一种树枝状侧基型聚合物的合成及其溶液性质研究

本文以乙二胺、丙烯酸甲酯、丙烯酰胺为原料,通过丙烯酰胺及丙烯酸甲酯自由基聚合反应合成主链,其次通过乙二胺与丙烯酸甲酯交替发生的酰胺化反应以及迈克尔加成反应首次将树枝状侧基引入了聚丙烯酰胺类聚合物,制备了一种新型的带树枝状侧基的聚合物,并利用红外光谱进行表征,确定了最佳合成条件：反应温度30℃,反应时间24-48h,反应物摩尔比1:1。对聚合物的水溶液性质进行了评价。结果表明,合成的带树枝状侧基的聚合物的增粘、抗温、抗盐性质较合成前聚合物都有较大的提高,达到了分子结构设计的预期效果。     

含1,3,5-三嗪核结构的新型聚酰胺(PAMAM)树枝状化合物的合成

以2,4,6,三氯-1,3,5-三嗪为核(GO)与亚胺基二乙酸二乙酯进行取代反应制得具有枝化的含有酯基官能团的树枝状化合物(G0.5),然后依次与乙二胺、丙烯酸甲酯和乙二胺反应分别制得含有1,3,5-三嗪核的G1.0、G1.5和G2.0代的树枝状化合物.采用FT-IR、1HNMR、13CNMR和ESI-MS对所合成的化...     

树枝状分子的快速合成及在保湿剂和洗涤剂中的应用

以丙烯酸甲酯和乙二胺为原料,通过Michael加成和氨解重复反应合成了以乙二胺为核的0．5G～3．5G的聚酰胺——胺树枝状分子。利用提高反应温度来加快反应速度,实现了聚酰胺——胺树枝状分子的快速合成。测试了整代树枝状分子的保湿性能及半代树枝状分子的去污性能。并用红外表征对快速合成产物与低温合成产物进行了比较。     

二苯胺基甲烷为核的树枝状高分子聚合物的合成与表征

合成了二苯胺基甲烷并作为核心材料,采用发散法合成了6种不同支化代的树枝状高分子聚合物。得到各支化代产物的较佳工艺条件为:n(二苯胺基甲烷)∶n(丙烯酸甲酯)=1∶8,于35℃下反应15 h,得到产率最高可达97.8%的0.5 G产物;n(0.5 G产物)∶n(二苯胺基甲烷)=1∶16,于25℃下反应24 h,得到产率最高可达92.0%的1.0 G产物;n(1.0 G产物)∶n(丙烯酸甲酯)=1∶16,于10℃下反应35 h,得到产率为90.7%的1.5 G产物;n(1.5 G产物)∶n(二苯胺基甲烷)=1∶16,于20℃下反应48 h,得到产率为93.7%的2.0 G产物;n(2.0 G产物)∶n(丙烯酸甲酯)=1∶32,于10℃下反应35 h,得到产率为89.7%的2.5 G产物;n(2.5 G产物)∶n(二苯胺基甲烷)=1∶32,于20℃下反应48 h,得到产率为91.0%的3.0 G产物。用IR和GC-MS对合成的二苯胺基甲烷进行结构表征。各支化代树枝状高分子聚合物的结构用IR、分子质量测定、电位滴定和扫描电镜进行表征和分析。结果表明所合成产物的结构与设计结构基本相符合。     

含偶氮侧链聚酰胺酸合成及其三阶非线性光学性能

选取苯代三聚氰胺(BGA)和均苯四酸二酐(PMDA)为单体进行微波辐射溶液聚合反应,所得聚酰胺酸(PAA)通过重氮偶合反应引入含偶氮键的侧链,并且通过二次偶合进一步增加偶氮侧链的长度,从而合成新的具有三阶非线性光学活性的侧链型聚合物。通过红外、紫外、元素分析、拉曼等测试方法对接枝聚合物的结构进行了表征。通过简并四波混频飞秒激光系统对各个接枝聚合物的三阶非线性极化率系数进行了测定,考察了含取代基的偶氮侧链的引入对聚合物主链三阶非线性的影响,并考察了侧链上偶氮键的共轭长度对主链三阶非线性的影响。结果表明,侧链上偶氮基团的引入及其长度对提高聚合物主链三阶非线性都具有一定的影响。     

