| In this paper, 4-acrylamido-2,2,6,6-tetramethylpiperidine (AATP) and 4-mathacrylamido-2,2,6,6-tetramethylpiperidine (MATP) have been synthesized and the structures and composition of AATP and MATP have been characterized by FT-IR, 'H-NMR and elemental analysis.The reaction kinetics of photoinduced bulk polymerization of AATP in melting state has been studied by using photo-DSC (DPC) technique. The results have shown that the conversion and the rate of AATP photopolymerization are obviously affected by the reaction condition such as temperature, incident light intensity and concentration of photoinitiator etc. Darocur1173 is the available initiator and the optimum concentration of Darocur1173 is 0.5~1.0 wt%. Under given condition, the rate of AATP photopolymerization is proportional to the square root of photoinitiatorconcentration Cpi0.5 and incident light intensity Io0.5 , respectively. The kineticparameters of photoinduced bulk polymerization for AATP were measured at the steady and non-steady state. The rate constant for termination k, is much larger than that for propagation kp ( kt /kp = 3.43~33.57). kp and kt is increased with theconversion increasing in the reaction system. kp and kl is 2.22-7.96 102 and0.08~2.67xl04(L/mol.s) corresponding to a conversion from 4.00 % to 15.68 %, respectively. These values are within the range of corresponding parameters typicalfor a free radical polymerization. The induce time of the reaction system is decreased with the increment of photoinitiator concentration and incident light intensity respectively. Because of apparent activation energy of the reaction system is negativebe measured], the rate of AATP photopolymerization is decreased with increment of the temperature from 110 to 150 and the irradiating time of that is prolonged.The photo-induced copolymerization of methyl acrylate (Mi, for short MA) and 4-acrylamido-2,2,6,6-tetramethyl-piperidine (M2, for short AATP) in pyridine solution has been studied. The composition of MA/AATP copolymers was determined with 'H-NMR method. According to the composition of poly (MA-co-AATP), thecopolymerization reactivity ratios are calculated as 0.92 < r1 < 0.95 and0.50 < r2 < 0.66 by Mayo-Lewis method, as same as r1 = 0.92 and r2 = 0.54 by extending Kelen-Tudos method. The results have shown that the reactivity ratios of both MA and AATP monomer are less than 1, respectively, such as r1 < 1 and r2 < 1, the performance of MA/AATP copolymerization system is non-ideal azeotropic copolymerization that has a azeotropic point at f1 = 0.73 . On the basis of the reactivity ratios of two monomers, the sequence distribution in the MA/AATP copolymers is obtained. For, the probability of the sequence of 1 unit of MA in the copolymer chain is 80 %, the monomer unit of MA is mostly separated by the sequence of AATP; and for f2 =0.5, the alternating tendency prevails and a largenumber of mono-sequences are formed; and further to f2 =0.1, the probability of thesequence of 1 unit of AATP in the copolymer chain is 95 %, the monomer unit of AATP is interspersed with the sequence of 1 unit in the chain of MA.The UV-curing performances of the aromatic polyurethane acrylate coatings containing r-HALS, AATP or MATP, as light stabilizers, have been studied. The results have shown that oxygen has a critical effect on the UV-curing process of the aromatic PUA coatings containing r-HALS. The UV-curing conversion curve of thearomatic PUA with 5.0 wt% r-HALS in air is sharply lower than that without 5.0 wt% r-HALS. The increasing concentration of r-HALS in system leads to the decreasing conversion of the aromatic PUA UV-cured in air, however, the decrease in conversion is negligible when the concentration of r-HALS is less than 2.0 wt%. The two kind of r-HALS show the satisfactory photo-stabilizing performance in the artificial accelerating photo-aging of the aromatic PUA coatings. Yellowness Index (YI) of the PUA coatings containing 1.0 wt% r-HALS is lower than the blank sample, and the sample containi...
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