聚醚型化合物的核磁共振碳谱解析

论述了以环氧乙烷、环氧丙烷为代表的聚醚型化合物的核磁共振碳谱特点及其立构规整性特征，并通过对主链碳谱和末端基碳谱的解析，讨论了聚合反应机理和聚合物组成。     

固体变温核磁共振碳谱研究主链型热致液晶聚醚聚氨酯弹性体

固体变温核磁共振碳谱研究主链型热致液晶聚醚聚氨酯弹性体陈群，杨光，王源身（华东师范大学分析测试中心上海２０００６２）余学海（南京大学高分子系南京２１０００８）黑子弘道，安藤勋（日本东京工业大学高分子工学科）关键词主链型热致液晶聚氨酯弹性体，固体变温高...     

~(13)C-NMR化学位移与聚合物的构象——Ⅱ.1,2-聚丁二烯仲碳(—CH_2—)的~(13)C-NMR谱研究

在1,2-聚丁二烯链分子中,导致仲碳(—CH_2—)谱峰分裂的原因是存在着两种gauche排列。在这样一个复杂体系中,由于主链仲碳与叔碳的gauche排列占有重要的位置,因此主链叔碳对化学位移的贡献对于仲碳谱有着决定性的影响。相比之下,乙烯基的贡献要小得多。两种贡献分别是γ_1=—6.37——6.41ppm与γ_2=0.0——1.56ppm。在不计入侧基的影响或同时考虑乙烯基的贡献这两种情况下,均方误差MSE分别是0.166×10~(-2)和0.364×10~(-2)ppm~2。本文同时讨论了模型链的种类、链长以及温度对键概率的影响。并指出有个别反常的情况发生。文中还对间同1,2-聚丁二烯的链结构进行了分析。     

六氟磷酸二（2,2—联吡啶）（2,2‘—联吡啶—4,4’—二羧酸）合钌（Ⅱ）的二？…

利用核磁共振氢谱和碳谱研究了电化学探讨六氟磷酸二（２,２’－联吡啶）（２,２‘－联吡啶－４,４＝－二羧酸）合钌（Ⅱ）的立体结构,并通过二维’Ｈ－Ｈ同核相关及Ｈ－＾１３Ｃ异相关技术对其氢谱和碳谱进行了归属。     

4—叠氮—4—脱氧—4‘—去甲基表鬼臼毒素的^1H和^13C核磁共振分析

用＾１Ｈ－＾１ＨＣＯＳＹ，ＨＭＱＣ和ＲＯＥＳＹ二维核磁共振等技术对标题化合物的氢谱和碳谱进行了完全归属。     

开链冠醚型手性双(噻)唑啉配体的合成及其应用研究

合成了6个新的具有开链冠醚结构的手性双噁唑啉配体(4a～4d)和手性双噻唑啉配体(5b,5c),用红外光谱、核磁共振氢谱、核磁共振碳谱、元素分析等对其结构进行了表征.初步考察了其在Henry反应中的不对称催化活性.     

开链冠醚型手性双噁（噻）唑啉配体的合成及其应用研究

合成了6个新的具有开链冠醚结构的手性双噁唑啉配体（4a～4d）和手性双噻唑啉配体(5b，5c)，用红外光谱、核磁共振氢谱、核磁共振碳谱、元素分析等对其结构进行了表征。初步考察了其在Henry反应中的不对称催化活性。     

碳碳相关谱测定泽泻萜醇F的结构

从泽泻中分离出新化合物泽泻萜醇F，采用二维核磁共振碳相关技术研究了该化合物的骨架结构。结合碳碳相关谱及远程碳氢相关谱等其它二维核磁共振技术，分析了该化合物的常规氢谱和碳谱，并准确归属了质子和碳核的化学位移。     

几种医用卟啉的核磁共振谱

通常对于带侧链羧基的卟啉,是以其酯的形式在CDCl₃溶液中测量核磁共振谱的。与之相反,本文直接提供血卟啉、原卟啉和卟啉C在酸性溶液中的质子谱和碳-13谱。这种途径有利于这些医用卟啉的结构鉴定和生产监控。     

2-O-乙酰和3-O-乙酰-4,6-苯亚甲基-α-D葡萄糖甲甙的核磁共振鉴别法

本文报告了用同核相关二维核磁共振氢谱和核磁共振碳谱两种核磁共振方法来鉴别氟代去氧六碳糖化合物合成中关键性中间体2-O-乙酰和3-O-乙酰-α-D-4,6-苯亚甲基葡萄糖甲甙的结果。     

RANDOM COPOLYMER OF PROPYLENE OXIDE AND ETHYLENE OXIDE PREPARED BY DOUBLE METAL CYANIDE COMPLEX CATALYST

Copolymerization of propylene oxide (PO) and ethylene oxide (EO) using double metal cyanide (DMC) complexas the catalyst was carried out. The structure of random copolymers was confirmed by ~(13)C-NMR and IR spectra. ~1H-NMRanalysis shows that the EO content in the copolymer is the same as that in the initial monomer feed. Moderate molecularweight copolymers with various EO content were obtained and their values of molecular weigh distribution (MWD) fell inthe range of 1.21-1.55. It was found that the molecular weight of copolymers is controlled by the mass ratio of EO + PO toinitiator moles used. The reaction rate as well as polymer yield decrease with increasing EO content in the feed composition.     