氨为核树状大分子聚酰胺-胺的制备与破乳性能

采用发散法以氨为核、甲醇为溶剂,交替与丙烯酸甲酯和乙二胺反应,合成了0．5-3．0代的树枝状大分子聚酰胺-胺,采用端基滴定分析对分子的结构进行了表征,并研究了它们对模拟原油乳液的破乳性能。结果表明：它们与以乙二胺为核心的树枝状大分子聚酰胺-胺所表现出来的趋势完全一致。     

改性胍胶水煤浆分散剂的制备与性能表征

以胍胶为主剂,经过氧化还原反应后在分子链上引入含有羧基的丙烯酸、含有磺酸基的2-丙烯酰胺-2-甲基丙磺酸(AMPS)和丙烯酰胺分子单体,通过自由基缩合反应合成出改性胍胶聚合物分散剂,通过红外光谱、热分析仪、流变仪及激光粒度仪对合成产物及水煤浆体系进行测试,改性胍胶聚合物分散剂在280℃开始逐级分解,热稳定性较好;在分散剂加量为0.4%,制浆浓度为64%时,水煤浆体系的表观粘度为760 m Pa·s,水煤浆析水量较少、体系稳定。     

树状桥联亚胺基吡啶-2-甲醛配体的合成与红外表征

以乙二胺和丙烯酸甲酯为原料,通过Michael加成和酰胺化缩合反应分别合成了0.5代聚酰胺-胺树状大分子PAMAM-Me和1.0代聚酰胺-胺树状大分子PAMAM-NH2,再利用PAMAM-NH2的端基与吡啶-2-甲醛进行希夫碱反应,制备了一种新型树枝状桥联亚胺基吡啶-2-甲醛配体,产率达到95%以上。作者还讨论了新型配体的合成及分离工艺条件,最后采用红外光谱法对配体的分子结构进行了表征。     

聚酰胺-胺型树枝状分子的合成及其荧光性质

以丙烯酸甲酯和乙二胺为原料通过Michael加成和酯氨解重复反应合成了以乙二胺为核的0.5～4.0G的半代和整代聚酰胺-胺树枝状分子。并用红外、紫外、荧光等对合成产物进行了表征。     

聚氧乙烯基型降滤失剂SJ-1的合成与性能评价

采用2-丙烯酰胺基-2-甲基丙磺酸(AMPS)、丙烯酰胺(AM)与具有大分子侧链聚氧乙烯基(C2H4O)n的烯丙基聚氧乙烯醚(APEG)三元共聚得到钻井液用降滤失剂SJ-1,并对其进行了性能评价。通过单因素实验优化得到最佳合成方案为:单体质量分数为15%,反应温度控制在60℃,引发剂质量分数为0.2%,n(AM)∶n(AMPS)∶n(APEG)=14∶5∶1。通过红外光谱表征可知,所合成的聚合物结构和预计的结构一致。性能评价表明,所合成的聚合物具有较好的抗温能力(200℃),在盐质量分数为30%的盐水泥浆中仍具有较好的降失水能力。     

单组分多用途新型厌氧胶的研制

以甲基丙烯酸甲酯(MMA)和N,N-二甲基乙二胺(DMEDA)为主要原料、二月桂酸二丁基锡为催化剂,合成了一种新型功能单体甲基丙烯酰胺乙基二甲基胺(MAEDA)。通过单因素试验和正交试验优选出MAEDA合成的最佳条件,并采用红外光谱(FT-IR)、核磁共振(1H-NMR、13C-NMR)光谱和元素分析等手段对产物结构进行了表征。研究结果表明:合成MAEDA的最佳条件为n(MMA)∶n(DMEDA)=2∶1,w(二月桂酸二丁基锡)=2%(相对于总料液而言),95~100℃反应4h;在最佳合成条件下,MAEDA的收率可达到94%以上。在传统厌氧胶配方中,加入w(MAEDA)=5.0%(相对于厌氧胶而言),制取的新型单组分厌氧胶对铜、铁、铝、锌、不锈钢和非金属等材质均具有较快的固化速率和良好的粘接性能,并且稳定性良好。     

