共查询到20条相似文献,搜索用时 875 毫秒
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N—[1-(2-吡咯烷酮基)甲基]丙烯酰胺类的聚合及其水凝胶于淑艳,李福绵(北京大学化学系,北京,100871)关键词N-[1-(2-吡咯烷酮基)甲基]丙烯酸胺、氧化-还原引发体系、超高分子量、平衡吸水率N一【l一(2一毗咯烷酮基)甲基]丙烯酸胺(P... 相似文献
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乙烯基单体/N—聚代马来酰亚胺共聚合动力学 总被引:4,自引:4,他引:0
详细研究了聚合温度,引发剂用量,单体配比对苯乙烯(St)/N-苯基马亚酰亚胺共聚合动力学的影响。对St、甲基丙烯酸甲酯和丙烯腈等单一或混合单体与PMI、N-环己基马来酰亚胺和N-邻氯苯基马亚酰胺的共聚合进行了研究,并讨论了单体结构的影响。 相似文献
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芳香叔胺引发丙烯腈光聚合的引发机理 总被引:1,自引:0,他引:1
芳香叔胺引发丙烯腈(AN)光聚合是通过形成激基复合物(exciPlex)进行的。紫外光谱和荧光光谱表明,芳香叔胺在基态可以和AN形成电荷转移复合物(CTC),而在激发态可和AN形成exciplc(称定域激发)。CTC经光照亦可激发(称CTC激发)。 定域激发引起光聚合速率为CH_3C_6H_4N(CH_3)_2>C_6H_5N(CH_3)_2>HOCH_2·C_6H_4N(CH_3)_2>CH_3C_6H_4N(CH_2CH_2OH)_2,与芳胺荧光被AN淬灭的Stern-Vo-lmer常数顺序一致。CTC激发引起的光聚合顺序为:CH_3C_6H_4N(CH_3)_2>CH_3C_6H_4N(CH_2CH_2OH)_2>HOCH_2C_6H_4N(CH_3)_2>C_6H_5N(CH_3)_2,与芳胺上取代基推电子能力一致。端基分析表明聚合物有芳胺端基。 相似文献
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Guo Zhang Xu Jian Hua Dong Kun Yuan Qiu 《Journal of polymer science. Part A, Polymer chemistry》1997,35(4):643-650
Several N-phenyl maleimides with different p-substituents have been synthesized from the maleic anhydride and relevant aromatic amine. In the presence of N,N-dimethyl-4-toluidine (DMT), the N-substituted phenyl maleimide (4-XPhMIs) could be polymerized under UV irradiation. It was observed that a new absorption appeared on the UV-Vis spectrum of the mixture solution of 4-XPhMI and DMT, which reveals the formation of charge-transfer complex in the ground state. It was found that the fluorescence of DMT was quenched by 4-XPhMI and the quenching constant of 4-XPhMI, obtained from the Stern–Volmer plot, increases with the electron-deficiency of ethylene double bond of 4-XPhMI. The dynamic quenching of the fluorescence of DMT by 4-XPhMI suggests the formation of exciplex in excited state between DMT and 4-XPhMI. The radicals formed in the systems have been detected by spin-trapping techniques and electron paramagnetic resonance (EPR) spectrometer. Based on all of these results, it has been proposed that the initiation process of the polymerization involves the formation of exciplex and the initial radicals were produced by proton-transfer in the exciplex from DMT to 4-XPhMI. © 1997 John Wiley & Sons, Inc. 相似文献
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C_(60)与含受电子生色基团聚合物的电荷转移现象 总被引:2,自引:0,他引:2
C60与含受电子生色基团聚合物的电荷转移现象邱健姚光庆周锡煌李福绵(北京大学化学与分子工程学院北京100871)关键词C60,聚[N (4 氰基苯基)丙烯酰胺],电荷转移现象,荧光光谱随着对球壳烯性质的深入认识,球壳烯与电子给、受体的电荷转移现象日... 相似文献
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A vinyl monomer having an electron-donating moiety, p-(N,N-dimethylamino)styrenc (DMAS),was synthesized. It was combined with benzoyl peroxide (BPO) to form a redox initiation system to initiatethe polymerization of methyl methacrylate (MMA). UV spectra measurements show that DMAS enters thePMMA chain as well. Both DMAS and its polymer P(DMAS) display strong fluorescence, and thefluorescence can be quenched by electron-deficient compounds such as methacrylonitrile, fumaronitrile andmethyl methacrylate etc. Moreover, DMAS can also form charge transfer complex (CTC) with strongelectron acceptors such as tetracyanoethylene (TCNE). The difference between the photochemical propertiesof DMAS and P(DMAS) were explained in terms of molecular structure change and polymer conformationeffect in solution. In addition, the CTC and exciplex formation of DMAS or P(DMAS) with C_(60) were alsostudied. 相似文献
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N-(p-methylphenyl) maleimide (PMPMI) was synthesized from the reaction of maleic anhydride with p-methylaniline via two steps processes. Radical polymerization of PMPMI using AIBN as an initiator or initiated with N,N-dimethyl-p-toluidine (DMT) under UV light irradiation have been investigated. Copolymerizations of methyl acrylate (MA), methyl me-thacrylate (MMA) with PMPMI were carried out in THF and cyclohexanone respectively. It was found that the molecular weights of the polymers and copolymers obtained from the cyclo hexanone were always greater than that of from THF. The monomer reactivity ratios were cal-culated. 相似文献
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N-烷基与N-芳基马来酰亚胺,是属于1,2-二取代乙烯结构的单体,文献[1—3]报道这类单体能进行自由基聚合与共聚合。但对于N-(对甲苯基)马来酰亚胺(PMPMI)的自由基聚合与共聚合中,溶剂对聚合物分子量的影响尚未有详细报道。至于N-烷基与N-芳基马来酰亚胺分别和丙烯酸甲酯(MA)、甲基丙烯酸甲酯(MMA)的共聚合也有一些报道,由竞聚率的测定,计算出N-芳基马来酰亚胶的e值是2.12—2.29和1.35—1.75。表明N-芳基马来酰亚胺是一缺电子的单体,即负性单体。我们研究室曾报道N,N-二甲基-对甲苯胺(DMT)和其它芳胺能光诱导引发负性单体丙烯腈聚合。PMP- 相似文献
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含氮给体结构对丙烯腈电荷转移光聚合的影响 总被引:1,自引:0,他引:1
<正> 对于正性烯类单体,主要是乙烯基咔唑的电荷转移聚合,诚田已作过详细综述。负性烯类单体的电荷转移聚合主要研究的单体是丙烯腈(AN)及甲基丙烯酸甲酯(MMA)。Barton等研究了芳烃为引发剂的MMA光聚合。我们研究了芳胺为引发剂的光聚合。 芳胺,尤其是芳叔胺,是较强的电子给体,与负性单体在光照下经激基复合物而引发聚合,我们的实验表明,吡啶及其同系物(喹啉与吖啶)并不象吡咯及其同系物(吲哚与咔唑)那样有效地引发AN等负性单体的光聚合(见表1)。从图1所示的结构看,它们有 相似文献
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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。 相似文献