中国南海海绵Seletta tenuis lindgren中24-亚甲基-27-甲基胆甾醇的结构鉴定

本研究中国南海海绵生物活性成分的过程中,从南海海绵中分离出24-亚甲基-27-甲基胆甾醇,通过IR,^1HNMR,^13CNMR,^1H-^13CCOSY,MS和MS-MS等波谱分析,确证了其化学结构,并详细报道了波谱数据.     

一种用于质子交换膜材料的磺化聚醚醚砜的合成

以发烟硫酸和4,4′-二氯二苯砜为原料,通过磺化反应,制得磺化二氯二苯砜,然后利用亲核缩聚反应,调整磺化单体和非磺化单体的比例,与四甲基联苯二酚进行聚合,制取了系列具有不同磺化度的聚醚醚砜,并对聚合物的结构进行了研究.     

H大孔吸附树脂的磺化反应

本文以H大孔吸附树脂为母体,进行磺化反应,制得新型大孔强酸离子交换树脂,通过对这类树脂的交换量和物理结构的测定,研究了在H树脂上进行磺化反应的影响因素,同时也得到了这类强酸离子交换树脂的一些物化性能参数,为其应用提供了一定的参考数据。     

改性强酸性阳离子交换树脂的结构和性能

本文对以多元共聚合成的改性强酸性树脂A—4的结构和性能作了较为详细的研究,并与国内外同类树脂进行了比较。实验结果表明,极性单体的加入有利共聚合反应和官能团反应的进行,使所得树脂的网状结构均匀性得到改善。A—4树脂是一种具有耐渗透冲击、耐压和抗氧化性能好的改性强酸性阳离子交换树脂。采用加入极性单体进行多元共聚是增强离子交换树脂的一种简单而有效的方法,自六十年代起就有不少专利报道,但至今未见商品生产。本文通过对以多无共聚得到的改性强酸性树脂A—4与国内外同类树脂的热分析(DSC),珠体溶胀性能,磺化速率的研究;抗氧化性能,耐压性和耐渗透冲击性能的测定;以及对卡那霉素的吸附试验,探讨了此类树脂的结构和性能关系。     

多司马酯的波谱特征与结构确证

对多司马酯的紫外(UV)光谱、红外(IR)光谱、氢谱(^1HNMR)、碳谱(^13CNMR)、氢氢相关谱(^1H-^1HCOSY)、碳氢相关谱(HETCOR)及碳氢远程相关谱(COLOC)进行了解析报道,并对所有的^1HNMR,^13CNMR谱的信号进行了归属,讨论了红外吸收光谱峰所对应的官能团的振动形式。     

选择性远程DEPT技术用于吡咯里西啶类生物碱的结构测定和核磁共振研究

本文从峨眉千里光中分得二个吡咯里西啶类生物碱.经测定,一个为阔叶千里光碱,另一个为新阔叶千里光碱.采用选择性远程^13CDEPT技术对这二个化合物的结构及其^1H和^13CNMR谱峰归属作了研究.     

用~(13)CNMR研究丁苯阴离子共聚体系中各活性种的竞聚率

本文利用~(13)CNMR测试数据,计算了丁苯阴离子共聚体系中各活性种的竞聚率,得到了与动力学数据较一致的结果,对阴离子聚合反应Markov级数问题进行了讨论,并对用积分法计算高转化率下共聚物二元组组成进行了探索。     

翠雀花明的化学结构

分自大花翠雀(delphinium grandiflorum)地上部分的一个新二萜生物碱,命令为翠雀花明(delgramine,1),根据IR,MS,^1H和^13CNMR,OFR及^1H-^1HNOESY,^13C-^1HCOSY二维谱阐明了其化学结构.     

一种新型的用于质子交换膜燃料电池的磺化聚醚醚酮酮

以发烟硫酸和4,4-二(4-氟苯甲酰基)苯[1,4-bi(4-fluorobenzoyl)benzene]为原料,通过磺化反应,制得磺化二氟三苯二酮[1,4-bi(3-sodiumsulfonate-4-fluorobenzoyl)benzene].利用亲核缩聚反应,调整磺化单体和非磺化单体的比例,与酚酞进行聚合,制取了具有不同磺化度的聚醚醚酮酮,并对聚合物的结构进行了表征.结果表明,此系列磺化聚醚醚酮酮的膜制品具有良好的离子交换特性,可望应用于燃料电池膜.     

