Reverse atom transfer radical polymerization of methyl acrylate in the presence of a conventional radical initiator (2,2′-azoisobutyronitrile, AIBN) in bulk was successfully implemented via a new polymerization procedure. The system first reacts at 65–70°C for ten hours, then polymerizes at 100°C. Various mole ratios of AIBN to CuIICl2 were used in this work, all of which result in a well-controlled radical polymerization with high initiation efficiency and narrow molecular weight distribution, i.e., the polydispersity is as low as M̄w/M̄n = 1.36. 相似文献
Abstract Copolymerization of 2-ethylhexylacrylate (2-EHA) and styrene (Sty) initiated by α,α′-azobisisobutyronitrile (AIBN) was carried out at 60, 65, and 70 ± 0.1°C in bulk in the presence of zinc chloride (ZnCl2). Rp was a direct function of [ZnCl2] and temperature. Rp showed an initial increase with [monomers] followed by a subsequent decrease after a maximum was reached. The accelerating effect of ZnCl2 was predicted by a lowering of the activation energy from 42.78 to 34.38 kJ·mol?1 and an increase in the specific rate constants ratio (k2p/kt) from 4.64 to 5.83 L·mol?1·s?1. The product of the reactivity ratios of the two monomers was 0.018 and 0.648, favoring alternating and random copolymer structures, respectively. The copolymerization reaction mechanism was a radical complex. Rheological investigations favored Bingham and Ostwald models for the flow behaviors of alternating and random copolymers, respectively. 相似文献
N-phenyl-α-methylene-β-lactam (PML), a cyclic analog of N,N-disubstituted methacrylamides which do not undergo radical homopolymerization, was synthesized and polymerized with α,α′-azobis (isobutyronitrile) (AIBN) in solution. Poly (PML) (PPML) is readily soluble in tetrahydrofuran, chloroform, pyridine, and polar aprotic solvents but insoluble in toluene, ethyl acetate, and methanol. PPML obtained by radical initiation is highly syndiotactic (rr = 92%), exhibits a glass transition at 180°C, and loses no weight upto 330°C in nitrogen. The kinetics of PML homo-polymerization with AIBN was investigated in N-methyl-2-pyrrolidone. The rate of polymerization (Rp) can be expressed by Rp = k[AIBN]0.55[PML]1.2 and the overall activation energy has been calculated to be 87.3 kJ/mol. Monomer reactivity ratios in copolymerization of PML (M2) with styrene (M1) are r1 = 0.67 and r2 = 0.41, from which Q and e values of PML are calculated as 0.60 and 0.33, respectively. 相似文献
A kinetic study of radical polymerization of vinyl mercaptobenzothiazole (VMBT) with α,α′-azobisisobutyonitrile (AIBN) at 60°C was carried out. The rate of polymerization (Rp) was found to be expressed by the rate equation: Rp = k[AIBN]0.5 [VMBT]1.0, indicating that the polymerization of this monomer proceeds via an ordinary radical mechanism. The apparent activation energy for overall polymerization was calculated to be 20.9 kcal/mole. Moreover, this monomer was copolymerized with methyl methacrylate, acrylonitrile, vinyl acetate, phenyl vinyl sulfide, maleic anhydride, and fumaronitrile at 60°C. From the results obtained, the copolymerization parameters were determined and discussed. 相似文献
Novel 9-amino-3-substituted-1,2,3,4-acridin-1-one derivatives and 9,14-diamino-7-substituted-7,8-dihydroquinolino[2,3-a]acridine derivatives were synthesized by the condensation reaction of 5-substituted-1,3-cyclohexanedione with 2-aminobenzonitrile and substituted 2-aminobenzonitrile using p-toluenesulfonic acid, K2CO3, and Cu2Cl2 as catalysts. The structures of all compounds were characterized by elemental analysis, infrared, mass spectrometry, and 1H and 13C NMR spectra. The crystal and molecular structures of 6, 14-diamino-3,4,11,12-tetramethoxy-7-phenyl-7,8-dihydroquinolino[2,3-a]acridine 5a have been determined by single-crystal x-ray diffraction analysis. The crystal of compound 5a belongs to triclinic with space group P-1, a = 1.06168(15) nm, b = 1.16951(17) nm, c = 1.6020(2) nm, α = 71.380(3)°, β = 77.686(3)°, γ = 66.743(3)°, Z = 2, V = 1.7231(4) nm3, R1 = 0.1060, and wR2 = 0.2192. 相似文献
p-Divinylbenzene (DVB) 13C-labeled at the methine carbon of the vinyl group was copolymerized in suspension with styrene at 70, 70–95, and 135–155°C using 2,2′-azobisisobutyronitrile (AIBN) as the initiator. The number of unreacted vinyl groups in each copolymer was determined by 13C CP–MAS NMR analysis of solid samples, direct polarization 13C-NMR analysis of CDCl3-swollen gels, and bromination. Results from the three methods agree methods agree qualitatively. Even the 1% DVB-crosslinked networks contained 40% unreacted DVB-vinyl groups when prepared by high conversion polymerization at 70°C and 16% unreacted DVB-vinyl groups when polymerization was finished at 95°C. The analyses were also applied to some commercial crosslinked polystyrenes. Every sample examined contained pendent vinyl groups 相似文献
