K2TiO3催化酯交换合成甲基丙烯酸二甲氨基乙酯

以K2TiO3为催化剂,甲基丙烯酸甲酯和二甲氨基乙醇为原料催化合成了甲基丙烯酸二甲氨基乙酯,考察了影响反应的因素。实验结果表明,K2TiO3多相催化剂用于催化合成甲基丙烯酸二甲氨基乙酯,催化活性高,反应条件温和,操作方法简便。当K2TiO3用量为反应物总质量的1.0%、n(甲基丙烯酸甲酯)∶n(二甲氨基乙醇)=3∶1、反应时间6 h、反应温度98~110℃时,二甲氨基乙醇转化率为94.4%,甲基丙烯酸二甲氨基乙酯的收率为92.8%,选择性为98.3%。K2TiO3催化剂重复使用5次后,DMA的选择性仅下降3.1%。     

甲基丙烯酸-N,N-2-甲基乙胺酯原子转移自由基聚合动力学研究

A kinetic model was developed to describe the atom transfer radical polymerization (ATRP) of 2-(N,N-dimethylamino) ethyl methacrylate (DMAEMA). The model was based on a polymerization mechanism,which included the atom transfer equilibrium for primary radical, the propagation of growing polymer radical, and the atom transfer equilibrium for the growing polymer radical. An experiment was carried out to measure the conversion of monomer, the number-average molecular weight of polymer and molecular weight distribution for the ATRP process of DMAEMA. The experimental data were used to correlate the kinetic model and rate constants were obtained. The rate constants of activation and deactivation in the atom transfer equilibrium for primary radical are 1.0 x 104 L·mol-1.s-1 and 0.04 L·mol-1.s-1, respectively. The rate constant of the propagation of growing polymer radical is 8.50 L·mol-1.s-1, and the rate constants of activation and deactivation in the atom transfer equilibrium for growing polymer radical are 0.045 L.mol-1.s-1 and 1.2 × 105 L·mol-1.s- 1, respectively. The values of the rate constants represent the features of the ATRP process. The kinetic model was used to calculate the ATRP process of DMAEMA. The results show that the calculations agree well with the measurements.     

Neutral Pd(II) and Ni(II) Acetylide Initiators for Polymerization of (Dimethylamino)ethyl Methacrylate

A series of air-stable, late transition, metal-based initiators with the structures ML₂(CCR)₂ (M=Pd and Ni; L=PPh₃ and Pn-Bu₃; R=Ph and CH₂OH) for the polymerization of (dimethylamino)ethyl methylate (DMAEMA) were developed. Transition metal, phosphine, alkynyl, as well as solvents exhibited significant influence on the polymerization. Among them, Pd(CCPh)₂(PPh₃)₂ (PPP) shows the highest activity in CHCl₃ for DMAEMA polymerization. The PDMAEMA obtained is a syndiotactic polymer with high number-average molecular weight (M_n) of 20.2 × 10⁴. A free radical polymerization mechanism with some ATRP characteristics was proposed for the present polymerization.     

头孢替安中间体N,N-二甲基氨基乙基-5-巯基-四氮唑的合成研究

N,N-二甲基氨基乙基-5-巯基-四氮唑（DMMT）为合成头孢替安的关键中间体。N,N-二甲基乙二胺与CS2加成后,不经巯基保护,直接与NaN3闭环合成得到产品,总收率达到75.4%。对实验条件进行了优化。     

甲基丙烯酸2-(二乙氧基硫代磷酰氧基)乙基酯的合成及应用

以甲基丙烯酸-β-羟乙酯(HEMA)与O,O-二乙基硫代磷酰氯为原料,在三乙胺作缚酸剂,氯化亚铜(CuCl)作催化剂的条件下,合成了甲基丙烯酸2-(二乙氧基硫代磷酰氧基)乙基酯(DPTEM)阻燃剂,再与丙烯腈共聚得到了阻燃聚丙烯腈共聚物。在n(HEMA)/n(三乙胺)=1,m(CuCl)/m(HEMA)=0.01~0.02,反应温度0~5℃条件下,DPTEM的产率达82%;通过FTIR、1HNMR、MS测试技术表征了DPTEM的结构,证明产品结构正确。丙烯腈共聚物中w(DPTEM)=25%时,极限氧指数(LOI)值可达27。该工艺已通过中试,正在进行扩大化生产。     

