原子转移自由基聚合(ATRP)的研究进展

介绍了可以实现活性聚合的ATRP、RATRP、AGET ATRP和ARGET ATRP 4种原子转移自由基聚合的机理,综述了原子转移自由基聚合技术在合成两亲性嵌段共聚物、接枝聚合物和星型共聚物等中的研究进展。     

原子转移自由基聚合研究进展

原子转移自由基聚合(ATRP)反应是实现活性聚合的一种颇为有效的途径,可以合成分子量可控、分子量分布窄的各种聚合物.介绍了ATRP的研究进展,包括ATRP反应的特点、聚合反应机理、应用、研究现状及前景展望.     

水分散体系中原子转移自由基聚合研究进展

水分散体系中原子转移自由基聚合(ATRP)具有自由基聚合、乳液聚合和活性/可控聚合的优点,因此近年来关于水分散体系中ATRP的研究日益增多。本文综述了近年来水分散体系(包括乳液体系、细乳液体系、微乳液体系)中原子转移自由基聚合的研究进展,对应用在水分散体系中的几种ATRP反应机理做了简要介绍,包括正向AT-RP、反向ATRP(RATRP)、正向/反向同时进行的(SR&NI)ATRP、电子转移活化剂(AGET)ATRP,并对RATRP、SR&NI、ATRPAGET ATRP的优缺点进行了总结。     

原子转移自由基聚合合成聚丙烯酸

通过调节反应体系的pH值,利用原子转移自由基聚合(ATRP)的方法,合成了聚丙烯酸,并采用黏度法测定其相对分子质量.实验结果表明,反应体系的pH值对热反应及产物的相对分子质量有着显著影响.     

原子转移自由基聚合的研究新进展——AGET ATRP

原子转移自由基聚合(ATRP)是目前高分子化学领域的研究重点之一,AGET ATRP又是在传统ATRP基础上衍生出的一种摒弃ATRP一些缺点的新型活性/可控聚合方法。重点介绍了AGET ATRP反应的机理、引发体系、催化体系、还原剂、反应介质及反应条件,以及对AGET ATRP技术的前景与展望。     

原子转移自由基聚合在树形聚合物合成中的应用

原子转移自由基聚合(ATRP)技术是一种新型的可控/活性聚合技术,可有效地对聚合物的分子结构进行设计,制备出各种不同性能、不同组成、不同功能化的结构确定的聚合物。综述了利用ATRP技术合成树枝状-线性嵌段共聚物、类树枝状聚合物(dendrimer-like polymer)、具有刺激-响应性末端基团的树枝状聚合物、树枝状-星型嵌段共聚物和基于树枝状聚合物的聚合物刷的研究进展。     

活性自由基聚合的新进展--原子转移自由基聚合

活性自由基聚合是目前高分子科学中最为活跃的研究领域之一，原子转移自由基聚合(ATRP)反应是实现活性聚合的一种颇为有效的途径．也是高分子化学领域的最新研究进展之一。ATRP的独特之处在于使用了卤代烷作引发剂，并用过渡金属催化剂或退化转移的方式，有效地抑制了自由基双基终止的反应。ATRP可以同时适用于非极性和极性单体，可以制备多种结构形式的、结构清晰的高分子化合物。可实现众多单体的活性／可控自由基聚合。介绍了ATRP的研究进展，包括ATRP反应的特点、聚合反应机理、应用、研究现状及前景展望。     

原子转移自由基活性可控聚合进展

活性自由基聚合是目前高分子科学中最为活跃的研究领域之一,原子转移自由基聚合(ATRP)反应是实现活性聚合的一种颇为有效的途径,也是高分子化学领域的最新研究进展之一。介绍了ATRP反应的特点、聚合反应机理、应用及前景展望。     

AGET-ATRP制备三元含氟丙烯酸酯乳液及表征

用电子活化再生原子转移自由基聚合(AGET ATRP)方法,在乳液体系下合成了设定化学结构的甲基丙烯酸甲酯(MMA)-丙烯酸丁酯(BA)-甲基丙烯酸三氟乙酯(TFEMA)的三元共聚物;并通过GPC、FTIR及1H-NMR谱表征了共聚物相对分子质量和结构组成;系统研究了聚合条件对含氟丙烯酸酯共聚合物产率的影响.结果表明:含氟丙烯酸酯可以用AGET ATRP体系实现乳液体系的聚合;目标产物符合AGET ATRP的反应机理,所合成的聚合物分子结构可控且相对分子质量分布较窄(PDI=1.42).     

ATRP以及ATRP法制备嵌段共聚物研究进展综述

原子转移自由基聚合(ATRP)是合成嵌段共聚物的有效途径。本文介绍了原子转移自由基聚合(ATRP)的基本原理以及ATRP在反应体系,实验方案的研究进展,并且概述了近年来采用ATRP制备嵌段共聚物的研究进展。     

活性自由基聚合反应与多种结构聚合物的制备

介绍了原民移自由基聚合反应这一新型的活性自由基聚合方式,并综述了利用这种聚合方法制备的多种结构的聚合物,包括嵌段共取物,交替共聚物,接枝共聚物,星形聚合物,超支化聚合物,梳形聚合物等。     

引发剂在淀粉接枝反应中的研究与应用

总结了近年来淀粉与乙烯基单体接枝共聚的常用引发剂 ,对引发剂的性质、优缺点、引发机理及应用作了评述 ,引用最新文献 2 1篇。     

Expansion of core–shell PS/PMMA particles

Structured micrometric polystyrene/poly(methyl methacrylate) particles were obtained by suspension polymerization and their expansion behavior was investigated using n‐pentane as blowing agent. The expanded particles presented two distinct microstructures with an outer region (PMMA‐rich shell) composed by cells of about 10 µm while the center of the particle (PS‐rich core) had much larger cells (50–100 μm). The core–shell particles did not expand at 100°C meaning that the PMMA shell hindered the expansion of the particles. Maximum expansion was dependent on the PMMA concentration and also on the heating temperature and the increase in the PMMA molar mass led to a delay in the onset of the process. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4521–4527, 2013     

