苯乙烯与甲基丙烯酸含氟酯（FNEMA）嵌段共聚物的合成与表征

用原子转移自由基聚合方法合成了苯乙烯与甲基丙烯酸－２－（全氟壬烯氧基）乙酯的嵌段共聚物。结果表明，共聚物分子量的实验值与计算值接近，且具有低分散性。用红外光谱和核磁共振表征了此共聚物的结构。     

PEO-b-PS两亲性嵌段共聚物的合成与表征

以PEO-Br为大分子引发剂,CuBr/2-2’-联吡啶为催化体系,采用原子转移自由基聚合(ATRP)方法制得了一系列分子量可控且分子量分布窄的两亲性嵌段共聚物,通过1H-NMR、GPC、DSC等测试手段对其进行了表征,研究结果表明嵌段共聚物随着聚氧乙烯含量的降低,结晶度(Xc)、结晶熔融温度(Tm)、结晶温度(Tc)降低;当共聚物中聚氧乙烯的含量降为45%时,嵌段共聚物已无结晶现象。     

PS-b-PEA嵌段共聚物的合成与表征

采用“活性”自由基聚合的方法合成了不同分子量的苯乙烯和甲基丙烯酸乙酯[polystyrene-block-poly(ethyl methacrylate),PS-b-PEA]嵌段共聚物。并用凝胶渗透色谱(GPC)和红外光谱(FTIR)对所合成的共聚物进行了表征,实验结果显示:在4-羟基-2,2,6,6-四甲基哌啶-1-氧化物自由基(HTEMPO.)和偶氮二异丁腈(AIBN)存在下,苯乙烯聚合反应所得到的聚苯乙烯分子量分布在1.18~1.2范围,分子量随聚合时间的延长而增大(7 200~69 300 g/mol);将该聚苯乙烯溶于甲基丙烯酸乙酯,在(130±2)℃时可以重新引发甲基丙烯酸乙酯的聚合反应,且甲基丙烯酸乙酯的聚合反应具有“活性”聚合的特征,共聚物的数均分子量及分布分别在57 800~107 800 g/mol和1.22~1.26范围,共聚物由FTIR表征显示:在聚苯乙烯接上聚甲基丙烯酸乙酯后,在1 158 cm-1及1 727 cm-1出现其甲基丙烯酸乙酯的特征吸收峰,说明共聚物为嵌段共聚物。     

活性正离子聚合向活性自由基聚合转化法合成嵌段共聚物

通过枯基氯／四氯化钛／吡啶／异戊二烯活性正离子聚合反应体系制备了末端是叔氯基的聚异丁烯,经过脱氯化氢反应其分子链末端转化成异丁烯基．在9-硼二环[3,3．1]壬烷、氧气存在下引发苯乙烯的活性自由基聚合,成功地合成了异丁烯-苯乙烯嵌段共聚物,并用核磁共振仪对所得产物进行了表征。     

用原子转移自由基聚合制备苯乙烯／丙烯酸丁酯／苯乙烯三嵌段共聚物

利用原子转移自由基聚合,以α,α′－二氯对二甲苯为双功能引发剂,在ＣｕＣｌ／２,２′－联吡啶配位化合物催化下,采用二段聚合法合成了苯乙烯／丙烯酸丁酯／苯乙烯三嵌段共聚物,用ＧＰＣ测定了嵌段共聚物的相对分子质量及其分布。     

苯乙苯／α—蒎烯嵌段共聚物的合成

考察了一种用大分子引发剂制备七乙烯／α－蒎烯嵌段共取物（ＰＳｔ－ｂ－Ｐα－Ｐ０的方法，其中大分子引发剂为末端含α－Ｃｌ的聚苯乙烯，由生阳郭子聚合剂制备。首选考察了α－氯代乙苯／ＳｎＣｌ４体系的α－蒎烯聚合，进而了不同条件下的ＰＳｔ－α－Ｃｌ／ＳｎＣｌ４Ｌｅ３ｗｉｓ碱）体系的α－蒎烯聚合。产物经ＧＰＣ、ＩＲ、ＨＮＭＲ等分析确定。方法可以在不同相对分子质量的聚苯乙烯嵌段上接枝聚α－蒎烯嵌段。     

聚(苯乙烯-co-丙烯腈)-b-聚苯乙烯两嵌段共聚物的合成

以CuBr／N，N，N’，N’，N'-五甲基二亚乙基三胺(简称NNN)为催化体系，研究了原子转移自由基聚合法(ATRP)PS-b-P(S-co-AN)两嵌段聚合物的合成。研究了聚合顺序对相对分子质量及其分布和嵌段效率的影响，并且用聚合物末端C—Br键的断裂能对实验结果进行了初步解释。     

