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1.
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。  相似文献   

2.
有机过氧化物与N-甲基-N-2-羟乙基苯胺引发体系的研究   总被引:6,自引:1,他引:6  
 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。  相似文献   

3.
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   

4.
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。  相似文献   

5.
<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  相似文献   

6.
研究了BPO-胺引发体系中,不同胺对MMA聚合速度与所得聚合物色泽稳定性的影响,以及单独使用胺时对MEMA聚合的影响。实验结果表明:在前者情况下,胺对聚合反应的活性顺序为DMT≈DHET>DMA;而对聚合物的色泽稳定性也有类似的结果。从聚合速度与对色泽的要求来说,BPO-DMT与BPO-DHET是较好的引发体系。在后者的情况下,胺的活性顺序为DMT DHET>DMA>MBDMA,从聚合动力学研究可得R_p=K[DMT]~(1/2)[MEMA]_(3/2),聚合表现活化能E_a=34.3千焦耳/克分子(8.2千卡/克分子)。  相似文献   

7.
The effects of N-2-hydroxyethyl-N-methyl-p-toluidine (HMT) on MMA polymerization using organic peroxide as an initiator and on AN photoinduced polymerization have been investigated respectively. The kinetics of polymerization and the overall activation energy of polymerization were determined. Based on kinetics study and the end group analysis of the polymer obtained by UV spectrum method, the initiation mechanism is proposed.  相似文献   

8.
Two main types of amine-containing initiation systems were studied in this work. In the case of MMA polymerization initiated by BPO-amine (DMT, DHET, DMA) redox systems, it was found that the polymerization rate and colour stability of the polymer for different amine systems were in the following order: DMT≈DHET>DMA. Accordingly, BPO-DMT and BPO-DHET are effective initiators. In the case of MEMA polymerization by amine (DMT, DHET, DMA) alone, it was found that the polymerization rate and the percentage of conversion for these different amine systems were in the following order: DMT≥DHET>DMA. The polymerization rate and the percentage of conversion also increased with the increase of DMT concentration. From the kinetic investigation the rate equation of R_P=K [DMT]~(1/2) [MEMA]~(3/2) was obtained, and the overall activation energy of polymerization was calculated to be 34.3 KJ/mol (8.2 Kcal/mol). Moreover, the polymerization of MEMA in the presence of DMT was strongly inhibited by hydroquinone, indicating the polymerization being free radical in nature. From these results, the mechanism of MEMA polymerization initiated by amine was proposed.  相似文献   

9.
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.  相似文献   

10.
The initiation mechanism of acrylamide (AAM)polymerization using ceric ion/acetylacetone system as an initiator has been studied. The redox polymerization was revealed by the low value of overall activation energy of AAm polymerization. The structure of free radicals formed from above-mentioned initiation sytem were detected by radical trapping and ESR spectra techniques and the end groups of polymers obtained were determined by FT-IR spectra analysis method. Based on these results the initiation mechanism is proposed.  相似文献   

11.
The photopolymerization of acrylonitrile sensitized by N-methyl-N-(2-methacryloyloxye-thyl)aniline (MEMA) was studied kinetically. The photopolymerization rate of AN in DMF by using MEMA as sensitizer is proportional to 0.32 th power of MEMA concentration and 1.20 th power of AN concentration. The overall activation energy for the polymerization was found to be 4.82 Kcal/Mol. From the fluorescence analysis of obtained polyacrylonitrile sensitized by MEMA, it was confirmed that MEMA not only joined the inition but also entered into the polyacrylonitrile chains. The initiation mechanism was proposed tentatively.  相似文献   

12.
13.
含有芳香叔胺基的烯类单体如N,N-二甲氨基苯乙烯,N-4-N',N'-二甲氨基苯基代丙烯酰胺(DMAPAA),N-4-N',N'-二甲氨基苯基代甲基丙烯酰胺(DMAPMA),甲基丙烯酸-4-N,N-二甲氨基苄酯(DMABMA),8-丙烯酰氧喹啉(AQ)等不仅与过氧化物构成氧化还原引发体系以引发其它烯类单体的光聚合还可以作为光敏剂引发烯类单体的光聚合。由于这类功能性单体在同一分子中既含有缺电子双键基团又含有供电子生  相似文献   

14.
The radical polymerization of methyl methacrylate (MMA) was carried out with the system of imidazole (Im), copper(n) chloride, and water at 85°C. The effects of the amount of each component on the conversion of MMA were investigated. The polymerization proceeded through a radical mechanism. The overall activation energy was estimated to be 28.7 kJ/mole. The conversion of MMA showed a maximum at pH 8-9 of the aqueous solution. The formation of a complex of CuCl2 with Im, water, and MMA was confirmed by electronic spectra. An initiation mechanism was proposed.  相似文献   

15.
胺促进丙烯酸酯氧化和聚合与胺及丙烯酸酯结构有关。芳香胺氮原子或苯环上有正性取代基时,促进作用大。带醚键的丙烯酸酯氧化和聚合快。 胺引发丙烯酸酯聚合认为先是胺促进丙烯酸酯氧化,生成单体过氧化物,与胺再形成复合物,分解产生自由基,促进更多丙烯酸酯氧化,继而引起聚合。  相似文献   

16.
<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   

17.
研究了含叔胺基结构的药物奋乃静(Perphemnazinum,简称PERP)和有机过氧化物所构成的引发体系,并以此体系引发丙烯酸酯类单体聚合所得的含奋乃静缓释药膜的缓释行为.结果表明,奋乃静(PERP)和过氧化苯甲酰(BPO)引发体系引发甲基丙烯酸甲酯(MMA)聚合的动力学方程为:Rp=Kp[BPO]05[PERP]05[MMA]10,聚合表观活化能Ea=418KJ/mol,从而确定此引发体系的引发机理为氧化还原引发机理.PERP BPO体系能在40℃温度下,引发丙烯酸酯类单体共聚,而能形成含有奋乃静的缓释药膜  相似文献   

18.
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   

19.
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   

20.
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.  相似文献   

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