有机过氧化物与N,N-二(2-羟烷基)对甲苯胺体系引发烯类聚合及其机理的研究

 研究了有机过氧化物BPO,LPO分别与N,N-二(2-羟烷基)对甲苯胺DHET,DHPT组成的体系引发MMA的聚合。测定其聚合速度R_p,聚合表观活化能,聚合速度方程,聚合放热过程的温度与时间的关系。用自旋捕捉和ESR波谱技术,测定了上述体系反应产生的自由基中间体,同时通过聚合物端基分析证实DHET,DHPT组份产生的自由基能引发单体聚合。依据实验结果提出了这类体系的引发机理。     

有机过氧化物与N,N-二(2-羟烷基)对甲苯胺体系引发烯类聚合及其机理的研究

研究了有机过氧化物BPO,LPO分别与N,N-二(2-羟烷基)对甲苯胺DHET,DHPT组成的体系引发MMA的聚合。测定其聚合速度R_p,聚合表观活化能,聚合速度方程,聚合放热过程的温度与时间的关系。用自旋捕捉和ESR波谱技术,测定了上述体系反应产生的自由基中间体,同时通过聚合物端基分析证实DHET,DHPT组份产生的自由基能引发单体聚合。依据实验结果提出了这类体系的引发机理。     

含胺基功能性单体的聚合研究——Ⅲ.甲基丙烯酸4-(N,N-二甲氨基)苄酯在过氧化月桂酰引发下的聚合动力学

<正> 由芳香叔胺如N,N-二甲基对甲苯胺(DMT),N,N-二甲基苯胺(DMA)与过氧化苯甲酰(BPO)所组成的氧化还原体系以引发烯类单体的聚合已有较多报道,这种引发体系在医用高分子的硬组织材料如齿科材料,骨水泥的甲基丙烯酸甲酯(BMA)的低温快速固化上广被应用,构成这种氧化还原体系的低分子胺具有一定的毒性,其用量虽少,     

芳香叔胺引发丙烯腈光聚合研究

我们发现芳香叔胺是丙烯腈聚合极有效的光引发剂。芳香叔胺苯环上氢被正性基取代时,引发能力增加,被负性基取代时,引发能力下降。下列胺的活性次序是:N,N-二甲基对甲苯胺(DMT)>N,N-二羟乙基对甲苯胺(DHET)>N,N-二甲基苯胺(DMA)>N,N-二甲胺基苯甲醛(DMB)>N,N-二甲基对硝基苯胺(DNA)。芳香叔胺引发丙烯腈光聚合属自由基机构,聚合速度与叔胺浓度的0.66次方成正比。在叔胺浓度为10~(-2)—10~(-4)M范围内,聚合物平均聚合度的倒数与叔胺浓度的0.5次方成正比。初步认为在紫外光激发下,芳香叔胺与丙烯腈分子生成激发态电子转移络合物,再分解产生自由基,引发丙烯腈聚合。     

胺对有机过氧化物引发聚合的影响

<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:     

有机过氧化物与二元叔胺引发体系的研究

<正> 过氧化苯甲酰(BPO)引发烯类单体的聚合,可以添加芳叔胺N,N-二甲苯胺、N,N-二甲基对甲苯胺(DMT)促进BPO的分解而提高聚合速度。关于有机过氧化物与多元胺体系的研究,虽然有一些报道,但主要是多元伯胺或仲胺的体系,如异丙苯过氧化氢(CHP)与四亚乙基五胺或与二亚乙基三胺体系。本文采用BPO、LPO(过     

有机过氧化氢物与芳叔胺体系引发甲基丙烯酸甲酯聚合的研究

以有机过氧化氢物叔丁基过氧化氢(TBH)或异丙苯过氧化氢(CHP)与芳叔胺N,N-二甲基苯胺(DMA)或其衍生物组成的体系引发甲基丙烯酸甲酯(MMA)聚合。研究有机过氧化氢物与芳叔胺结构对聚合的影响,测定了TBH-胺与CHP-胺体系引发MMA聚合的总活化能分别为50-57KJ/mol与39-62KJ/mol,并对CHP-DMT(N,N-二甲基对甲苯胺)引发MMA聚合动力学以及有关引发聚合机理进行了研究。     

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

<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。     

N-甲基-N-(2-羟乙基)-对-甲苯胺存在下甲基丙烯酸甲酯的自由基聚合

测定了在N-甲基-N-(2-羟乙基)-对-甲苯胺(HMT)存在下,MMA以过氧化物引发的聚合速率和聚合表观活化能.发现HMT对BPO、LPO引发的MMA聚合有促进作用,提高聚合速率.由聚合物端基分析证实了含有HMT的碎片,表明由芳叔胺HMT与BPO反应产生的自由基能引发单体聚合,BPO-HMT引发聚合为一氧化还原引发聚合.     

