| The present thesis was aimed on the synthesis of silicon-containing acrylate, silicon-containing cycloaliphatic epoxy resin and silsesquioxane-based organic-inorganic hybrid urethane acrylate, and study on their photopolymerization kinetics, thermal degradation behavior, flame retardance as well as applications in UV curable coatings. A series of semi-crystalline hyperbranched poly (ester-amide)s were also synthesized and their application in UV-curable powder coating was studied. The detailed outline is elaborated as follows:The silicon-containing multifunctional acrylates, tri(acryloyloxyethyloxy) phenyl silane (TAEPS) and di(acryloyloxyethyloxy) methyl phenyl silane (DAEMPS) were synthesized and their molecular structures were confirmed by FTIR,1H NMR, 13C NMR and 29Si NMR spectroscopic analysis. The obtained TAEPS and DAEMPS were blended with a commercial epoxy acrylate (EB600) in different ratios to formulate a series of silicon-containing UV-curable resins. The maximum photopolymerization rate, which was monitored by Photo-DSC, increased along with the increase of TAEPS or DAEMPS content, while the final unsaturation conversion decreased. The limiting oxygen index (LOI) values of UV cured film increased from 21 for EB600 to 30 above for silicon-containing resins, which indicated that the addition of TAEPS or DAEMPS can efficiently enhance the flame retardancy of EB600. The char yields of cured TAEPS and DAEMPS films at 800℃measured under nitrogen atmospheres were two times and one times, respectively, higher than that of EB600. The glass transition temperatures of the UV-cured films increased with the increase of TAEPS content, and decreased with the increase of DAEMPS content. The tensile strength decreased with the increase of TAEPS or DAEMPS content, while the elongation-at-break increased.A novel silicon-containing trifunctional cycloaliphatic epoxide resin tri(3,4-epoxycyclohexylmethyloxy) phenyl silane (TEMPS) was synthesized via "transetherification and oxidation" method and characterized by FTIR,1H NMR, C NMR and 29Si NMR spectroscopic analysis. The obtained resin was then blended with bisphenol A epoxy resin (EP828) in different ratios to formulate a series of silicon-containing UV-curable resins. The data from the dynamic mechanical thermal analysis showed that TEMPS had good miscibility with EP828. The Tg and Ts both decreased from 138℃and 93℃for pure EP828 to 122℃and 79℃for sample with 80% TEMPS loading, respectively. The elongation-at-break increased with the increase of TEMPS content, while the tensile strength showed an opposite trend. The limiting oxygen index (LOI) values of cured film increased from 22 for EP828 to 30 for silicon-containing resins, which indicated that the addition of TEMPS can efficiently enhance the flame retardancy of EP828. The temperature at the maximum rate of weight loss Tmax2 increased with increasing TEMPS content. The char yields at 800℃measured under air atmospheres increased from 0% for pure EP828 to 14% for cured films with 80% TEMPS loading. Their flame retardant performance arise partly from the dilution function to more combustible organic gases, and partly from the barrier effect by the silicaceous residues formed in an advancing flame. While heating, the low surface energy of silicon migrates to the surface of coated film, following by the formation of a protective layer with high heat resistance. The high-performance char acts as an insulator and mass transport barrier, which can cut off the heat and oxygen transfer, and thus effectively improve the flame retradance of UV-cured resin.The silsesquioxane-based hybrid urethane acrylate (SHUA) was synthesized by modifying silsesquioxanebased hybrid polyol (SBOH) with the half adduct of isophorone diisocyanate and 2-hydroxyethyl acrylate, and characterized by FTIR and 'H NMR spectroscopy. The SHU A was mixed with a phosphorus-containing trifunctional acrylate (TAEP) with different ratios to prepare a series of UV-curable organic-inorganic hybrid resins. Both the maximum photopolymerization rate and final unsaturation conversion in the UV-cured films determined by photo-DSC decreased along with the increase of SHUA content. The data from the dynamic mechanical thermal analysis showed that SHUA had good miscibility with TAEP. Both the storage modulus in rubbery state and Tg first increased and then decreased along with the addition of SHUA content. The sample with 10% SHUA loading had the highest Tg of 150℃. The limiting oxygen index (LOI) values of all test samples were above 30. The char layer of sample with 20% SHUA loading had the maximum degree of expansion. The char yield of sample with 40% SHUA loading at 850℃was five times higher than that of TAEP. The elongation-at-break increased with the increase of SHUA content, while the tensile strength first increased and then decreased. The sample with 5% SHUA loading had the highest tensile strength of 21.6 MPa.Through thermal polycondensation from succinic anhydride as an AA'monomer and tris-(hydroxymethyl)aminomethane as a CB3 monomer in the absence of catalyst and solvent, hyperbranched poly (ester-amide) (HP) was synthesized and its structure was characterized by1H NMR and GPC. The calculated hydroxyl number of HP was 488 mg KOH/g. A series of semi-crystalline hyperbranched poly(ester-amide)s (HP-LχDy) was obtained by modifying hydroxyl end groups of HP with IPDI-C18 and IPDI-HEA in different ratios. HP is amorphous, while HP-LχDy is semi-crystalline due to the introduction of long alkyl chains. The degree of crystallinity increased with increasing the substitution degree of long alkyl chains emitting from the spherelike interior. The Tg and Tm of HP-LχDy were about 40℃and 120℃. The maximum photopolymerization rate, which was monitored by Photo-DSC, increased along with the increase IPDI-HEA content, while the final unsaturation conversion decreased.
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