大分子自组装-嵌段共聚物的研究进展

简述了嵌段共聚物的几种合成方法,着重介绍了ATRP,RAFT两种可控活性自由基聚合,阐述了其聚合原理,以及最新的研究进展。     

两亲性聚乙烯醇-b-聚苯乙烯嵌段共聚物的合成及表征

采用原子转移自由基聚合(ATRP)法合成了具有两亲性的聚乙烯醇-b-聚苯乙烯嵌段共聚物P(VA-b-St)。首先利用调聚反应制备了带三氯甲基端基的聚醋酸乙烯大分子引发剂。以联二吡啶作配体、氯化亚铜为催化剂,引发苯乙烯单体聚合,得到结构明确的P(VAc-b-St)嵌段共聚物,而后通过皂化反应将其水解,从而得到两亲性嵌段共聚物P(VA-b- St);产物采用FT-IR、1H NMR、GPC等方法进行结构表征。P(VA-b-St)在不同浓度溶剂中的自组装行为用TEM进行了观察,结果表明:P(VA-b-St)可在DMF溶剂中形成球状囊泡结构,其尺寸达到纳米级。     

Syndiospecific styrene polymerization with CpTiCl3/MAO: Effects of the order of reactant addition on polymerization and polymer properties

Syndiospecific styrene (St) polymerization, catalyzed by the CpTiCl₃/methylaluminoxane (MAO) system, was investigated using two different activation procedures. The polymerization parameters included polymerization time, temperature (～25–100°C), ratio of [Al]/[Ti] (～100–1000), and catalyst precursor concentration (～0.5–10.0 × 10^?4 mol Ti/L). It was found that adding reactants in the order of (CpTiCl₃ + MAO) + St (Injection of Styrene mode) gave much higher monomer conversion rates, higher weight‐average molecular weights, and narrower molecular weight distributions than for the (St + MAO) + CpTiCl₃ (Injection of Catalyst mode). The former also yielded significantly higher syndiotacticity fractions. Differential scanning calorimetry measurements showed multiple peaks exhibiting polymorphism in crystalline syndiotactic polystyrene samples. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1449–1455, 2004     

功能化离子液体[C3SO3Hnhm]HSO4催化合成苯并氧杂蒽

无溶剂下以功能化酸性离子液体4-(3-磺丙基)吗啡啉硫酸氢盐([C3SO3Hnhm]HSO4)为催化剂,催化β-萘酚和芳香醛合成苯并氧杂蒽。通过单因素试验和正交试验优化反应条件,并考察了该离子液体的重复使用性能。结果表明,当苯甲醛用量为0.005 mol,β-萘酚与苯甲醛摩尔比为2∶1,催化剂用量为苯甲醛的6%,100 ℃下反应10 min后苯并氧杂蒽的产率达到91%以上。[C3SO3Hnhm]HSO4催化剂重复使用5次,其催化活性下降不明显,为苯并氧杂蒽类化合物的绿色合成提供了一种新方法。     

Synthesis of well‐defined comblike hydroxy‐functionalized atactic polystyrene promoted by metallocene/tin/poly(phenyl glycidyl ether)‐co‐formaldehyde

Well‐defined comblike atactic polystyrene functionalized with hydroxyl groups was synthesized via living/controlling radical polymerization promoted by metallocene complexes in the presence of poly(phenyl glycidyl ether)‐co‐formaldehyde as the initiator and Sn as a reducing agent. The effect of the polymerization conditions, such as the ratio of initiator to monomer, temperature, and polymerization time, and the structure of the metallocene complex on the polymerization process were investigated. The resulting polymers were characterized by gel permeation chromatography, multiangle laser light scattering, ¹H‐NMR, and ¹³C‐NMR. The results show that the polymer had a narrow molecular weight distribution in the range 1.1–1.4 and the number‐average molecular weight of the polymer linearly depended on the monomer conversion within the polymerization timescale, which confirmed that living radical polymerization characteristics prevailed in the polymerization process. Both the number of arms and the number of hydroxyl groups in each polymer molecule were about four, which suggested that they arose from the epoxy functional groups of the initiator. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Synthesis of aromatic carboxyl functionalized polymers by atom transfer radical polymerization

The synthesis of aromatic carboxyl functionalized polymers by atom transfer radical polymerization is described. The α‐bromo‐p‐toluic acid ( 1 ) initiated polymerization of styrene in the presence of copper(I) bromide and 2,2′‐bipyridyl affords quantitative yields of the corresponding aromatic carboxyl functionalized polystyrene ( 2 ). Polymerization proceeded via a controlled free radical process to afford quantitative yields of the corresponding aromatic carboxyl functionalized polymers with predictable molecular weights (M_n = 1600–25 900 g mol⁻¹), narrow molecular weight distribution (M_w /M_n = 1.1–1.40) and an initiator efficiency above 0.87. The polymerization process was monitored by gas chromatographic analysis. The functionalized polymers were characterized by thin layer chromatography, size exclusion chromatography, spectroscopy, potentiometry and elemental analysis. © 2000 Society of Chemical Industry     

