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1.
反应介质对N,N-二乙基二硫代氨基甲酸苄酯引发丙烯酰胺聚合反应的影响杨文君,沈家骢(青岛化工学院橡塑工程研究所,青岛,266042)(吉林大学化学系)关键词聚丙烯酰胺,溶剂效应,自由基聚合,引发-转移-终止剂近年来,具有结构的有机硫化物以其优良的In...  相似文献   

2.
N-甲基丙烯酰-N'-嘧啶哌嗪与过硫酸钾引发体系引发的丙烯酰胺聚合高青雨,张福莲,杨更须,张举贤(河南大学化学化工系,开封,475001)李福绵(北京大学化学系,北京,1000871)关键词N-甲基丙烯酰-N'-嘧啶哌嗪,可聚合芳香叔胺,氧化还原引发...  相似文献   

3.
γ-甲基-δ-酮己酸,γ-异丙基-δ-酮己酸在碘化N-甲基-2-氯吡啶盐存在下分别同(R)-四氢噻唑-2-硫酮-4-羧酸乙酯反应,得到光学活性的(R)-N-(γ-甲基-δ-酮己酰基)四氢噻唑-2-硫酮-4-羧酸乙酯(1a)及光学活性的(R)-N-(γ-异丙基-δ-酮己酰基)四氢噻唑-2-硫酮-4-羧酸乙酯(1b)。1a,1b分别同(R,S)-α-苯乙胺反应得到光学活性的酰胺2a,2b,同时使(R,S)-α-苯乙胺拆分,得到光学活性的α-苯乙胺。  相似文献   

4.
合成了新配体1-N-(苯并咪唑-1-乙酰基)-4-苯基-3-氨基硫脲(BPMS),将其与Mn(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、Cu(Ⅱ)、Cd(Ⅱ)、Zn(Ⅱ)、UO2(Ⅱ)等金属的醋酸盐反应,合成了7个新配合物。所有化合物均经元素分析、IR、1HNMR和热重分析等表征。红外光谱表明,配体以四齿方式通过烯醇式羰基氧原子、烯醇式硫羰基硫原子以及C=N1和C=N2的氮原子与金属配位  相似文献   

5.
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   

6.
4,4'-偶氮二[4-氰基戊酰(对-二甲氨基)苯胺]作为引发剂的嵌段共聚物合成邱醒宇,魏峰,关宏宇,平学真(辽宁大学化学系,沈阳,110036)关键词4,4'-偶氮二[4-氰基戊酰(对-二甲氨基)苯胺],多官能团引发剂,自由基聚合70年代以来,陆续报...  相似文献   

7.
本文研究了新显色剂7-(2-羧基-4-溴-苯偶氮)-8-羟基喹啉-5-磺酸与锌的反应条件,试验结果发现在乳化剂OP存在下,酒石酸介质中新试剂与锌形成稳定配合物,其最大吸收波长为500nm,表观摩尔吸光系数为1.15×10 ̄5L·mol ̄(-1)·cm ̄(-1),Zn ̄(2+)浓度在0~8μg/mL之间符合比尔定律,方法用于茶叶中微量锌的测定结果满意。  相似文献   

8.
引发转移终止剂 (Iniferter)是最早实现活性自由基聚合的方法 ,尽管它对聚合过程控制得不是很好 ,但是可聚合单体多 ,能方便地制备接枝和嵌段共聚物 .因此 ,近 2 0年来 ,它一直是高分子合成化学领域的一个研究热点 ,许多新颖结构的引发转移终止剂被合成并用于制备端基功能化聚合物、遥爪聚合物、大分子单体以及接枝和嵌段聚合物等 .本文扼要综述了引发转移终止剂的发展 ,着重综述了我们研究组在C—C键型高活性热引发转移终止剂、新的光引发转移终止剂、可聚合光引发转移终止剂、新型多功能引发转移终止剂和大分子光引发转移终止剂 5个方面的研究进展  相似文献   

9.
铈盐-过硫酸盐复合引发淀粉与丙烯酰胺接枝共聚合产物研究王玉芹,杨巍,崔丹(黑龙江商学院石油系哈尔滨150076)(黑龙江大学化学系哈尔滨150080)关键词Ce~(4+)-SO_2O_8~(2-)复合引发,Ce~(4+)-Ce~(3+)循环引发,淀粉与丙烯...  相似文献   

