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Radical polymerization of methyl mcthacrylate (MMA) initiated with various diacyl peroxideamine systems was studied. Benzoyl peroxide (BPO) and lauroyl peroxide (LPO) were used as diacyl peroxide component, N,N-dimethyl aniline (DMA) and its para substituted derivatives, i.e., N,N-dimethyl-p-toluidine (DMT), p-hydroxymethyl-N,N-dimethyl aniline (HDMA), p-nitro-N,N-dimethyl aniline (NDMA) and p-dimethylamino benzaldehyde (DMAB) were used as amine components. It was found that the peroxide-DMT systems give higher rates of bulk polymerization R_p of MMA than the organic hydroperoxide-DMT systems with the following descending order BPO-DMT>LPO-DMT>CHP (cumene hydroperoxide)-DMT>TBH (tert-butyl hydroperoxide)-DMT. The aromatic tertiary amines possess obvious structural effect on the R_p values in the diacyl peroxideamine system. The overall activation energy of MMA polymerization was determined and thekinetics of polymerization of MMA initiated with BPO-DMT system was investigated. 相似文献
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<正> 有机过氧化物引发烯类单体的聚合,可以加入芳叔胺促进过氧化物的分解,提高聚合速度。其中最常用的芳叔胺有N,N-二甲苯胺(DMA)、N,N-二甲基对甲苯胺(DMT),本文采用过氧化二苯甲酰(BPO)、过氧化二月桂酰(LPO)、叔丁基过氧化氢(TBH)和过氧化苯甲酸叔丁酯(TBPB)四种过氧化物为引发剂进行甲基丙烯酸甲酯(MMA)的本体聚合,测得其聚合速度R_p的顺序为LPO>BPO>TBH>TBPB,但在添加芳叔胺DMT或脂环叔胺N-乙基哌啶(NEP)时,则聚合速度的顺序变为BPO-胺>LPO-胺>TBH-胺>TBPB-胺。添加这两种叔胺虽然都能促进聚合,但只对BPO引发剂有显著的影响,研究结果如下: 相似文献
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The polymerization of methyl methacrylate (MMA) initiated by organic peroxide and polymerizable aromatic tertiary amine such as N, N-di (2-α-methylacryloyloxy propyl)-p-toluidine (MP)_2PT binary system has been studied. It was found that the (MP)_2PT promotes MMA polymerization, and the kinetics of MMA polymerization fits the radical polymerization rate equation. Based on the ESR studies and the end-group analysis the initiation mechanism is proposed. 相似文献
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The polymerization of methyl methacrylate(MMA) initiated with piperidine derivatives,such as,piperidine(P),2,2,6,6-tetramethyl-4-hydroxyl piperidine(TMP),N-ethyl iperidine(NEP),1,2,2,6,6-pentamethyl-4-hydroxyl piperidine(PMP),and organic peroxides,such as,benzoyl peroxide(BPO),lauryl peroxide(LPO),f-butyl hydroperoxide (TBH),t-butyl peroxybenzoate(TBPB) systems was studied and discussed in this paper.The polymerization rate equation and the activation energy of polymerization were determined respectively. 相似文献
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P. C. Dwivedi Archana Srivastava R. S. Rathi 《Journal of polymer science. Part A, Polymer chemistry》1990,28(12):3279-3291
Polymerization of methyl methacrylate (MMA) with aliphatic primary amines and carbon tetrachloride has been investigated in th dimethylsulfoxide medium by employing a dilatometric technique at 60°C. The rate of polymerization (Rp) has been evaluated under the conditions, [CCl4]/[amine] < 1 and > 1. The kinetic data indicate possible participation of the charge transfer complexes formed between the amine + CCl4 and the amine + MMA in the polymerization of MMA. In the absence of CCl4 or amine, no polymerization of MMA was observed under the present experimental conditions. The polymerization of MMA was inhibited by hydroquinone, indicating a free radical initiation. The energy of activation varied from 32 to 58 kJ mol?1. 相似文献
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《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1435-1450
ABSTRACT The kinetics of the free radical bulk polymerization of methyl methacrylate (MMA) was studied by DSC, using the benzoyl peroxide (BPO)/amine initiation system. N,N dimethyl-4-aminophenethyl alcohol (DMPOH), which is a newly synthesized and used amine in the preparation of acrylic dental resins and bone cements was examined, and the results compared to the most commonly used in these applications amine, the N,N dimethyl-p-toluidine (DMT). For both amines, the effect of the molar ratio of BPO/amine and of the reaction temperature, on the polymerization kinetics was investigated. The prepared polymers were characterized by determination of the average molecular weights (M¯ n and M¯ w ) and molecular weights distribution (M¯ w /M¯ n ) using Gel Permeation Chromatography. DMPOH was found to lead in slightly higher polymerization rates, lower gel times and lower molecular weights than DMT. The values of these parameters for both amines were influenced by the molar ratio of BPO to amine, when the product of the concentrations of these was kept constant. The highest polymerization rate occurred in the lowest gel time, resulting in polymers with the lowest molecular weight, and was observed when a molar ratio of about 1.5 BPO/amine was used. However, the final monomer conversion was found to be independent of the molar ratio and amine used. The activation energy of polymerization was found to be 51.8 kJ/mol K for BPO/DMPOH and 47.1 kJ/mol K for BPO/DMT. 相似文献
