首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 125 毫秒
1.
合成了2种固态氨酯型乙烯基醚PUE1和PUE2,并对其结构和性能进行了表征.研究发现,二芳基碘六氟磷酸盐(PI810)能引发PUE1和PUE2发生阳离子热聚合,热聚合温度远低于PI810的纯态热分解温度,且聚合转化率很高.初步认为热聚合机理是富电子的乙烯基醚双键和缺电子的二苯基碘盐阳离子之间形成中间态电荷转移复合物,降低了二苯基碘盐的热分解温度,进而生成引发活性种乙烯基醚阳离子自由基或质子酸,引发乙烯基醚的阳离子聚合反应.  相似文献   

2.
光氧化还原碘盐引发阳离子固化的研究   总被引:1,自引:0,他引:1  
合成了二苯基碘六氟磷酸盐光引发剂。研究了染料的种类和浓度对碘盐引发阳离子光固化速度的影响,用光致电子转移(光氧化还原)理论解释了这些光敏染料的光敏机理。  相似文献   

3.
光氧化还原碘Wong盐引发阳离子固化的研究   总被引:3,自引:0,他引:3  
合成了二苯基碘Wong六氟磷酸盐光引发剂。研究了染料的种类和学地磺Wong盐引发阳离子光固化速度的影响,用光致电子转移理论解释了这些光敏染料的光敏机理。  相似文献   

4.
凌华招  谢川 《合成化学》2006,14(2):170-171
以硝基苯、浓硫酸、六氟磷酸钾和碘酸钾为原料,经氧化、取代、置换反应得到3,3′-二硝基二苯基碘六氟磷酸盐(2)。2与苯硫醚在苯甲酸铜的催化下合成了3-硝基苯基二苯基硫六氟磷酸盐(3)。3是一种新型的三芳基硫鎓盐阳离子UV光引发剂,其结构经UV,1H NMR,IR及MS确证。  相似文献   

5.
镧系元素六氟磷酸盐的二苯基亚砜配合物   总被引:5,自引:0,他引:5  
有机亚砜类是镧系元素的很好的配位体.S.K.Ramalingam曾研究了镧系元素高氯酸盐的二苯基亚砜(DPhSO)配合物。我们认为合成含有非配位阴离子的配合物更便于观察亚砜与镧系元素的配位作用。从这个意义上讲六氟磷酸盐比高氯酸盐更为合适,因为已经发现,在某些镧系元素亚砜配合物中,高氯酸根与镧系元素有弱配位作用。我们合成了二苯基亚砜与镧、镨、钕、钐、镱的六氟磷酸盐配合物,其组成与文献上唯一的铕所对应的配合物组成一致。同时对配合物的红外光谱、溶液中的紫外光谱以及摩尔电导进行了测定。  相似文献   

6.
以双环戊二烯等为原料合成一种新型三官能团液体脂环族环氧树脂. 通过红外光谱、 核磁共振氢谱及质谱等对其中间体及环氧树脂的结构进行了表征. 所得脂环族环氧树脂采用阳离子引发 剂二甲苯基碘鎓六氟磷酸盐引发进行紫外光固化, 对其光固化活性进行了研究, 同时讨论了氧化剂过氧化苯甲酰对该光固化体系的增感作用. 研究结果表明, 新合成的脂环族环氧树脂采用二甲苯基碘鎓六氟磷酸盐引发可以进行光固化, 过氧化苯甲酰明显地加快了其光固化速度, 固化膜具有较好的热稳定性.  相似文献   

7.
本文报导了α,β,β-三氟苯乙烯环化二聚物的结构及其热裂解反应的研究.α,β,β-三氟苯乙烯环化二聚物全同于四氟乙烯和1,2-二氟茋的环化加成物,且其质谱中有二氟茋(分子量216)的碎片;因此证明其结构为1,2-二苯基六氟环丁烷(顺式及反式异构体的混合物),即三氟苯乙烯以头对头方式加成的产物.反式1,2-二氟芪或反式芪与四氟乙烯进行热环化加成反应,得到相应的1,2-二苯基六氟环丁烷(反式:顺式约98:2)或1,2-二苯基3,3,4,4-四氟环丁烷(反式).上述反应具有(顺,反)立体选择性.用裂解色谱法研究了1,2-二苯基六氟环丁烷的热裂解反应.在较低温度时(400°以下),主要反应是顺式物异构化为反式物的反应.在400~600°范围内,对称裂解占优势,定量地生成α,β,β-三氟苯乙烯.在高温下(700°以上)则同时有不对称裂解发生.  相似文献   

8.
以酚醛树脂(PF)为热交联物质,添加交联剂2,4,6-三[双(甲氧基甲基)氨基]-1,3,5-三嗪和产酸剂二苯基碘鎓六氟磷酸盐,表面带有精细微纳米图案的聚二甲基硅氧烷(PDMS)作为印章,采用热微接触印刷(hotμCP)技术制备热交联聚合物的微纳米图案.通过扫描电子显微镜(SEM)和接触角测量仪对精细结构图案进行表征.结果表明,这种简单、快速、低成本的hotμCP法能够成功地实现热交联聚合物的图案化,且最小尺度可接近100nm.  相似文献   