羧基含量可控氮杂环聚芳醚砜反应性增韧601环氧树脂

采用酚酞啉(PPL)、二氮杂萘酮双酚(DHPZ)等单体制备了羧基含量可控的杂萘联苯结构聚芳醚砜(PPES-P),聚合物主链羧基含量与分子设计一致性较高,玻璃化转变温度(Tg)均达到260°C以上,具有优异的热稳定性和溶解性.进一步选取不同羧基含量的PPES-P对601环氧树脂体系进行反应性增韧改性,考察PPES-P羧基含量对树脂体系力学性能和热稳定性的影响.结果表明:PPES-P树脂与601环氧树脂相容性较好,羧基作为交联点能够参与环氧树脂固化反应,强化了增韧组分与基体树脂的界面结合能力,PPES-P反应性增韧改性不仅提高了601环氧树脂体系的冲击与弯曲性能,还保持了树脂体系较高的Tg,其中PPL与DHPZ结构单元为1:3的PPES-P13改性后树脂冲击强度提高了43%,试样断裂面为均相结构且呈韧性断裂形貌.     

On the structure and cure acceleration of phenol-urea-formaldehyde resins with different catalysts

Phenol-urea-formaldehyde (PUF) resins with different catalysts [calcium oxide (CaO), sodium carbonate (Na₂CO₃), zinc oxide (ZnO), and magnesium oxide (MgO)] were prepared to accelerate the cure of the resin at low temperature. The cure-acceleration effects of catalysts on chemical structure and cure characteristics of PUF resins were investigated by using both liquid ¹³C nuclear magnetic resonance (NMR) and differential scanning calorimetry (DSC). The liquid ¹³C NMR analysis indicated that the catalyst such as CaO seemed to present a retarded effect on the polycondensation reaction of phenolic components with urea units, while the Na₂CO₃ appeared to promote the self-condensation reaction of phenolic methylol groups at para position toward the formation of para-para methylene linkage. Both ZnO and MgO in PUF resins promoted self-condensation reaction of para methylol groups and condensation reaction of ortho methylol groups with para methylol groups. The catalysts such as Na₂CO₃, ZnO, and MgO can make PUF resins cure at a low temperature. Among these catalysts, the MgO had the most significant accelerating effect on polycondensation and cure reaction of PUF resin.     

酞侧基聚芳醚酮的核磁共振研究(Ⅰ)──链结构及NMR谱的归属

用1D NMR方法研究酞侧基聚芳醚酮(PEK-C)链结构,用二维同核化学位移相关与二维异核化学位移相关实验方法对1D NMR谱峰进行归属,探讨了二维异核远程相关实验在缩聚高分子研究中的应用,为PEK-C修饰机理以及共混相容机理的研究提供重要信息。溶液NMR谱图数据表明,PEK-C具有较规整的链结构。     

Surface Modification of Colloidal Silica by Sulfonation Route for Super-Hydrophilicity

Colloidal silica was chemically modified by a two-step method including an olefin sulfonation route as a preliminary study for super-hydrophilic applications. The hydrophobic vinyl groups were initially bonded chemically to the hydroxylated silica surface using the trichlorosilane coupling agents. The vinyl-terminated silica was then sulfonated by addition reaction with chlorosulfonic acid. The modified silica was investigated using DRIFT, TGA, element analysis, solid-state ²⁹Si- and ¹³C CP-MAS NMR. The vinyl-terminated specimen showed a characteristic IR absorption band at 1600 cm^–1 and a weight loss of approximately 3% starting at 350°C while the ²⁹Si NMR peaks at 70.9 and 79.8 ppm and ¹³C NMR at 136 ppm and 129.8 ppm were assigned to a vinyl group bonded to silica. Elemental analysis of the sulfonated silica indicated the presence of sulfur, carbon and hydrogen. Thermal decomposition in range 150–600°C was due to the presence of sulfonated organics and unreacted vinyl groups while the new signals on ¹³C NMR, which were in the range 70–15 ppm, were assigned to sulfonated carbons.     

TG-DTA study of melamine-urea-formaldehyde resins

The thermal behaviour of MUF resins from different suppliers with different content of melamine was studied, along with the ¹³C NMR spectroscopic analysis of resin structure and the testing of particleboards in current production at Estonian PB factory Pärnu Plaaditehas AS. The chemical structure of resins from DMSO-d₆ solutions was analysed by ¹³C NMR spectroscopy on a Bruker AMX500 NMR spectrometer. The melamine level in different MUF resins is compared by the ratios of carbonyl carbon of urea and triazine carbon of melamine in ¹³C NMR spectra. Curing behaviour of MUF resins was studied by stimultaneous TG-DTA techniques on the Labsys? instrument Setaram. The shape of DTA curves characterisises the resin synthesis procedure by the extent of polymerisation of UF and MF components and is in accordance with structural data.     