Thiophenols as chain transfer agents in the polymerization of vinyl monomers

The behaviour of a series of 4-substituted thiophenols as chain transfers in the photopolymerization of the acrylamide and methyl methacrylate was studied. The addition of concentrations lower than 1 mM of thiophenols to the polymerization of acrylamide in aqueous solutions reduces slightly the polymerization rate but decreases markedly the polymer molecular weight. Chain transfer constants were determined by a modified Mayo equation that consider the variation of the polymerization rate with the chain transfer agent. The addition of thiophenols to the polymerization of methyl methacrylate in organic media reduced considerably the polymer molecular weight without variations in the polymerization rate. The chain transfer rate constants for both monomers are well correlated with the electron donor-acceptor ability of the 4-substitutents, increasing with electron donating groups. An amino substituent in the 4-position increases 10 times the chain transfer constant with respect to the unsubstituted compound. No correlations were found with reported data on stability of the thiyl radicals or the addition rate to the monomer. The electron-donating effect of 4-substituents on the chain transfer constant is related to polar structures in the transition state, and suggests that the main controlling chain transfer step by thiophenols is the H-abstraction from the S-H.     

Highly efficient synthesis of cylindrical polymer brushes with various side chains via click grafting-onto approach

Though much attention has been paid to synthesis of cylindrical polymer brushes, it is still not easy to prepare well-defined brushes by a general approach. Herein, well-defined cylindrical polymer brushes with various side chains were synthesized via grafting-onto approach by CuAAC click chemistry. Narrowly dispersed polymer backbones functionalized with azide groups were obtained by post-modification of poly(glycidyl methacrylate) (PGMA) which was prepared by reversible addition-fragmentation chain transfer (RAFT) mediated radical polymerization. The alkyne-terminated side chains, polystyrene, polyacrylates, polymethacrylates and poly(N-alkyl acrylamide)s, were synthesized by RAFT mediated radical polymerization with alkyne-containing chain transfer agents (CTAs). The CuAAC reactions between the backbone and side chain polymers were conducted with an equivalent feed of alkyne-terminated side chains and azide groups under mild conditions. Influences of reaction conditions and chemical composition of polymer side chains on grafting efficiency and molecular weight distribution of the polymer brushes were investigated. It is demonstrated that the side chains of polystyrene, polyacrylates and poly(N-alkyl acylamide)s were grafted at a density above 85% while that of polymethacrylates decreased to ca. 50%. The polymer brushes synthesized under the optimized reaction conditions had well-defined chemical composition and narrow distribution of molecular weight, and their wormlike morphology was visualized by atomic force microscopy (AFM).     

腈纶废丝改性水解物的制备及其絮凝效果

常压时在碱性条件下水解腈纶废丝可生成丙烯酰胺和丙烯酸的无规共聚物,此法在得到有机高分子絮凝剂的同时又能避免废腈纶对环境的污染。在常压、95～100℃下用乙二胺对废腈纶碱性水解物进行改性,制得含有酰胺基、羧钠基、羧基及羧铵基等活性基团的高分子絮凝剂,研究了改性水解产物对废水的絮凝性能,并由红外光谱对其结构进行了分析。结果表明,乙二胺在腈纶碱性水解过程中能够促进腈基的水解,改性水解物对废水的脱色、除浊、去油、除酚效果均明显优于水解产物,经测定其除浊、去油、除酚效果分别达到98%、70%、70%。     

四乙酰乙二胺的合成研究

以乙二胺、乙酸、乙酸酐为原料,在同一反应釜内,采用两步法合成四乙酰乙二胺。结果表明,当ｎ（乙二胺）∶ｎ（乙酸）∶ｎ（乙酸酐）＝１∶２５∶４,反应温度为１２０℃（第一步）和１４０℃（第二步）,反应时间为９～１０ｈ时,产品产率可达７５％。     

Preparation of a crosslinked polyelectrolyte membrane for fuel cells with an allyl methacrylate based two‐step reaction