乙酰丙酮钇催化环氧氯丙烷的均聚合与共聚合

用过渡金属络合催化剂聚合环氧氯丙烷能获高分子量的聚合物。稀土络合催化剂对环氧乙烷,环氧丙烷及环硫丙烷的开环聚合具有明显效果。本文选用Y(acac)_3-H_2O-Al(i-Bu)_3催化剂,考察环氧氯丙烷的均聚合及其与环氧乙烷,环氧丙烷的共聚合,并用核     

A Fourier transform infrared study of the phase transition in aqueous solutions of Ethylene oxide–propylene oxide triblock copolymer

The phase transition between unimer and micellar phases of poly(ethylene oxide)–poly(propylene oxide)–poly(ethylene oxide) (PEO–PPO–PEO) triblock copolymer Pluronic P105 in aqueous solution has been investigated as a function of temperature using Fourier transform infrared spectroscopy. The transition of 8 wt% Pluronic P105 in aqueous solution was found to occur at 25 °C. As temperature increases, PO blocks appear to be stretched conformers with strong interchain interaction, and the formation of a hydrophobic core in the micellar phase. The EO chains are found to change to a more disordered structure with low-chain packing density from the unimer phase to the micellar phase. Both the EO and PO blocks exhibit dehydration during the phase transition. Received: 17 September 1998 Accepted in revised form: 10 December 1998     

Aqueous nonionic copolymer-functionalized laponite clay. A thermodynamic and spectrophotometric study to characterize its behavior toward an organic material

The affinity of functionalized Laponite clay toward an organic material in the aqueous phase was explored. Functionalization was performed by using triblock copolymers based on ethylene oxide (EO) and propylene oxide (PO) units that are EO(11)PO(16)EO(11) (L35) and PO(8)EO(23)PO(8) (10R5). Phenol (PhOH) was chosen as organic compound, which represents a contaminant prototype. To this purpose, densities and enthalpies of mixing as well as PhOH UV-absorption spectra were determined. The enthalpy and the spectrophotometry revealed PhOH-Laponite interactions whereas the volume did not. It emerged that the area occupied by PhOH on the Laponite surface is equal to that computed from the partial molar volume of PhOH in water, corroborating the insensitivity of the experimental volumes to the adsorption process. The situation where both PhOH and copolymer are simultaneously present in the aqueous Laponite suspension was also investigated. It turned out that the copolymer replaces PhOH from the water/Laponite clay interface, resulting in L35 being the more efficient. Moreover, the lateral copolymer-phenol interactions enhance the anchoring of PhOH to the solid surface. The reverse copolymer exercises the most important relevant effect. The UV-absorption spectra of PhOH in the water + copolymer + Laponite mixtures provided information that is consistent with those given by the calorimetric experiments. In conclusion, the aqueous copolymer-functionalized Laponite presents surface properties very different from the bare Laponite, favoring the removal of the organic compound from the solid surface.     

Microenvironmental and conformational structure of triblock copolymers in aqueous solution by 1H and 13C NMR spectroscopy

1H and 13C nuclear magnetic resonance (NMR) spectra of poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymers in D2O solutions have been systematically investigated. The detailed assignments of various 1H and 13C NMR signals are presented. The hyperfine structure of PO -CH2- protons was clearly assigned, the arising reason of this hyperfine structure was attributed to the influence of the chiral center of -CHCH3- groups and the direct coupling between the PO -CH2- and -CH3 protons. The external standard 2,2-dimethyl-2-silapentane-5-sulfonate sodium salt (DSS) was firstly applied in this system. Accurate chemical shift values referenced to the external standard DSS were obtained. 1H NMR chemical shift of PO -CH2- and -CH3 signals shows a larger decrease in ppm values than that of EO -CH2- signal with the increase of PPO/PEO ratio or temperature indicating that PO segments exist in a more hydrophobic microenvironment. A new resonance signal assigned to the PO -CH2- protons appeared when the temperature is above the CMT, which is attributed to the breakdown of the intra-molecular (C-H)...O hydrogen bond between the PO -CH2- protons and the ester oxygens. The breakdown of this intra-molecular hydrogen bond may result in a decrease of gauche conformers of the PPO chain. The increase of 13C NMR chemical shift of block copolymers validates this conformational change assumption. It can be inferred that the amount of gauche conformers decreases whereas that of trans conformers increases in both PO and EO chains when elevating the PPO/PEO ratio or temperature. The observed 13C NMR chemical shifts of PO segments show a bigger increase than those of EO segments, supporting the formation of a nonpolar microenvironment around PO segments.     