一种金属洗涤剂的NMR分析

由于精细化工行业的迅速发展,作为“工业味精”的表面活性剂,已广泛进入日化、轻工、纺织、建筑、石化、金属加工等生产领域,对其的分析也显得日益重要。表面活性剂的分析历来是比较困难的课题之一,而通过核磁共振(NMR)进行定性和定量的文献则更少[1]。本文利用NMR为多种表面活     

Thermal behaviour of hydroxymethyl compounds as models for adhesive resins

Urea–formaldehyde (UF) and phenol–formaldehyde (PF) resins are the most widely used wood adhesives. The first stage in resin manufacturing is the formation of methylol derivatives which polycondensation leads to building the tridimensional network. Understanding the behaviour of methylol compounds in curing provides useful information for developing appropriate resin structures. Thermal behaviour of N,N′-dihydroxymethylurea, 2- and 4-hydroxymethylphenols, urea and phenol as model compounds for UF, PF and phenol–urea–formaldehyde (PUF) resins was followed by TG-DTA method. The measurements were carried out by the labsys instrument Setaram at 30–450 °C in nitrogen flow. The characteristic signals for model compounds and for some reaction mixtures were measured by high resolution ¹³C NMR spectroscopy.     

Changes in curing behaviour of aminoresins during storage

Summary The curing behaviour of commercial UF and MUF resins, stored at room temperature nearly up to gelation, is studied by simultaneous TG-DTA technique and structural changes of resins are also followed during aging. On the basis of ¹³C NMR spectra, the main chemical reaction during UF resin storage is the formation of methylenes and dimethylene ethers linked to secondary amino groups. Aging of resins results in a decrease of cure rate which is related to lower concentration of active functional groups and decrease in molecular mobility. On DTA curve, the resin with higher content of methylol groups reveals the curing exotherm earlier. With decreasing methylol content during storage, the peak maximum of exotherm is shifted to higher temperature value. Advanced polycondensation and sedimentation processes during storage produce partly locked in macromolecule structure water, and the water evaporation endotherm on DTA curve shifts to considerably higher temperature. The aged MUF resins are chemically less changed than UF resins and the aging process mainly involves noncovalent network formation due to complex molecular structure.     

三苯基咪唑共轭Schiff碱的合成及其光学性能

联苯甲酰、对硝基苯甲醛和乙酸铵在冰乙酸介质中经缩合反应制得2-(4-硝基苯基)-4,5-二苯基咪唑(1); 1经铁粉还原制得2-(4-氨基苯基)-4,5-二苯基咪唑(2); 2与4-二甲氨基苯甲醛经缩合反应合成了一种具有D-π-A结构的新型三苯基咪唑Schiff碱（3）,其结构经¹H NMR,¹³C NMR, IR和MS(ESI)表征。利用紫外-可见吸收光谱和荧光光谱研究了3在不同溶剂中的光物理行为。结果表明：3的最大吸收峰位于311~332 nm和378~380 nm,荧光发射峰位于433~436 nm和457~461 nm。由于具有D-π-A结构,3表现出明显的扭曲分子内电荷转移现象。     

羧甲基木薯淀粉的取代方式研究

采用高效液相色谱(HPLC)和核磁共振波谱(^1HNMR)分析了混水/有机介质中合成羧甲基木薯淀粉的取代方式。发现HPLC是一种测定不同条件下合成的羧甲基木薯淀粉取代度(DS)的可靠方法。在测量的范围内,未取代、一取代、二取代和三取代无水葡萄糖单元的摩尔分数分布和Spurlin模型非常吻合。用高分辨率500MHz^1HNMR分析了木薯淀粉羧甲基过程的取代度和反应顺序。依据淀粉和羧甲基淀粉(CMS)的结构确定了各个峰位置。比较所得数据发现：依据HPLC计算的DSHPLC小于从500MHz^1HNMR计算所得的DSNMR。无水葡萄糖单元中C2、C3和C6的羧甲基化反应顺序为C6＞C2＞C3。     

Heterotelechelic poly(oxazolidine-acetals) and their functionalization

Telechelic poly(1,3-oxazolidine-acetal)s with -CH₂OH and -CHO groups were synthesized by polycondensation of the 2-amino-2-hydroxy-1,3-propanediol ( 1 ) (TRIS) with terephthaldehyde ( 2 ). The degree of polymerization (DP) was controlled by the ratio of 1 to 2 at the given reaction time. Characterization was achieved by ¹H and ¹³C NMR and IR spectroscopy. The distribution of oxazolidine-acetal units in the polymer chain has been performed using ESI-MS. The activities of telechelic poly(oxazolidine-acetal) were determined in reaction oxidation (4-chloroperbenzoic acid), reduction (CH₃MgCl) and nucleophilic substitution (acylation, alkylation).