9.
成功开发出一种直接合成N-苯基苯并咪唑的新方法.在不使用金属催化剂与强碱的条件下,通过苯并咪唑与二苯基碘三氟甲磺酸盐的反应合成了目标化合物,采用1H NMR与13C NMR技术对目标化合物进行了表征,并确定了最佳反应条件.在苯并咪唑与二苯基碘三氟甲磺酸盐的物质的量比为1∶1.2、溶剂乙醇/二甲苯的体积比为1∶4、反应温度为120℃、反应时间为24h的最佳反应条件下,使目标化合物的产率达到了52.0%,并回收了等量的碘苯.此外,通过高效液相色谱技术进行跟踪监测,对该反应的机理进行了探讨.  相似文献   

10.
以P2O5为脱水剂,甲烷磺酸为溶剂,二苯亚砜与二苯硫醚反应制备了(4-苯硫基-苯基)二苯基硫六氟磷酸盐.对产物进行了元素分析、紫外光谱、红外光谱、气-质联用和核磁共振的结构确证.该硫盐对环氧树脂具有良好的固化性能.  相似文献   

11.
Formulations containing vinyl ethers and epoxy were successfully polymerized through a radical-induced cationic frontal polymerization mechanism, using an iodonium salt superacid generator with a peroxide thermal radical initiator and fumed silica as a filler. It was found that an increase of vinyl ether content resulted in higher front velocities for divinyl ethers in formulations with trimethylolpropane triglycidyl ether. However, increased hydroxymonovinyl ether either decreased the front velocity or suppressed frontal polymerization. The kinetic effects of the superacid generator and thermal radical initiator with varying vinyl ether content were also studied. It was observed that increasing concentrations of initiators increased the front velocity, with the system exhibiting higher sensitivity to the superacid generator concentration.  相似文献   

12.
Butyl vinyl ether (BVE) and methyl methacrylate (MMA) mixtures were polymerized by using free radical initiators in conjunction with a cationic initiator such as diphenyl iodonium salt. Polymerization mechanism involves free radical polymerization of MMA which is switched to cationic polymerization of BVE by addition of growing poly(MMA) radicals to BVE and subsequent oxidation of electron donating polymeric radicals to the corresponding cations by iodonium ions. Two representative bifunctional monomers, ethylene glycol divinyl ether (EGDVE) and ethylene glycol dimethacrylate (EGDMA) were also used together with MMA and BVE, respectively, in photo and thermal crosslinking polymerizations. Vinyl ether and methacrylate type monomers can successfully be copolymerized by this double-mode polymerization under photochemical conditions.  相似文献   

13.
Photoinitiated cationic polymerization of mono‐ and bifunctional epoxy monomers, namely cyclohexeneoxide (CHO), 4‐epoxycyclohexylmethyl‐3′,4′‐epoxycyclohexanecarboxylate (EEC), respectively by using sulphonium salts in the presence of hydroxylbutyl vinyl ether (HBVE) was studied. The real‐time FTIR spectroscopic, gel content determination, and thermal characterization studies revealed that both hydroxyl and vinyl ether functionalities of HBVE take part in the polymerization. During the polymerization, HBVE has the ability to react via both active chain end (ACE) and activated monomer mechanisms through its hydroxyl and vinyl ether functionalities, respectively. Thus, more efficient curing was observed with the addition of HBVE into EEC‐containing formulations. It was also demonstrated that HBVE is effective in facilitating the photoinduced crosslinking of monofunctional epoxy monomer, CHO in the absence of a conventional crosslinker. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4914–4920, 2007  相似文献   

14.
Oxoaminium salt ( 1 ), derived from 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO, 2 ) by one-electron oxidation, could be an initiator for cationic polymerization of vinyl monomers such as isobutyl vinyl ether (IBVE), 2,3-dihydrofuran, p-methoxystyrene, N-vinyl pyrrolidone, etc., to give the corresponding polymers, when 1 had a low nucleophilic counter anion. Formation of the adducts of 1 and IBVE as well as 1H-NMR and IR data suggested the formation of polymers containing N? O? C structure as the polymer head group. In the polymerization of IBVE, the effects of solvent and concentration of 1 were little observed, however the polymerization rate was dependent on temperature. Furthermore, the thermal reaction of the polymers obtained, which were regarded as prepolymers for block copolymerization and polymeric initiators for radical polymerization, was studied. For example, poly(2-benzylidene-1,3-dioxane) obtained by the polymerization of 2-benzylidene-1,3-dioxane with oxoaminium hexafluoroantimonate ( 1, X = SbF6) was employed as an initiator for radical polymerization of MMA to give its block copolymer with PMMA. © 1993 John Wiley & Sons, Inc.  相似文献   