氧化石墨烯水热还原前后的发光光谱

分别采用改进Hummers方法和水热还原法制备了氧化石墨烯(GO)和还原氧化石墨烯(RGO)。 GO和RGO经透射电子显微镜(TEM)、紫外-可见吸收光谱(UV-Vis)、红外光谱(IR)、荧光发射和激发光谱(PL、PLE)等技术手段进行了表征。 荧光发射光谱显示,氧化石墨烯(GO)在可见光的激发下可以得到波长在600~800 nm范围内的宽谱近红外荧光。 通过比较氧化石墨烯水热还原前后的光谱变化,发现氧化石墨烯近红外荧光起源于氧化石墨烯的表面含氧基团,如C=O、COOH。 近红外荧光穿透性好、对生物组织损坏小,非常适合于生物成像,预示着氧化石墨烯在生物成像方面的应用潜力。     

Effect of SDS on the self-assembly behavior of the PEO-PPO-PEO triblock copolymer (EO)20(PO)70(EO)20

The mixed micellar system comprising the poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)-based triblock copolymer (EO)(20)(PO)(70)(EO)(20) (P123) and the anionic surfactant sodium dodecyl sulfate (SDS) has been investigated in aqueous media by small-angle neutron scattering (SANS) and viscosity measurements. The aggregation number of the copolymer in the micelles decreases upon addition of SDS, but a simultaneous enhancement in the degree of micellar hydration leads to a significant increase in the micellar volume fraction at a fixed copolymer concentration. This enhancement in the micellar hydration leads to a marked increase in the stability of the micellar gel phase until it is destroyed at very high SDS concentration. Mixed micellar systems with low and intermediate SDS concentrations form the micellar gel phase in much wider temperature and copolymer concentration ranges than the pure copolymer micellar solution. A comparison of the observed results with those for the copolymers (EO)(26)(PO)(40)(EO)(26) (P85) and (EO)(99)(PO)(70)(EO)(99) (F127) suggests that the composition of the copolymers plays a significant role in determining the influence of SDS on the gelation characteristics of the aqueous copolymer solutions. Copolymers with high PO/EO ratios show an enhancement in the stability of the gel phase, whereas copolymers with low PO/EO ratios show a deterioration of the same in the presence of SDS.     

Interactions between poloxamers in aqueous solutions: micellization and gelation studied by differential scanning calorimetry, small angle X-ray scattering, and rheology

Poloxamers F88 (EO97PO39EO97) and P85 (EO27PO39EO27) are triblock copolymers of ethylene oxide (EO) and propylene oxide (PO), which have the same hydrophobic PO block. We studied aqueous solutions of these two copolymers by the conjoint use of differential scanning calorimetry (DSC), rheology, and small-angle X-ray scattering (SAXS). The results showed that the temperature-induced micellization of aqueous solutions of F88 and P85 was a progressive process followed by gelation for sufficiently concentrated samples. Gelation was due to the ordered packing of micelles under a hexagonal compact (HC) structure for P85 and a body-centered cubic (BCC) phase for F88. Importantly, the phase diagram of F88/P85 mixtures in water was elucidated and showed the destabilization of the HC phase upon addition of small amounts of F88.     

Solvent and temperature gradients in separation of synthetic oxyethylene-oxypropylene block (co)polymers using high-temperature liquid chromatography

Chromatographic behavior of synthetic block (co)oligomer samples (EO)n(PO)m(EO)n and (PO)n(EO)m(PO)n with different distribution of propylene oxide (PO) and ethylene oxide (EO) monomer units was investigated on three types of stationary phases on zirconium dioxide support: Zr-PS (polystyrene), Zr-carbon, and Zr-carbon C18. The effects of the distribution and sequence of the oxyethylene and oxypropylene monomer units on the chromatographic retention depend on the type of the stationary phase, but are strongly affected by the organic modifier (methanol or ACN) in aqueous-organic mobile phase. Special attention was focused on the influence of the mobile-phase composition on the separation according to the EO and PO distribution. Zirconia-based columns are stable at elevated temperatures and can be used in high-temperature LC (HTLC); hence, we investigated the temperature effects on the chromatographic behavior up to 90 degrees C. The applications of solvent and temperature gradients were compared on the zirconia stationary phases in the RP mode.     

氧化环己烯连续进料下二氧化碳-环氧丙烷-氧化环己烯三元共聚物的合成

由于氧化环己烯（CHO）与二氧化碳的共聚反应速度比其与环氧丙烷（PO）快,这种竞聚率的差异导致一锅法所得的二氧化碳-环氧丙烷-氧化环己烯三元共聚物的组成难以稳定控制。 为此本文在稀土三元催化剂下,采用氧化环己烯单体连续进料的方法合成了二氧化碳-环氧丙烷-氧化环己烯三元共聚物,催化效率可达575 g/(mol Zn h)。 三元共聚物的玻璃化转变温度随CHO含量升高而增大,当CHO的摩尔投料比从0.19增加到0.59时,玻璃化温度从44.3 ℃提高到70.1 ℃。 CHO连续进料合成的三元共聚物的组成与投料比基本相近,且连续进料法所合成的三元共聚物只有一个玻璃化转变温度,而普通的一锅法所得的三元共聚物通常存在两个玻璃化转变温度,因此连续进料法是制备组成稳定的二氧化碳-环氧丙烷-氧化环己烯三元共聚物的有效方法。