Synthesis and pH-dependent micellization of 2-(diisopropylamino)ethyl methacrylate based amphiphilic diblock copolymers via RAFT polymerization

The polymerization of 2-(diisopropylamino)ethyl methacrylate (DPA) by RAFT mechanism in the presence of 4-cyanopentanoic acid dithiobenzoate in 1,4-dioxane was studied. The DPA homopolymer was employed as a macro chain transfer agent to synthesize pH-sensitive amphiphilic block copolymers using poly(ethylene glycol) methyl ether methacrylate (PEGMA) as the hydrophilic block. ¹H NMR and GPC measurements confirmed the successful synthesis of these copolymers. Potentiometric titrations and fluorescence experiments proved that the copolymers underwent a sharp transition from unimers to micelles at a pH of ∼6.7 in phosphate buffered saline solutions. It was found that the hydrophilic/hydrophobic balance of these block copolymers had no apparent effect on their pH-induced micellization behaviors. The DLS investigation revealed that the micelles have a mean hydrodynamic diameter below 60 nm with a narrow size distribution.     

Synthesis and Characterization of Polystyrene‐Encapsulated Laponite Composites via Miniemulsion Polymerization

Summary: A novel polystyrene‐encapsulated laponite composite system has been developed via a miniemulsion polymerization approach. The encapsulation mechanism and process parameters have been examined in detail using light‐scattering, sedimentation analysis, wide‐angle X‐ray diffraction (WXRD), and transmission electron microscopy (TEM). The laponite was encapsulated through a miniemulsion polymerization process in which laponite was predispersed in the monomer phase. The stability of both the miniemulsion and the latex depends on initiation loci, premixing procedures, intensity and time of ultrasonification and the surfactants and co‐stabilizer used. Hydrophobicity of the laponite clay played a vital role in both the encapsulation of the clay and the stability of the latex. A quaternary ammonium salt, cetyltrimethylammonium bromide (CTAB), was mixed with the clay in the monomer phase prior to emulsification. As a result, the clay particles were hydrophobically modified and were intercalated. The hydrophobicity not only favored the clay dispersion in the oil droplets but also aided the entry of the monomer into the clay's intergalleries during polymerization. Meanwhile, CTAB helped stabilize the system when it was used in conjunction with the nonionic surfactant polyoxyethylene (40) isooctylphenyl ether (TX‐405). In this way, the laponite is effectively encapsulated within a polystyrene shell in a stable latex form. More importantly, the polymerization initiated in the intergalleries of the clay effectively expands the clay's platelet array to form an exfoliated structure.

     

甲基丙烯酸二乙氨基乙酯的合成

以甲基丙烯酸和草酰氯为原料,配比为n（甲基丙烯酸）：n（草酰氯）=1：1．08,草酰氯法合成了甲基丙烯酰氯：以二乙氨基乙醇与甲基丙烯酰氯为原料,乙醚为溶剂进行酰基化反应,配比为n（甲基丙烯酰氯）：n（二乙氨基乙醇）=1：1．6,冰浴下反应4h,合成了一种用途广泛的多功能单体甲基丙烯酸二乙氨基乙酯（DEAM）,相对于甲基丙烯酰氯的收率为94．4％。     