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有机过氧化物-芳叔胺体系引发甲基丙烯酸甲酯聚合的研究 总被引:1,自引:2,他引:1
以过氧化二酰(BPO、LPO)或有机过氧化氢物(TBH、CHP)和芳叔胺如DMA或对位具有不同取代基的衍生物组成的引发体系进行MMA聚合,研究过氧化物与胺的结构对聚合的影响。结果表明,过氧化二酰的活性要比有机过氧化氢物大,其顺序为BPO>LPO>CHP>TBH。对于BPO-芳叔胺或LPO-芳叔胺体系,芳叔胺中给电子取代基能提高聚合速度,而吸电子取代基能降低聚合速度。测定了MMA聚合的总活化能E_α,BPO-芳叔胺体系时E_α=36-54kJ/mole,LPO-芳叔胺体系时E_α=56-71kJ/mole;还研究聚合动力学。 相似文献
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Polymerization of methylmethacrylate (MMA) with aminoalcohols, namely ethanolamine (EA), diethanolamine (DEA) and triethanolamine (TEA) in the presence of carbontetrachloride (CCl4) has been investigated in the dimethylsulfoxide (DMSO) medium by employing a dilatometric technique. The rate of polymerization (R
p) has been evaluated under the conditions
and > 1. The kinetic data reveal the possible participation of a charge-transfer complex in the polymerization reaction. In the absence of either CCl4 or amine, no polymerization of MMA was observed under the present experimental conditions. The polymerization of MMA was inhibited by hydroquinone, indicating a free radical initiation. 相似文献
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Aliphatic tertiary amino-group N-substituted acrylamides, N-acryl-N′-methylpiperazine (AMP)and N-methacryl-N′-methylpiperazine (MAMP) were synthesized directly from N-methylpiperazinewith corresponding acryloyl chlorides and characterized by elementary analysis of their picrates,~1H-NMR, IR and MS. AMP did not polymerize with benzoyl peroxide (BPO), but could poly-merize with lauroyl peroxide (LPO). The rate equation of the polymerization was given as R_P=K_P [AMP]~(1.5)[LPO]~(0.5) and the overall activation energy of this polymerization system was 10.8Kcal/mol. The redox nature of LPO with the monomer itself was suggested. Even though AMP and MAMP hardly proceed the polymerization initiated with BPO, butunder lower concentration would form redox system with BPO to initiate the polymerization of MMAreadily. The rate equation of the polymerization of MMA initiated with MAMP-BPO systemwas given as R_P=K_P [MMA] [MAMP}~(0.5) [BPO]~(0.5) and the overall activation energy was 10.2Kcal/mol. The analysis of the obtained polymers confirmed that MAMP not only initiated the poly-merization of MMA by combining with BPO, but also took part in the polymer chains impartingthem with better biocompatibility. 相似文献
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The charge-transfer complex formed between an amine and carbon tetrachloride can initiate the polymerization of vinyl monomers in a nonaqueous solvent such as dimethylsulfoxide. Here we use cyclopentylamine (CPA) and heptylamine (HA) as the donor compounds for charge-transfer initiation of the polymerization of methl methacrylate (MMA). The rate of polymerization Rp = k[MMA]1 [amine]0.5 [CCl4]0.5 when [CCl4] [amine] ≤ 1; when [CCl4] [amine] < 1, Rp becomes independent of [CCl4] and Rp = k[MMA]1.5 [amine]0.5. The average constant at 60°C for the polymerization of MMA in terms of monomer were (1.66 ± 0.03) × 10?5 and (1.46 ± 0.04) × 10?5 s?1 with CPA and HA, respectively, when [CCl4] [amine] ≤ 1, and (1.16 ± 0.04) × 10?5 and (1.39 ± 0.08) × 10?1 L/mol·s when [CCl4]/[amine] < 1. 相似文献
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Ruthenium trichloride (RuCl3 or RuIII) catalyzed polymerization of methylmethacrylate (MMA) initiated with n‐butylamine (BA) in the presence of carbon tetrachloride (CCl4) by a charge‐transfer mechanism has been investigated in a dimethylsulfoxide (DMSO) medium by employing a dilatometric technique at 60°C. The rate of polymerization (Rp) has been obtained under the conditions [CCl4]/[BA] ? 1 and [CCl4]/[BA] ? 1. The kinetic data indicate the possible participation of the charge‐transfer complex formed between the amine–RuIII complex and CCl4 in the polymerization of MMA. In the absence of either CCl4 or BA, no polymerization of MMA is observed under the present experimental conditions. The rate of polymerization is inhibited by hydroquinone, suggesting a free‐radical initiation. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 43: 70–77, 2011 相似文献
