共查询到19条相似文献,搜索用时 140 毫秒
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N-甲基-N-(2-甲基丙烯酰氧乙基)-对-甲苯胺对甲基丙烯酸甲酯聚合的影响 总被引:2,自引:2,他引:2
<正> 我们曾报道可聚合的芳叔胺N-甲基-N-(2-甲基丙烯酰氧乙基)苯胺(MEMA)与有机过氧化物如过氧化二苯甲酰(BPO)、过氧化二月桂酰(LPO)组成氧化还原引发体系用于甲基丙烯酸甲酯的聚合。虽然文献报道了N-甲基-N-(2-甲基丙烯酰氧乙基)-对-甲苯胺(MEMT)的合成,但没有研究它对甲基丙烯酸甲酯自由基聚合的影响。本文研究了MEMT对BPO或LPO引发MMA聚合的影响,从聚合动力学研究表明BPO/MEMT组成氧化还原引发体系。其引发机理与BPO/MEMA很相似。 相似文献
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本文研究了4′-甲氧基-4-重氮二苯胺(VB)金属复盐的稳定性,提出红外密度比值(D),热分解温度和光、热分解指数作为稳定性的量度。本文认为,4′-甲氧基-4-重氮二苯胺盐的分解为异裂反应。感光性能试验指出,感光胶片保存性参数与重氮盐稳定性参数之间有良好的相关性。 相似文献
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The graft copolymerization of 4-vinylpyridine (4-VP) onto partially car-boxymethylated cotton (PCMC), having different carboxymethyl contents, was investigated. Under similar reaction conditions, both the graft yield and eerie ion consumption increased by increasing the degree of substitution of carboxymethyl groups of PCMC up to a value of 0.11, beyond which grafting and Ce(IV) consumption decreased. Proof for grafting onto PCMC was provided through IR analysis. the eerie salt-initiated polymerization of 4-VP in the absence of PCMC was also studied. Three series of homo-polymerization reactions of 4-VP directly initiated by eerie ammonium nitrate were carried out with varying reaction times. Each series was run at a different nitric acid concentration. Both conversion and eerie ion consumption, as well as molecular weight, increased with reaction time. Increasing the nitric acid concentration increased both conversion and eerie ion consumption while the molecular weight decreased. 相似文献
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<正> 虽然Santappa等早已报道Ce~(4+)(高氯酸铈)/甲醛体系能引发丙烯腈(AN)、甲基丙烯酸甲酯(MMA)的聚合,但对醛的活性以及参与引发单体聚合的自由基都未有详细报道,近来孙燕慧等发现脂肪醛能显著促进Ce~(4+)(硝酸铈铵CAN)引发丙烯酰胺(AAM)的聚合,而且醛的活性远大于相应的醇。至于芳香醛对于Ce~(4+)引发烯类单体的聚合的影响也未见详细报道。本文扼要报道苯甲醛(BA)及其衍生物对-硝基苯甲醛(PNBA)、间-硝基苯甲醛(MNBA)、间-溴苯甲醛(MBBA)、对-氯苯甲醛(PCBA)对Ce~(4+)(CAN)存在下丙烯酰胺聚合的影响,测定了其聚合速率,以UV吸收光谱、ESR波谱测定 相似文献
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J. C. Salamone B. Snider W. L. Fitch 《Journal of polymer science. Part A, Polymer chemistry》1971,9(6):1493-1504
The mechanism of the spontaneous polymerization of 4-vinylpyiridine on quaternization or protonation has been investigated. Results indicate that initiation is caused by the nucleophilic attack of 4-vinylpyridine on the double bond of 4-vinylpyridinium ion. It was shown that halide ions do not contribute significantly to the initiation. In the case of acid salts of 4-vinylpyridine a hydrogen-transfer polymerization occurred to give an ionene polymer with pyridinium units in the main chain. The “matrix” polymerization of 4-vinylpyridine on poly(phosphoric acid) or poly(acrylic acid) also resulted in ionene formation. Conditions under which stable 4-vinylpyridinium salts can be obtained are discussed. 相似文献
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在稀土体系催化下的丁二烯聚合动力学 总被引:1,自引:0,他引:1
本文应用键谷勤聚合动力学公式进行动力学研究。求出了活性中心数目,有关的动力学常数和聚合速度方程(R_p=k_p[C~*][M])并着重研究了聚合物活性链性质。 在链引发阶段,发现20℃和50℃聚合,属于迅速引发类型,在0℃时则是缓慢引发类型。聚合过程中,存在明显的链转移反应。Al(i-C_4H_9)_3是主要的链转移剂。在50℃聚合时,有活性中心失活现象发生,并表明其为双基终止。 相似文献
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The homopolymerization of 5-methyl-5-hexen-2, 4-dione (methacryloylacetone, MAA),a vinyl monomer having β-diketone group, was carried out in the presence of benzophe-none (BP)/N N-dimenthyl-4-toluidine (DMT) system. Graft polymerization of acrylamideinitiated by ceric ion onto the homopolymer film was investigated and the mechanism ofthe grafting reaction was proposed on the basis of ESR study. The grafted copolymer wascharacterized by means of grafting percentage, water absorption, XPS spectra and scanningelectron photomicrographs. 相似文献
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A. A. Lysova I. A. Stenina Yu. G. Gorbunova N. A. Kononenko A. B. Yaroslavtsev 《Russian Journal of Electrochemistry》2011,47(5):579-585
Processes of aniline polymerization in perfluorinated polysulfonic acid MF-4SK solution are studied by UV-spectroscopy. Membranes
with polyaniline-modified surface layer are synthesized. It is shown by voltammetry and potentiometry that the composite materials
demonstrate asymmetric ion transfer with respect to protons and sodium cations. 相似文献
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The aqueous heterogeneous polymerization of methyl methacrylate (MMA) initiated by the Ce4+-glycolic acid (GA) redox system was studied at 35 × 0.2°C under a nitrogen atmosphere. The rate of monomer disappearance was proportional to [MMA]1[GA]1[Ce4+]°, and the rate of eerie ion disappearance was found to be directly proportional to [Ce4+] and [GA] but independent of [MMA]. The activation energy was found to be 34 kJ/mol. The molecular weight of polymethyl methacrylate increased with increasing [MMA] and decreased with increasing [oxidant]. The effect of increasing [H2SO4] on polymerization was also studied. The results are compared with those obtained for the aqueous homogeneous polymerization of acrylamide with the same redox pair. 相似文献