烯丙氧基聚乙氧基醚阻垢剂的合成与性能

以烯丙氧基聚乙氧基硫酸铵（APES）、马来酸酐（MA）、马来酸酐-丙烯酸共聚物（MA-AA）为原料,水为溶剂,使APES和MA、APES和MA-AA在水溶液中同时进行自由基共聚和接枝共聚,合成了APES接枝MA-AA的APES-MA聚醚型无磷的共聚物阻垢剂,用红外光谱和核磁共振氢谱对共聚物结构进行了表征。探讨了单体配比、温度和用量、黏均分子量对共聚物阻垢性能的影响,结果表明该阻垢剂既具有优异的阻Ca₃(PO₄)₂性能,又有良好的阻CaCO₃特性。温度80℃时,阻垢剂用量5 mg·L^-1,阻Ca₃(PO₄)₂率为98.89％;温度50℃时,用量5 mg·L^-1,阻Ca₃(PO₄)₂率为100.0％,用量25 mg·L^-1,阻CaCO₃率为97.97％。且CaCO₃形成易被清除的松垢,该阻垢剂适用于工业循环冷却水系统。     

Nitroxide mediated polymerization using diphenyl azabutane N-oxides. A study of electronic effects and of the [nitroxide]/[initiator] ratio on the polymerization control

3,3-dimethyl-1,1-diphenyl azabutane-N-oxides with electron-releasing and electron-withdrawing substituents in one of the aromatic rings were synthesized and their effect on styrene polymerization was assessed. Styrene polymerization kinetic experiments were carried out in bulk at 100 and 120 °C with BPO or AIBN as initiators and diphenyl-azabutane type nitroxides as mediators. Results were compared with the kinetics using the preformed alkoxyamine. Different [nitroxide]/[initiator] ratios were evaluated at 100 °C and the optimum ratio=1.75 was found. Polydispersities between 1.2 and 1.4 were obtained for polystyrene of M_n up to 25,000. Experiments to obtain molecular weights around 120,000 were also carried out using oligomeric alkoxyamines as mediators. The calculated equilibrium constant (K) of the styrene polymerization at 120 °C with diphenyl azabutane as mediator is larger than the previously reported for TEMPO 1, and similar to the reported for TIPNO 2 and DEPN 3, The polymerization with these nitroxides is faster than the polymerization using other nitroxides and substituents on the aromatic ring have no important effect on the control of polymerization; these experimental results agree with some electronic parameters obtained from molecular modeling of the nitroxides through semiempirical methods.     

PVC新型活性聚合研究进展

介绍了氯乙烯新型活性聚合以及共聚研究进展,从不同催化剂角度研究其聚合机理,为今后PVC活性聚合工艺的改进提供理论和实验依据。     

Twin screw extruders as polymerization reactors for a free radical homo polymerization

The bulk polymerization of n-butylmethacrylate was investigated in a counter-rotating twin screw extruder. It appeared that the gel effect, occurring with bulk polymerizations, affected the polymerization progress very strongly. Due to this effect the conversion of the reaction is independent of the rotation speed of the screws. The reactive extrusion diagram, presented in this paper, indicates how the different phenomena interact with each other and helps to understand the influences of extruder parameters and reaction parameters on the process.     

Effect of π-π stacking on the atom transfer radical polymerization of styrene

The atom transfer radical polymerization (ATRP) of styrene (St) was carried out in the presence of varying equivalents (eq) of hexafluorobenzene (HFB) to probe the effect of pi-pi stacking on the rate of the polymerization and the resulting tacticity of polystyrene (PSt) formed. The extent of interaction between the electron deficient face of the HFB and the electron rich face of the styrenic or polystyrenic phenyl ring was also examined as a function of reaction solvent, incorporating both non-aromatics (hexanes and THF) and aromatics (benzene and toluene). It was found that in all cases the rate of the ATRP of St was slowed by the addition of HFB to the reaction mixture, with increasing amounts of HFB (1 full eq. compared to St) retarding the rate to a relatively greater extent compared to smaller amounts (0.5 eq). Additionally, when aromatic solvents were used instead of hydrocarbons the effect of HFB on the rate of the ATRP was minimized, consistent with the solvent itself competing with the styrenic phenyl groups for pi-pi stacking interactions with HFB. The decreased rate in the presence of HFB is consistent with a reduced ability of the terminal phenyl group on the PSt chain to stabilize the active polymer radical, pushing the equilibrium further to the dormant alkyl halide. This interaction between the dormant alkyl bromide and HFB was verified by ¹H NMR, with 1-bromoethylbenzene used as the alkyl bromide. When the ATRP of non-aromatic vinyl monomers was studied (butyl acrylate and methyl methacrylate), the effect of HFB on the system was almost unnoticeable as expected due to their inability to participate in pi-pi stacking interactions. The tacticity of the PSt formed in the presence of HFB was compared to PSt formed in its absence by observing the C1 resonance on ¹³C NMR, but no change in the shape or chemical shift of the signal was observed.     

水性体系用颜料分散剂的分子量及分子量分布的控制

采用自由基聚合和稳定自由基聚合,可合成水性体系用的颜料分散剂。介绍了低聚合度、窄分子量分布的聚合物分散剂的控制方法。引发剂、链转移剂、单体的浓度、溶剂种类、反应方式、温度等诸因素对分散剂的分子量和分子量分布有很大影响。讨论了诸因素对分散剂分散性的影响。