10.
在pH4.8的HAc-NH_(4)Ac介质中,Cd(Ⅱ)与1-苯基-3-甲基-4-苯甲酰基-吡唑啉酮-5(PMBP)生成配合物,于-0.67V(vs.SCE)出现一尖锐、灵敏的极谱波。镉含量在0.001~1.μg/mL范围内与峰高成线性关系。用多种电化学方法研究了极谱波的性质及电极反应机理,证明-0.67V处的极谱波为配合物吸附波,峰电流由中心离子Cd(Ⅱ)还原产生。配合物组成为Cd(Ⅱ):PMBP=1:1。试验了30多种离子对峰电流的影响,用SrSO_4共沉淀分离Pb(Ⅱ),再经巯基棉分离其它干扰离子。用于矿样中镉的测定,结果满意。  相似文献   

11.
大分子引发-转移-终止剂   总被引:2,自引:0,他引:2  
Polystyrene and polyacrylamide prepared by BDC (benzyl diethldithiocarbamate )could be ed as macromolecular iniferter and they initated styrene or acrylamidepolymerization further. The results shoWed that chain enlargement reaction inhomogeneous systems had the character of living radical polymerization and theprodusts still contained iniferter functional groups. Polystyrene macromoleculariniferter can initiate acrylamide polymerizahon in dioxane and thepolystyrene-- block-- polyanylamide copolymers were obtained. Blocking efficiency and polymerization activity were high.  相似文献   

12.
In this letter, iniferter polymerization was employed to prepare polymer dispersed liquid crystal (PDLC) films. Polystyrene (PS) was prepared as a macro-iniferter (MI). With the addition of MI in PDLC films, poly(methyl acrylate)-b-polystyrene was prepared in situ and used as polymer matrix in photopolymerization induced phase separation (PIPS). A reduction in driving voltages and an improvement in the ON state transmittance were observed for the sample prepared with a small amount of MI; while a poor electro-optical performance was obtained for that without any MI. Moreover, molecular weight and refractive index of the polymer matrix could be easily adjusted by the concentration of MI, and the matrix seems to be a prospective material for the PDLC devices.  相似文献   

13.
Polymerization of methyl acrylate (MA) with benzyl N, N-diethyldithiocarbamate (BDC) was carried out in bulk or in benzene under UV irradiation. The polymerization proceeded to give a high yield of polymer, however it was found that BDC did not function as an iniferter in the MA polymerization. Bimolecular termination leading to deactivation of the iniferter site was observed during the polymerization in preference to chain transfer and primary radical termination which reproduce the iniferter site. The deactivation was successfully prevented by combining BDC and tetraethylthiuram disulfide (TD) as a two-component iniferter. This two-component iniferter system was also applied to synthesis of a star polymer with 1,2,4,5-tetrakis (N,N-diethyldithocarbamylmethyl) benzene (DDC) as a tetrafunctional photoiniferter. © 1994 John Wiley & Sons, Inc.  相似文献   

14.
On the basis of a rather general scheme of elementary reactions of radical polymerization conducted in the presence of iniferters, kinetic equations have been derived describing this process over the whole range of monomer conversion. Proceeding from thorough analysis of these equations, different regimes of polymerization have been found that differ in values of order with respect to the iniferter and monomer of the initial rate of polymerization. Conditions for kinetic parameters have been formulated whose fulfillment predetermines that radical polymerization occurs according to the iniferter mechanism. © 1994 John Wiley & Sons. Inc.  相似文献   

15.
Styrene/N-cyclohexylmaleimide copolymers with small polydispersities and controlled molecular weights were synthesized by a free radical copolymerization using an iniferter system consisting of benzoyl peroxide and 2,2,6,6-tetramethylpiperidine-N-oxyl. Due to the interactions of the electropositive (styrene) and electronegative (N-cyclohexylmaleimide) monomers the brutto polymerization rates are higher than for other living polymerizations initiated with the same iniferter system. The prepared copolymers were used as macroiniferters for bulk polymerization of styrene.  相似文献   

16.
以不同结构的含氯化合物与铜试剂反应合成了4种链引发-转移-终止剂(Iniferter)。研究了它们引发苯乙烯的聚合反应过程,重点考察了Iniferter结构对聚合产物的影响。采用核磁共振氢谱和凝胶渗透色谱对聚合物分子量和分子量分布进行了测定。结果表明:Iniferter结构对聚合反应速率、分子量实测值与理论值间的对应关系及分子量分布均有明显影响,当其形成的初级自由基上带有使其稳定的基团时,引发效率就高,聚合反应速率较快,而且分子量理论值与实测值两者更接近。加入四甲基秋兰姆化二硫组成双组份Iniferter引发体系可以在一定程度上使聚合物分子量分布变窄。  相似文献   