甲基丙烯酸-N, N-2-甲基乙胺酯原子转移自由基聚合动力学研究

A kinetic model was developed to describe the atom transfer radical polymerization (ATRP) of 2-(N,N-dimethylamino) ethyl methacrylate (DMAEMA). The model was based on a polymerization mechanism, which included the atom transfer equilibrium for primary radical, the propagation of growing polymer radical, and the atom transfer equilibrium for the growing polymer radical. An experiment was carried out to measure the conversion of monomer, the number-average molecular weight of polymer and molecular weight distribution for the ATRP process of DMAEMA. The experimental data were used to correlate the kinetic model and rate constants were obtained. The rate constants of activation and deactivation in the atom transfer equilibrium for primary radical are 1.0 × 104 L·mol-1·s-1 and 0.04L·mol-1·s-1, respectively. The rate constant of the propagation of growing polymer radical is 8.50L·mol-1·s-1, and the rate constants of activation and deactivation in the atom transfer equilibrium for growing polymer radica     

两种甲基丙烯酸二甲氨乙酯基季铵盐的合成及缓蚀性能

以甲基丙烯酸二甲氨乙酯为母体,分别以氯丙烯和氯化苄为桥连基设计合成了两种季铵盐(DMA-Ⅰ和DMA-Ⅱ)。利用红外光谱、核磁共振氢谱证实所得产物与设计相一致。通过失重实验、电化学实验、AFM、接触角等手段测试了Q235钢在含有DMA-Ⅰ和DMA-Ⅱ的1mol/L盐酸中的缓蚀性能,探讨了其在Q235钢表面的吸附和缓蚀机理。结果显示:在较高温度下,DMA-Ⅰ和DMA-Ⅱ仍能牢固吸附在Q235钢表面,当所加入缓蚀剂的质量浓度为100 mg/L时,缓蚀率均可达92.7%以上,显示出良好的缓蚀性能,且DMA-Ⅰ比DMA-Ⅱ具有更好的缓蚀效果。热力学计算结果表明,DMA-Ⅰ和DMA-Ⅱ在Q235钢表面的吸附是化学吸附,过程自发、放热,且符合Langmuir等温吸附,属于良好的阳极型缓蚀剂。量子化学计算进一步研究了DMA-Ⅰ和DMA-Ⅱ的分子结构与活性位点,结果表明,DMA-Ⅰ更容易提供或接受电子。     

Reversible Addition Fragmentation Chain Transfer (RAFT) Emulsion Polymerization of Methyl Methacrylate via a Plasma-initiated Process

Summary The plasma-initiated emulsion polymerization of MMA in the presence of 2-cyanoprop-2-yl 1-dithionaphthalate (CPDN) was first investigated. The polymers were characterized by GPC, ¹H NMR, DSC and SEM. The results exhibit controlled polymerization characters: well-controlled molecular weight, relatively narrow polydispersity, molecular weight linearly increasing with conversion and successful chain extension reactions. The influence of the amount of the sodium dodecyl sulfate (SDS), CPDN concentration, plasma duration time on the polymerization rate, and micro-shape of the particle was investigated in this work. The plasma-initiation emulsion polymerization of octyl acrylate (OA) in the presence of CPDN is also carried out.     

两种甲基丙烯酸二甲氨乙酯基季铵盐的合成及缓蚀性能

以甲基丙烯酸二甲氨乙酯为母体,分别以氯丙烯和氯化苄为桥连基设计合成了两种季铵盐（DMA-1和DMA-2）。利用红外光谱、核磁共振氢谱证实了所得产物与设计相一致。再依次通过失重实验、电化学实验、AFM、接触角等手段测试了Q235钢在含有DMA-1 和DMA-2的1mol/L盐酸中的缓蚀性能,探讨了其在Q235钢表面的吸附和缓蚀机理。结果显示：在较高温度下,DMA-1和DMA-2仍能牢固吸附在Q235钢表面,当所加入缓蚀剂的浓度为100 mg/L 时,缓蚀率均可达92.7%以上,显示出良好的缓蚀性能,且 DMA-1比DMA-2具有更好的缓蚀效果。热力学计算结果表明DMA-1和DMA-2在Q235钢表面的吸附是化学吸附,过程自发、放热,且符合Langmuir等温吸附,属于良好的阳极型缓蚀剂。量子化学计算结果表明了DMA-1更容易提供或接受电子,进一步研究了DMA-1和DMA-2的分子结构与活性位点。     