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A series of combinations of alkyl halide with tertiary amine such as ethyl α-bromophenylacetate/tris[2-(dimethylamino)ethyl)]amine (αEBP/Me6TREN), ethyl 2-bromoisobutyrate/triethylamine (EBiB/TEA), and ethyl 2-chloropropionate/N,N,N′,N′,N′′-pentamethyldiethylenetriamine (ECP/PMDETA) have been developed as novel free radical initiators and used for the polymerizations of methyl acrylate (MA), methyl methacrylate (MMA) and styrene (St). The effects of the structure of alkyl halide and tertiary amine on the polymerization of MA were investigated. Gel permeation chromatograph (GPC) and proton nuclear magnetic resonance (1H NMR) have been utilized to analyze the end group of the obtained poly(methyl acrylate). Electron spin resonance (ESR) spectroscopy was employed to identify the structure of the radicals produced by αEBP/Me6TREN, and the results indicated that αEBP reacted with Me6TREN via a single electron transfer (SET) nucleophilic mechanism to produce corresponding ethyl α-phenylacetate radicals which subsequently initiated the polymerization of MA. As both alkyl halide and tertiary amine are commercially available at low cost, non-explosive, and ease of use and storage in comparison with conventional azo, peroxide or persulfate initiators, the combination of alkyl halide and tertiary amine as a free radical initiator is promising for large-scale practical applications. 相似文献
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Paul E. Willard 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(1):33-41
Seven organic peroxide initiators for the polymerization of diallyl-o-phthalate prepolymers were studied using differential scanning calorimetry. Included were t-butyl perbenzoate, dicumyl peroxide, α,α′-bis(t-butyl peroxy) diisopropyl-benzene, 2,5-dimethyl-2,5-di(t-butyl peroxy) hexane, 2,5-dimethyl-2,5-di(t-butyl peroxy)hexyne-3, di-t-butyl peroxide, and t-butyl hydroperoxide. Heats of reaction and reaction rate constants are presented for each initiator at 1, 2, 3, and 4 phr of diallyl-o-phthalate prepolymers. The differences in reaction temperature and rate are discussed. Effects of four types of commonly used fillers (asbestos floats, ground quartz, calcium silicate, and clay) on the heats of reaction of diallyl-o-phthalate prepolymers using t-butyl perbenzoate and dicumyl peroxide initiators show the large inhibiting effect of untreated kaolinite clays on this polymerization. 相似文献
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Takaaki Sugimura Yuji Minoura 《Journal of polymer science. Part A, Polymer chemistry》1966,4(11):2735-2746
The effect of diphenyl thiourea (DPTU) on the radical polymerization of methyl methacrylate (MMA) has been studied in benzene solution at 50°C. with the use of cumene hydroperoxide (CHP), p-menthane hydroperoxide (PMHP), tert-butyl perbenzoate (tBPBz), di-tert-butyl peroxide (DBP), and dicumyl peroxide (DCP) as initiators. In the CHP-initiated polymerization, the rate of polymerization increased appreciably on addition of DPTU with a linear dependence on the square root of DPTU concentration up to a maximum which was observed when the ratio of the concentration of CHP to DPTU was 2.5. Then the rate decreased gradually with increasing DPTU concentration in the range greater than the above ratio. It was found from kinetic studied that the overall polymerization rate Rp was expressed by the equation: Rp = K[peroxide]1/2 [DPTU]1/2[MMA], where K is the rate constant, α = 1.2 for CHP and α = 1.0 for tBPBz. It was thought that the acceleration effect observed was due to a redox reaction caused by the interaction of a peroxide–monomer and/or a peroxide–solvent complex with DPTU, and the decrease in the polymerization rate which was observed over a certain concentration of DPTU was due to the action of the oxidized product of DPTU as a transfer agent. The effect of substituents was studied by using para and meta-substituted DPTU. It was found that the polymerization rate increased as electron-donating substituents are added to the benzene ring of DPTU with considerable dependence on Hammett's equation (p = ?0.36). The acceleration effect is also observed for PMPH-and tBPBz-initiated polymerizations, whereas the DCP- and DBP-initiated systems show no effects on the polymerization rate. 相似文献
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Polymerization of methyl methacrylate (MMA) with triethanolamine (TEA) and carbon tetrachloride has been investigated in the presence of PdCl2 and in a dimethylsulfoxide (DMSO) medium by employing a dilatometric technique at 60°C. The rate of polymerization has been obtained under the conditions [CCl4]/[TEA] ≤ 1. The kinetic date indicate the possible participation of the charge‐transfer complex formed between the {amine–PdII} complex and CCl4 in the polymerization of MMA. In the absence of either CCl4 or amine, no polymerization of MMA was observed under the present experimental conditions. The rate of polymerization was inhibited by hydroquinone, suggesting a free‐radical initiation. © 2000 John Wiley & Sons, Inc. Int J Chem Kinet 32: 171–177, 2000 相似文献