过氧化二碳酸酯和N N-二羟烷基对甲苯胺体系引发甲基丙烯酸甲酯聚合

本文以过氧化二碳酸酯BPPD和芳叔胺DHET、DHPT、DMT、DMA组成的引发体系进行MMA聚合的研究。测定了聚合速率R_p,发现添加DHET、DHPT能促进MMA的聚合,缩短诱导期,提高R_p,其效果要比DMT、DMA为好。测定了E₃和聚合速率方程。由ESR谱和端基分析证实DHET、DHPT芳胺组分产生的自由基能引发单体聚合。     

STUDIES ON ORGANIC PEROXIDE/N, NDI (2-α-METHYL-ACRYLOYLOXY PROPYL)-PARA-TOLUIDINE BINARY SYSTEMS

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.     

RADICAL POLYMERIZATION OF N, N-DI(2-2''''-METHYL-ACRYLOYLOXY-PROPYL)-PARA-TOLUIDINE FUNCTIONAL MONOMER

Functional monomer (MP)_2PT having tertiary aromatic amino group was systhesized from the reaction of N, N-di (2-hydroxypropyl)-p-toluidine with 2-methyl acryloyl chloride. In the presence of organic peroxide, the radical polymerization of (MP)_2PT in toluene took place. The kinetics of (MP)_2PT polymerization and the ESR spectra of LPO-(MP)2PT-MNP systems were determined respectively.     

有机过氧化物与N-甲基-N-2-羟乙基苯胺引发体系的研究

测定了有机过氧化物与N-甲基-N-2-羟乙基苯胺(HMA)体系引发MMA聚合的动力学方程和聚合表现活化能。由过氧化物/HMA/MNP的ESR波谱证实芳叔胺HMA中,与氮原子相连的亚甲基的氢被摘去形成相应的碳自由基,它能引发单体聚合成为聚合物的端基。这也由聚合物的UV光谱所证实,由实验结果提出这类体系的引发机理。     

有机过氧化物与N-甲基-N-2-羟乙基苯胺引发体系的研究

 测定了有机过氧化物与N-甲基-N-2-羟乙基苯胺(HMA)体系引发MMA聚合的动力学方程和聚合表现活化能。由过氧化物/HMA/MNP的ESR波谱证实芳叔胺HMA中,与氮原子相连的亚甲基的氢被摘去形成相应的碳自由基,它能引发单体聚合成为聚合物的端基。这也由聚合物的UV光谱所证实,由实验结果提出这类体系的引发机理。     

Electrochemical Behavior of Ce(IV)/Ce(III) Couple in N,N-Di(2-ethylhexyl)-n-butanamide (DEHBA), N,N-Di(2-ethylhexyl)-iso-butanamide (DEHiBA), and N,N-Di(2-ethylhexyl)-3,3-dimethyl Butanamide (DEHDMBA)

In this work we report on the electrochemical behavior of Ce(IV)/Ce(III) redox couple in pure N,N-dialkyl amides (N,N-DA), namely N,N-di(2-ethylhexyl)-n-butanamide (DEHBA), N,N-di(2-ethylhexyl)-iso-butanamide (DEHiBA), and N,N-di(2-ethylhexyl)-3,3-dimethyl butanamide (DEHDMBA) equilibrated with nitric aqueous solutions as an entry to the direct electrochemical characterization of plutonium in these extractants. Ce(IV)/Ce(III) redox process was used as a model. Its potential (E_1/2≅1.02 V/SCE) is not affected by the temperature and the nature of the N,N-DA and this clearly indicates that the functionalities of these extractants produce the same relative effect on both +IV and +III oxidation states of the cerium cation. Linear variations of the current intensity of the reduction peak of Ce(IV) with the concentration of Ce(IV)/N,N-DAs/HNO₃(5 M) solutions were obtained from cyclic voltammograms recorded at 25 °C and 40 °C. Due to the poor definition of the voltammograms in DEHiBA and DEHDMBA, such characterization allows only the evaluation of the performances of the chemical extraction of Ce(IV) from aqueous nitric acid solution by the undiluted DEHBA. To our knowledge, the electrochemical behavior of Ce(IV)/Ce(III) in N,N-DAs was not previously studied and our findings will for sure open the door for further investigations in this field.     

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

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。     

吗啉类对甲基丙烯酸甲酯自由基聚合的影响

<正> 文献曾简要报道叔丁基过氧化氢(TBH)与脂环仲胺哌啶(P)体系能引发甲基丙烯酸甲酯(MMA)聚合,而TBH与脂环仲胺吗啉(MP)也可作为厌氧胶的引发体系.为了研究吗啉类化合物对有机过氧化物引发聚合的影响,本文采用四种有机过氧化物:过氧化苯甲酰(BPO)、过氧化月桂酰(LPO)、TBH、过氧化苯甲酸叔丁酯(TBPB),研     

STUDIES ON RADICAL POLYMERIZATION OF METHYL METHACRYLATE INITIATED WITH ORGANIC PEROXIDE-AMINE SYSTEMS

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.