In this study, a proton‐exchange membrane for fuel cells was prepared via a two‐step reaction with an allyl methacrylate (AMA) as an asymmetric crosslinking agent. First, a linear‐chain polymer was synthesized, consisting of hydrophilic 2‐acrylamido‐2‐methylpropanesulfonic acid (AMPS), hydrophobic 2,2,2‐trifluoroethyl methacrylate (TFEMA), and AMA. Subsequently, we crosslinked the linear‐chain polymer by reacting the remaining allyl group during dry heating. The proton conductivity of the prepared membrane was 7 × 10^?2 S/cm at room temperature. The membrane was characterized by Fourier transform infrared spectroscopy, differential scanning calorimetry, and atomic force microscopy. The polymer electrolyte membrane fuel cell (PEMFC) performance was evaluated for a membrane electrode assembly composed of the crosslinked AMPS–TFEMA–AMA/ fluoroalkyl graft polymer (FGP) membrane. As a result of a power‐generation test, a maximum power density of 174 mW/cm² at a current density of 400 mA/cm² was observed for a PEMFC single cell. Consequently, it was confirmed that the AMPS–TFEMA–AMA/FGP membrane for PEMFC could easily be prepared via a two‐step reaction at a low cost and that PEMFC exhibited a cell performance and that of cells with the Nafion membrane. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Aqueous dispersion polymerization of acrylamide with quaternary ammonium cationic comonomer

Using aqueous solution of ammonium sulfate as medium, acrylamide (AM) and dimethylaminoethyl methacrylate methyl chloride (DMC) as main raw materials, poly(dimethylaminoethyl methacrylate methyl chloride) (PDMC) as stabilizer and 2,2′‐azobis (2‐amidinopropane) dihydrochloride (V‐50) as initiator, the cationic polyelectrolyte of P(DMC‐AM) was synthesized by aqueous dispersion polymerization. The effects of the major reaction variables on synthesis conditions, product characteristics (particle size and molecular weight), and polymerization rate were investigated. The polymerization was retarded by the presence of the ammonium sulfate. The optimum reaction conditions for obtaining a stable aqueous dispersion were concentrations of 1.8 × 10^?4–7.0 × 10^?4 mol L^?1 for V‐50, 1.5–3.5% for stabilizer, and 23.2–30.0% for salt. The molecular weight of PDMC formed was 1.5 × 10⁵ to 7.0 × 10⁵. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

N-乙基乙二胺的合成研究

以乙二胺和氯乙烷为起始原料,甲醇为溶剂,甲醇钠为缚酸剂,合成N-乙基乙二胺,通过精馏分离得到高纯度目标产物并回收甲醇和过量的乙二胺。实验优化了反应条件:乙二胺∶氯乙烷摩尔比=1.5∶1,反应温度40℃,反应时间4h,产品收率达到70.7%。通过气质联用(GC-MS)对目标产物N-乙基乙二胺进行了定性确认。     

Low protein fouling polypropylene membrane prepared by photoinduced reversible addition‐fragmentation chain transfer polymerization

In this study, 2‐hydroxyethyl methacrylate and N‐isopropyl acrylamide was block grafted onto the polypropylene macroporous membrane surface by photo‐induced reversible addition‐fragmentation chain transfer (RAFT) radical polymerization with benzyl dithiobenzoate as the RAFT agent. The degree of grafting of poly(2‐hydroxyethyl methacrylate) on the membrane surface increased with UV irradiation time and decreased with the chain transfer agent concentration increasing. The poly(2‐hydroxyethyl methacrylate)‐ grafted membranes were used as macro chain transfer agent for the further block graft copolymerization of N‐isopropyl acrylamide in the presence of free radical initiator. The degree of grafting of poly(N‐isopropyl acrylamide) increased with reaction time. Furthermore, the poly(2‐hydroxyethyl methacrylate)‐ grafted membrane with a degree of grafting of 0.48% (wt) showed the highest relative pure water flux and the best antifouling characteristics of protein dispersion. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Propagation of vinyl polymers on clay surfaces. II. Polymerization of monomers initiated by free radicals attached to clay

The adduct of Kaolin and 2,2′-azobisisobutyramidine hydrochloride has been used to initiate the polymerization of methyl methacrylate, styrene, styrene-butadiene, vinyl acetate, chloroprene, acrylamide, and acrylonitrile. Both extractable and nonextractable polymers are obtained. The adduct of bentonite and 2,2′-azobisisobutyramidine hydrochloride will initiate the polymerization of methyl methacrylate, acrylamide, vinyl acetate, 4-vinylpridine, and styrene. Both extractable and nonextractable polymers are formed. When the bentonite or the hectorite adducts are more than 99% decomposed prior to the addition of methyl methacrylate, essentially no extractable polymer is formed, but an increased quantity of nonextractable polymer is produced. This is probably due to an increased accessibility of the monomer to the clay's interior surface and a decrease in the rate of chain termination. As is the case of the kaolin adduct, the clay surface of bentonite appears to accelerate the chain growth considerably.