluene diisocyanate (2,4-TDI), polyether diol,2,2-double dimethylol propionic acid (DMPA), thirteen fluorine octanol, glycidyl methacrylate (GMA). The other is the organic fluorine modified UV curable waterborne polyurethane. Its raw materials are of three hydroxymethyl propane (TMP), maleicanhydride (MA), toluenediisocyanate (2,4-TDI), polyetherdiol,1,4-butanediol, thirteen fluorine octanol. This thesis investigated the effects of catalyst, reaction temperature, reaction time, raw material amount of neutralization degree of synthesis conditions on the properties of emulsion. Effect of fluorine contents on thermal properties, mechanical properties of the coating were also studied. The main research contents are as follows:By using toluene diisocyanate (2,4-TDI), polyether diol,2,2-doubledimethylol propionic acid (DMPA), thirteen fluorine octanol, glycidyl methacrylate (GMA), GMA modified waterborne fluorinated polyurethane was synthesized.The researchers characterized the morphology and composition of the surface, the particle size of emulsion, and the thermal properties of the film. PCS analysis shows that the particle size of emulsion increases as the increase of fluorine content. DSC and TG show that the thermal stability of the film enhances as the increase of the content of fluorine. The performance test results show that the coating is resistant to water absorption, acid and alkali. The resistance and hardness of the coating have been improved sigficantly as the increase of fluoride concentration. However, the adhesion and impact resistance intensity decreased slightly with the increase of fluoride concentration. When GMA dosage is increasing, the emulsion viscosity and coating hardness increased. But the impact resistance decreased slightly. As the increase of degree of neutralization, the emulsion became transparent and stable.An unsaturated hydrophilic glycol was also synthesized by using three hydroxy methyl propane (TMP), maleic anhydride (MA). The unsaturated hydrophilic glycol, 2,4-toluene diisocyanate (TDI), polyether diol,1,4-butanediol, thirteen fluorine octanol are the raw material for an organic fluorine modified UV curable waterborne polyurethane. The structure of hydrophilic glycol was characterized by using FT-IR. PCS analysis, and the results showed-that the particle size of the emulsion increases as the increase of fluorine content. The particle size of emulsion decreases as the increase of DMPA content. The results of characterization show that the thermal properties of fluorinated polyurethane coating are excellent. Contact angle measurements show that the film contact angle increases as the increase of fluorine content, which suggests the enhance thehydrophobic properties of the film.