甲基丙烯酸乙基咔唑酯的合成与表征

以新型光电材料的一种原料羟乙基咔唑和甲基丙烯酸甲酯为原料,对甲苯磺酸为催化剂,对苯二酚为阻聚剂,采用酯交换法合成甲基丙烯酸乙基咔唑酯。采用紫外光谱(UV-vis)傅立叶变换红外光谱(FT-IR)对产物的结构进行了表征。     

RAFT乳液聚合法合成线形三嵌段丙烯酸酯共聚物及其在PVC中的应用

摘要 本文采用可逆加成断裂链转移试剂（RAFT）通过乳液聚合法合成了分子量分布指数为1.8的甲基丙烯酸甲酯-g-丙烯酸丁酯-g-甲基丙烯酸甲酯（MMA-g-BA-g-MMA,MBM）三嵌段共聚物并将其与PVC进行共混。利用转矩流变仪测试了共混物的塑化行为;用动态力学谱仪(DMA)测试了共混物的动态力学行为并测试了共混物的力学性能。结果表明,MBM的加入可以有效减小PVC的塑化时间和平衡扭矩;随着MBM含量的升高,共混物储能模量 随MBM含量的增加出现一定程度的减小,力学内耗tanδ峰值先减小后增大,共混物的Tg升高了约5 ℃。当MBM含量在25 wt％时,共混物具有最大的冲击强度,相较于纯PVC提高了3.0倍。MBM可以作为PVC的一种有效的加工助剂和增韧助剂。     

三硫代碳酸酯的制备及其调控的RAFT聚合

综述了三硫代碳酸酯的合成方法及其在调控RAFT聚合反应中的应用,并对各方法的特点、适用范围和局限性进行比较,并对该类研究提出展望。     

2-乙烯基吡啶-甲基丙烯酸甲酯两嵌段共聚物的合成与表征

采用阴离子活性聚合方法合成了聚2-乙烯基吡啶(P2VP)-聚甲基丙烯酸甲酯(PMMA)两嵌段共聚物(P2VP-b-PMMA),并采用GPC、FT-IR、NMR等手段进行了结构表征.结果表明,聚合产物为数均分子量103166、多分散指数1.08的单分散P2VP-b-PMMA.     

Copolymerization of 2-(4-tert-butylphenoxy)-2-oxo-ethyl Methacrylate with Methyl Methacrylate and Styrene: Synthesis, Characterization, and Monomer Reactivity Ratios

A tertierbutylphenoxy group containing methacrylate based monomer 2-(4-tert-butylphenoxy)-2-oxo-ethyl methacrylate (TBPOEMA) was synthesized by reacting 4-tertierbutylphenyl chloroacetate (TBPClAcO) with sodium methacrylate in acetonitrile. TBPClAcO was prepared by reacting tertierbutylphenol dissolved in benzene with chloroacetylchloride. The free-radical-initiated copolymerization of TBPOEMA, with methyl methacrylate (MMA) and styrene (ST) was carried out in dimethylsulphoxide (DMSO) solution at 65°C using 2,2-azobisisobutyronitrile (AIBN) as an initiator with different monomer-to-monomer ratios in the feed. The monomer TBPOEMA and copolymers were characterized by FTIR, ¹H- and ¹³C-NMR spectral studies. The copolymer composition obtained from the ¹H-NMR spectra led to the determination of reactivity ratios. The reactivity ratios of the monomers were determined by the application of Finemann–Ross and Kelen–Tüdös linear methods and the Behnken nonlinear least-squares method. The analysis of reactivity ratios revealed that MMA and ST are more reactive than TBPOEMA, and copolymers formed are statistical in nature. The molecular weights _w and _n) and polydispersity index of the polymers were determined using gel permation chromagtography. Thermogravimetric analysis of the polymers reveal that the thermal stability of the copolymers increases with an increase in the mole fraction of TBPOEMA in the copolymers. Glass transition temperatures of the copolymers were found to decrease with an increase in the mole fraction of TBPOEMA in the copolymers. The apparent thermal decomposition activation energies (E _d) were calculated by Ozawa method using the SETARAM Labsys TGA thermobalance.     

