Study On Synthesis And Properties Of Non-isocyanate Polyurethane Acrylate Monomers

Polyurethane acrylate(PUA) is a very important UV-curing materials, has the characteristics both of polyurethane and acrylate materials,widely used in UV-curing coatings, printing ink, adhesive, etc. The production of traditional polyurethane acrylate need to ues isocyanate, the isocyanate is harmful to humans and the enviroment, therefore the development of environmentally friendly non-isocyanate polyurethane (NIPU) materials become the research hotspot in domestic and aboard in recent years. In this paper, NIPU was synthesised, then use NIPU to prepare low viscosity, high activity polyurethane acrylate monomers, used as the active diluent for UV-curing coatings.In this paper, ethylene carbonate(EA), n-butylamine(BA) and acryloyl chloride(AC) are adopted as raw materials, first the EA and BA for amine ring-opening reaction to prepare non-isocyanate polyurethane (NIPU1), then the NIPU1and AC for esterification reaction to prepare a mono-functional polyurethane acrylate reactive monomer(NIPUA1), the structure of product was confirmed by FT-IR and1H-NMR characterization. The synthesis process was optimized by single-factor experiments. The optimal conditions of the synthesis of NIPU1are as follows:ethanol as solvent, n(BA):n(EA)=1.2:1, for4h at30℃, the yield was92.3%. The optimal conditions of the synthesis of NIPUA1are as follows:ethyl acetate as solvent, triethylamine as the bind acid agent, n(NIPU1): n(AC)=1:1.2, AC was added dropwise in an ice bath, for4h at25℃, inhibitor dosage is0.04%of the total mass of the raw materials, the yield was65%.In this paper, ethylene carbonate(EA), diethanolamine(DEA), acryloyl chloride(AC) are adopted as raw materials, first the EA and DEA for amine ring-opening reaction to prepare non-isocyanate polyurethane (NIPU2), then the NIPU2and AC for esterification reaction to prepare a trifunctional polyurethane acrylate reactive monomer(NIPUA2), the structure of product was confirmed by FT-IR and1-NMR characterization. The synthesis process was optimized by single-factor experiments. The optimal conditions of the synthesis of NIPU2are as follows:dioxane as the solvent, about100ml, n(EA):n(DEA)=1:1, for4h at85℃, the yield was87.8%. The optimal conditions of the synthesis of NIPUA2are as follows:acetone as the solvent, triethylamine as the bind acid agent, n(NIPU2): n(AC)=1:3.9, AC was added dropwise in an ice bath, then for3h at30℃, inhibitor dosage is0.06%of the total mass of the raw materials, the yield was43.2%.In this paper, use NIPUA1and NIPUA2with the same oligomers for UV-curing, and the curing speed, hardness, water resistance and adhesion of the film was determined. The results are as follows:the curing time of useing NIPUA1or NIPUA2are better than no active monomer, improved more than10s, and the curing time of using NIPUA2is better than using NIPUA1, improved about8s; the hardness of the film using NIPUA1is the same with not using active monomer, all for2H, the hardness of the film using NIPUA2is improved to4H; if just let the oligomers for UV-curing, the water resistance of the film is poor, the hydrophilic of NIPUA1and NIPUA2are weak, so if add the active monomers to the coating, the the water resistance of the film is better; the using of NIPUA1has little effect on the adhesion of the film, the shrinkage of the film using NIPUA2become larger, so the adhesion is worse.