15.
Photopolymers with unique curing capabilities were produced by combining living cationic polymerization with network formation and restricted polymer motion. A vinyl ether diol was synthesized as a functional building block and reacted with isophorone diisocyanate to form a highly functionalized vinyl ether polyurethane as a model system with high crosslinking ability. When using a cationic photoinitiator, fast polymerization is observed upon short UV irradiation. Curing proceeds in the absence of light and under ambient conditions without oxygen inhibition. Cationic active sites become trapped dormant species upon network‐induced vitrification and surprisingly remain living for several days. The polymerization can be reactivated by additional UV irradiation and/or raised temperature. The curing behavior was studied in detail by using UV and FT‐NIR coupled rheology and photo‐DSC to simultaneously study spectroscopic and mechanical information, as well as thermal effects.  相似文献   

16.
The ABA‐type triblock copolymers consisting of poly(2‐adamantyl vinyl ether) [poly(2‐AdVE)] as outer hard segments and poly(6‐acetoxyhexyl vinyl ether) [poly(AcHVE)], poly(6‐hydroxyhexyl vinyl ether) [poly(HHVE)], or poly(2‐(2‐methoxyethoxy)ethyl vinyl ether) [poly(MOEOVE)] as inner soft segments were synthesized by sequential living cationic polymerization. Despite the presence of polar functional groups such as ester, hydroxyl, and oxyethylene units in their soft segments, the block copolymers formed elastomeric films. The thermal and mechanical properties and morphology of the block copolymers showed that the two polymer segments of these triblock copolymers were segregated into microphase‐separated structure. Effect of the functional groups in the soft segments on gas permeability was investigated as one of the characteristics of the new functional thermoplastic elastomers composed solely of poly(vinyl ether) backbones. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1114–1124  相似文献   

17.
Cationic polymerization of diethyleneglycoldivinyl ether was thermally induced by diphenyliodonium, alkylbenzylsulfonium, and phenacyltetramethylenesulfonium salts. The reactivity was enhanced by using free radical sources in combination with diphenyliodonium or phenacyltetramethylenesulfonium salts. Even at low onium salt concentrations extremely reactive formulations could be obtained, e.g., the polymerization was complete within 1 minute at 100°C when using the most reactive salts. Polymerizations were induced at temperatures ranging from 50 to 180°C. The Counterion, Supplied by the onium salts, strongly influenced the appearance of the resulting crosslinked polymer: salts containing SbF6 usually gave highly discolored samples due to the large heat evolution during polymerization whereas polymerization with PF6 proceeded smoother resulting in transparent, uncolored polymers. The purity of the monomer greatly affected the initiation by the diphenyliodonium and phenacyltetramethylenesulfonium salts. Adventitious radical sources, e. g., hydroperoxides on oxidized monomer, lowered the activation temperature but also led to poor storage stability of these formulations.  相似文献   

18.
Vinyl ether polymers with imidazolium or pyridinium salt pendants underwent sensitive lower critical solution temperature (LCST)‐type phase separation in organic media. Well‐defined poly(salts) were quantitatively prepared by reaction with corresponding imidazoles or pyridines and poly(2‐chloroethyl vinyl ether), which was synthesized by living cationic polymerization. For example, a solution of the homopolymer with butyl imidazolium salts exhibited a sharp and reversible transition in chloroform upon heating. Sensitive phase separation was also observed in nonpolar solvents, such as toluene, ethyl acetate, THF, containing a small amount of a good solvent, such as 1‐butanol (10–15 wt %). The dependency of the salt structures, molecular weight, and the concentration on this behavior was demonstrated. The cleavage of the hydrogen bond is a key factor in this phase separation, as indicated by DSC and 1H‐NMR measurements. On increasing the temperature, the interaction between the polymer pendant and the solvent became weaker, hence the pendant–pendant interaction was, in turn, induced through the counter anion. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5724–5733, 2008  相似文献   

19.
Stimuli‐responsive gradient copolymers, composed of various monomers, were synthesized by living cationic polymerization in the presence of base. The monomers included thermosensitive 2‐ethoxyethyl vinyl ether (EOVE) and 2‐methoxyethyl vinyl ether (MOVE), hydrophobic isobutyl vinyl ether (IBVE) and 2‐phenoxyethyl vinyl ether (PhOVE), crystalline octadecyl vinyl ether (ODVE), and hydrophilic 2‐hydroxyethyl vinyl ether (HOVE). The synthesis of gradient copolymers was conducted using a semibatch reaction method. Living cationic polymerization of the first monomer was initiated using a conventional syringe technique, followed by an immediate and continuous addition of a second monomer using a syringe pump at regulated feed rates. This simple method permitted precise control of the sequence distribution of gradient copolymers, even for a pair of monomers with very different relative monomer reactivities. The stimuli‐responsive gradient, block and random copolymers exhibited different self‐association behavior. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6444–6454, 2008  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号