N-（3-二甲氨基）烷基丙烯酰胺的合成研究

N-（3-二甲氨基）烷基丙烯酰胺是一类常用化合物的统称,比较具有代表性的化合物是N—（3-二甲氨基、丙基丙烯酰胺（简称DMAPAA）,在常温下是流动性液体,为不饱和叔胺。DMAPAA主要用做聚合物的单体、油田注水剂、絮凝剂、造纸助剂、分散剂、涂料助剂、医药中间体等。由于其分子结构中存在着叔胺基团和乙烯基团．能形成季铵盐或发生聚合反应,具有如下特点：单体活性高、形成聚合物的相对分子质量大、呈碱性且显阳离子性、水溶性和醇溶解性都较好、能被广泛应用做石油污水处理和造纸废水处理的第四代絮凝剂单体、还可以用做石油和天然气三次开采的化学助剂单体等。但是,由于它的合成条件非常苛刻,国内还没有成熟的合成工艺条件及设备．主要依靠进口。目前世界上只有德国和日本的工厂具有较完善的合成工艺条件．对单体以及相关产品的研究和开发有较强的理论意义和应用价值。该产品在国内外都具有广阔的市场前景．对国家和企业都具有巨大的经济和社会效益．     

用MADIX/RAFT聚合合成聚(N-乙烯基己内酰胺)

MADIX/RAFT聚合是黄原酸酯调控的可逆加成-断裂链转移自由基聚合,它可用于调控非共轭单体的活性/可控自由基聚合。以乙二醇为原料,将乙二醇的两个羟基转化为O-乙基黄原酸酯,得到黄原酸酯双官能团链转移剂(CTA)。用这个CTA调控N-乙烯基己内酰胺(NVCL)的MADIX/RAFT聚合,合成了聚(N-乙烯基己内酰胺)。用1H NMR谱证明了所得聚合物和中间产物的结构。     

Atom Transfer Radical Block Copolymerization of 2‐(N,N‐Dimethylamino)ethyl Methacrylate and 2‐Hydroxyethyl Methacrylate

Block copolymerization of 2‐(N,N‐dimethylamino)ethyl methacrylate (DMAEMA) with 2‐hydroxyethyl methacrylate (HEMA) via atom transfer radical polymerization (ATRP) was studied in methanol using a macroinitiator method and a “one‐pot” sequential addition method. The polymerization sequence of the two monomers strongly affected the block copolymer formation. When DMAEMA was used as the first monomer, both methods produced block copolymer samples containing significant amounts of DMAEMA homopolymer chains, because of the elimination of active halogen chain‐ends during the preparation of polyDMAEMA. Well‐controlled block copolymers with various block lengths were obtained via the macroinitiator method when polyHEMA was used as macroinitiator to initiate the polymerization of DMAEMA. The sequential addition method, in which HEMA was polymerized first with 90% conversion and DMAEMA was subsequently added, also yielded controlled block copolymers when the polymerization was carried out at room temperature with the DMAEMA conversion below 60%. Increasing the temperature to 60 °C promoted the copolymerization rate but the reaction suffered from gel formation. The addition of water to the system accelerated the polymerization rate, but led to the loss of the system livingness.

Gel permeation chromatograms of poly(HEMA‐b‐DMAEMA). The samples were prepared in methanol at room temperature with different block molecular weights using the macroinitiator method.