17.
含聚异戊二烯 (PIP)链段的嵌段共聚物有着广泛的应用[1~ 3 ] ,有关它的合成、性能表征及应用方面的研究一直是学术及工业界的研究热点 .传统上 ,含有PIP链段的嵌段共聚物用活性负离子聚合的方法来合成 ,例如 :聚苯乙烯 聚异戊二烯嵌段共聚物[3 ,4 ] .这是由聚合物增长链端的特殊活性所决定的 ,采用活性负离子聚合方法 ,不但能很好地控制共聚物的分子量和分子量分布 ,而且能控制共聚物中各组分的比例 .但是 ,负离子聚合通常需在较苛刻的条件下进行 ,如低温高真空、高纯度的单体和溶剂 ,而且能用于负离子聚合的单体也有限 .相对而言 ,…  相似文献   

18.
This article describes for the first time the development of a new polymerization technique by introducing iniferter‐induced “living” radical polymerization mechanism into precipitation polymerization and its application in the molecular imprinting field. The resulting iniferter‐induced “living” radical precipitation polymerization (ILRPP) has proven to be an effective approach for generating not only narrow disperse poly(ethylene glycol dimethacrylate) microspheres but also molecularly imprinted polymer (MIP) microspheres with obvious molecular imprinting effects towards the template (a herbicide 2,4‐dichlorophenoxyacetic acid (2,4‐D)), rather fast template rebinding kinetics, and appreciable selectivity over structurally related compounds. The binding association constant Ka and apparent maximum number Nmax for the high‐affinity sites of the 2,4‐D imprinted polymer were determined by Scatchard analysis and found to be 1.18 × 104 M?1 and 4.37 μmol/g, respectively. In addition, the general applicability of ILRPP in molecular imprinting was also confirmed by the successful preparation of MIP microspheres with another template (2‐chloromandelic acid). In particular, the living nature of ILRPP makes it highly useful for the facile one‐pot synthesis of functional polymer/MIP microspheres with surface‐bound iniferter groups, which allows their direct controlled surface modification via surface‐initiated iniferter polymerization and is thus of great potential in preparing advanced polymer/MIP materials. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3217–3228, 2010  相似文献   

19.
Three controlled/living polymerization processes, namely atom transfer radical polymerization (ATRP), ring‐opening polymerization (ROP) and iniferter polymerization, and photoinduced radical coupling reaction were combined for the preparation of ABCBD‐type H‐shaped complex copolymer. First, α‐benzophenone functional polystyrene (BP‐PS) and poly(methyl methacrylate) (BP‐PMMA) were prepared independently by ATRP. The resulting polymers were irradiated to form ketyl radicals by hydrogen abstraction of the excited benzophenone moieties present at each chain end. Coupling of these radicals resulted in the formation of polystyrene‐b‐poly(methyl methacrylate) (PS‐b‐PMMA) with benzpinacole structure at the junction point possessing both hydroxyl and iniferter functionalities. ROP of ε‐caprolactone (CL) by using PS‐b‐PMMA as bifunctional initiator, in the presence of stannous octoate yielded the corresponding tetrablock copolymer, PCL‐PS‐PMMA‐PCL. Finally, the polymerization of tert‐butyl acrylate (tBA) via iniferter process gave the targeted H‐shaped block copolymer. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4601–4607  相似文献   

20.
The facile and efficient one‐pot synthesis of monodisperse, highly crosslinked, and “living” functional copolymer microspheres by the ambient temperature iniferter‐induced “living” radical precipitation polymerization (ILRPP) is described for the first time. The simple introduction of iniferter‐induced “living” radical polymerization (ILRP) mechanism into precipitation polymerization system, together with the use of ethanol solvent, allows the direct generation of such uniform functional copolymer microspheres. The polymerization parameters (including monomer loading, iniferter concentration, molar ratio of crosslinker to monovinyl comonomer, and polymerization time and scale) showed much influence on the morphologies of the resulting copolymer microspheres, thus permitting the convenient tailoring of the particle sizes by easily tuning the reaction conditions. In particular, monodisperse poly(4‐vinylpyridine‐co‐ethylene glycol dimethacrylate) microspheres were prepared by the ambient temperature ILRPP even at a high monomer loading of 18 vol %. The general applicability of the ambient temperature ILRPP was confirmed by the preparation of uniform copolymer microspheres with incorporated glycidyl methacrylate. Moreover, the “livingness” of the resulting polymer microspheres was verified by their direct grafting of hydrophilic polymer brushes via surface‐initiated ILRP. Furthermore, a “grafting from” particle growth mechanism was proposed for ILRPP, which is considerably different from the “grafting to” particle growth mechanism in the traditional precipitation polymerization. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013  相似文献   

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