茂金属化合物催化极性烯类单体活性聚合的研究进展

综述了CGC催化剂、单茂催化剂、多核茂金属催化剂、桥联茂金属催化剂,非茂金属催化剂催化极性烯类单体均聚合及极性烯类单体与非极性烯类单体共聚合的研究.茂金属催化剂催化极性烯类单体聚合的机理包括配位聚合机理与活性自由基聚合机理.采用茂金属催化体系可以制备极性烯类单体的均聚物及极性烯类单体与非极性烯类单体的共聚物.不仅拓宽了茂金属催化剂的应用范围,而且可开发出具有新性能的极性聚烯烃树脂.     

Study of ethylene polymerization catalyzed by nBu-Cp2ZrCl2/MAO catalytic system and their polymerization kinetics

Polyethylene was prepared by using a nBu-Cp₂ZrCl₂/MAO catalytic system. Considering the reactivation of Zr species, a novel and reasonable mathematical model of kinetics has been developed and the kinetic profiles of ethylene polymerization have been fitted satisfactorily. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3186–3189, 2001     

ATRP of acrylonitrile catalyzed by FeCl2/succinic acid under microwave irradiation

A single‐pot atom‐transfer radical polymerization (ATRP) under microwave irradiation was first used to successfully synthesize polyacrylonitrile. This was achieved by using FeCl₂/succinic acid as the catalyst and 2‐chloropropionitrile as the initiator. Using the same experimental conditions, the apparent rate constant under microwave irradiation was found to be higher than that under conventional heating. The FeCl₂/succinic acid ratio of 1 : 2 not only gives the best control of molecular weight and its distribution but also provides rather rapid reaction rate. When FeCl₂ was replaced with CuCl, ATRP of AN does not show an obvious living characteristics. To demonstrate the active nature of the polymer chain end, the polymers were used as macroinitiators to proceed the chain‐extension polymerization. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1598–1601, 2006     

Synthesis of methacrylic acid-styrene block copolymers by living radical polymerization in the presence of chitosan

The existence of living growing end radicals in the radical polymerization of sodium methacrylate (MAA·Na) in the presence of chitosan acetate salt has been ascertained by preparing block copolymers with styrene as secondary comonomer. When polymerization of MAA·Na eventually reached 93.4% conversion after 144 h at 30°C, secondary comonomer styrene added to the system undergoes further polymerization. Solvent extraction was performed to separate the homopolymers and block copolymers in order to determine the properties of the product. The results of the solubilities, of gel permeation chromatography and of ¹H nuclear magnetic resonance showed the characteristics of the block copolymers.     

Reverse atom‐transfer radical polymerization of acrylonitrile catalyzed by FeCl3/iminodiacetic acid

FeCl₃ coordinated by iminodiacetic acid (IMA) was Changed used for the first time as the catalyst in azobisisobutyronitrile‐initiated reverse atom‐transfer radical polymerization (ATRP) of acrylonitrile (AN). An FeCl₃ to IMA ratio of 1:2 not only gave the best control of molecular weight and its distribution but also provided a rather rapid reaction rate. The effects of solvents on the polymerization of AN were also investigated. The rate of the polymerization in N,N‐dimethylformamide (DMF) was faster than in propylene carbonate or toluene. The molecular weight of polyacrylonitrile agreed reasonably well with the theoretical molecular weight in DMF. The rate of polymerization increased with increasing polymerization temperature and the apparent activation energy was calculated to be 54.8 kJ mol⁻¹. The reverse ATRP of AN did not show obvious living characteristics with CuCl₂ instead of FeCl₃. Copyright © 2005 Society of Chemical Industry     

Synthesis of symmetric H-shaped block copolymer by the combination of ATRP and living anionic polymerization

A novel fluorescent dye labeled H-shaped block copolymer, (PMMA-Fluor-PS)₂-PEO-(PS-Fluor-PMMA)₂, is synthesized by the combination of atom transfer radical polymerization (ATRP) and anionic polymerization (AP). To obtain the designated structure of the copolymer, a macroinitiator, 2,2-dichloro acetyl-PEO-2,2-dichloro acetyl (DCA-PEO-DCA), was prepared from DCAC and poly(ethylene oxide). The copolymer was characterized by ¹H NMR, GPC and fluorescence spectroscopy.