2-Mercaptobenzothiazolyl methacrylate (MBTM) was synthesized by the reaction of 2-mercaptobenzothiazole and methacrylyl chloride in tetrahydrofuran at -18°C. MBTM was found to polymerize in the presence of 2,2′-azobisisobutyronitrile (AIBN), n-BuLi, and UV light. From the kinetic studies of radical polymerization of MBTM with AIBN in benzene at 60°C, the overall activation energy was determined to be 18.9 kcal/mole, and the rate of polymerization (R) was expressed as Rp = k[AIBN]0.5 [MBTM], where k is the overall polymerization rate constant. From these results this polymerization was confirmed to proceed via an ordinary radical mechanism. This monomer (M2) was also copolymerized radically with styrene (M1) at 60°C, and the resulting copolymerization parameters were determined as r1 = 0.042, r2 = 0.20, Q2 = 4.09, and e2 = 1.39. The thermal stability and the photodegradation behavior of the polymers were examined, and they were compared with those of the related polymers. 相似文献
α-Methylene-N-methylpyrrolidone (α-MMP) was synthesized and homopolymerized by bulk and solution methods. The poly(α-MMP) is readily soluble in water, methanol, methylene chloride, and dipolar aprotic solvents at room temperature. Thermogravimetric analysis of poly(α-MMP) showed a 10% weight loss at 330°C in air. The kinetics of α-MMP homopolymerization and copolymerization were investigated in acetonitrile, using azobisisobutyronitrile (AIBN) as an initiator. The rate of polymerization Rp could be expresed by Rp = k[AIBN]0.49[α-MMP]1.3. The overall activation energy was calculated to be 84.1 kj/mol. The relative reactivity ratios of α-MMP (M2) copolymerization with methyl methacrylate (r1 = 0.59, r2 = 0.26) in acetonitrile were obtained. Applying the Q-e scheme led to Q = 2.18 and e = 1.77. These Q and e values are larger than those for acrylamide derivatives. 相似文献
2-Vinyl-1,3-dioxolane was polymerized by use of α,α′-azobisisobutyronitrile (AIBN) or by γ-ray irradiation. The polymer obtained was white amorphous powder which melted at ca. 70°C. and was soluble in chloroform, acetone, and p-dioxane. The infrared spectrum of the polymer indicated peaks at 1735 cm.?1 characteristic of the carbonyl group, and at 1200–1000 cm.?1 characteristic of the acetal group, while no absorption at 990 and 3100 cm.?1 due to the vinyl group was observed. The spectra of the polymers obtained by AIBN and by γ-ray irradiation were essentially identical. The saponified product of the polymer was white powder and its reduced viscosity was a little larger than that of the original polymer. These results indicate that the polymer has no ester unit in the main chain. The results of gas chromatographic analysis of the saponified product of the polymer, indicate the presence of a small amount of ethyl alcohol. The results of the saponification showed that the ester content in the polymer varied from 7 to 25% depending upon the polymerization temperature. These results indicate that 2-vinyl-1,3-dioxolane polymerized by AIBN or by γ-irradiation with two modes of vinyl and hydrogen migration, yielding a copolymer having the unit structures 相似文献
The thermal copolymerization of N-vinylcarbazole (VCz) with 2-dimethylaminoethyl methacrylate (DMAEM) initiated by α,α′-azobisisobutyronitrile (AIBN) in solution in tetrahydrofuran at 60°C has been studied. Different compositions of copolymer were prepared and characterized by UV, IR, and 1H-NMR spectroscopy, viscosity measurements, and thermal studies. The estimation of the composition of VCz and DMAEM in the copolymer was carried out by UV spectroscopy. The reactivity ratio of VCz (r1) and DMAEM (r2) was determined by the methods of Mayo and Lewis, Kelen and Tüdös, and Tidwell and Mortimer. 相似文献
Optically active N-α-methylbenzylmaleimide (MBZMI) was prepared with maleic anhydride and d-(+)-α-methylbenzylamine. The polymerizations of MBZMI were carried out with α,α′-azobisisobutyronitrile (AIBN) and n-butyllithium (n-BuLi) in tetrahydrofuran (THF). The specific rotations of the polymers obtained by AIBN and n-BuLi initiator were +11.1° to +13.0° and ?57.0° to ?89.2°, respectively. The weight-average molecular weights (Mw) for the polymers were between 4200 and 8000. Furthermore, MBZMI was copolymerized with styrene (ST) and methyl methacrylate (MMA) with AIBN in THF at 50°C to obtain optically active copolymers. The monomer reactivity ratios of MBZMI (M1) with ST (M2) were obtained as r1 = 0.027, r2 = 0.094 in the MBZMI–ST and r1 = 0.15, r2 = 1.54 in the MBZMI–MMA system. The Q-e values for MBZMI were Q1 = 0.78, e1 = 1.62. All the polymers and copolymers were found to show a weakly negative circular dichroism (CD) peak at about 250 nm and a strongly positive CD peak at about 220 nm. 相似文献