聚十二烷二元酸丁二酯及其共聚酯的结晶行为研究

聚十二烷二元酸丁二酯是长碳链脂肪族聚酯中的一种新的聚合物材料．近年来，随着对环境问题的日益重视，利用脂肪族聚酯容易水解的特性，开发生物降解脂肪族聚酯材料的研究得到广泛开展．目前脂肪族二元酸酯的研究大多是围绕聚丁二酸酯、聚乙二酸酯及其共聚酯这一类降解速度较快的材料进行的．虽然这些聚酯已有部分商品化，但远远不能满足对特定降解速率材料的需求．长碳链脂肪族聚酯由于其具有类似PE的结构特征，又兼具聚酯的结构特征，有望在可降解包装材料、书籍装订、服装用热熔胶等方面获得广泛的应用．     

由脂肪族二酰胺二醇合成聚酯酰胺及表征

利用脂肪族二元酸酯与乙醇胺反应容易获得的对称二酰胺二醇,经缩聚合成聚酯酰胺预聚体,并针对端羧基和端羟基同时扩链来提高分子量,获得可生物降解的聚酯酰胺.首先将N,N′-二(2-羟乙基)草酰胺(HEOA)或N,N′-二(2-羟乙基)己二酰胺(HEHA)与己二酸和丁二醇缩聚,制备同时带有端羧基及端羟基的脂肪族聚酯酰胺预聚体,通过1,4-双(2-噁唑啉)苯及己二酰双己内酰胺混合扩链剂扩链,获得高分子量脂肪族聚酯酰胺,并通过红外、1H-NMR、DSC及TGA对其结构和热性能进行了表征.结果表明,预聚体在制备过程发生了一定的酯-酰胺交换反应;扩链后聚合物的熔点、熔融焓和热稳定性有所下降;但热稳定性仍接近或略高于聚己二酸丁二酯.     

含有脂肪族侧链的聚醚醚酮的合成、表征及结构与性能关系

以苯酚和含有不同链长的长链脂肪酮作为原料, 制备了与双酚A结构相似的双酚单体, 并与4, 4'-二氟二苯酮共聚, 合成了几种含有不同长度脂肪族侧链结构的聚醚醚酮类(PEEKs)聚合物. 利用元素分析和核磁共振氢谱(1H NMR)对所合成的双酚单体进行了表征, 并用红外光谱(FTIR)\, 示差量热扫描仪(DSC)、热失重分析仪(TGA)和电子拉力机对所合成的聚合物结构和性能的关系进行了研究.     

脂肪族聚碳酸酯及其在医学中的应用

脂肪族聚碳酸酯具有优良的生物降解性、生物相容性和可功能化性等特点,近十几年来在生物医学领域得到了迅速发展。结合本实验室对生物可降解脂肪族聚碳酸酯的研究工作以及国内外研究现状,根据高分子链的几何形状对脂肪族聚碳酸酯进行了分类介绍,综述了它们的合成方法及其在生物医学领域中的应用,同时展望了脂肪族聚碳酸酯的未来发展趋势。     

尿素催化醇解合成长碳链脂肪族碳酸二酯

氧化锌;尿素催化醇解合成长碳链脂肪族碳酸二酯     

二氧化碳与环氧化合物共聚催化剂研究进展

二氧化碳是一种廉价、低毒、资源丰富的可用于有机合成的理想原料。由二氧化碳和环氧化合物共聚合成的脂肪族聚碳酸酯具有生物可降解性。自1969年井上祥平等发现二氧化碳和环氧化合物通过共聚反应合成脂肪族聚碳酸酯以来,利用二氧化碳制备高分子材料一直备受人们注目。该过程的关键是寻找具有高选择性的高效催化剂,三十余年来通过各国科学家的不懈努力已取得了不少成果,本文对其研究的最新进展进行了综述。     

端羧基酯交换法合成高分子量大豆油基聚酯

以大豆油为原料可高效合成大豆油基二元醇(SOD),通过与二元酸的熔融缩聚获得大豆油基聚酯.然而传统的酯化和酯交换机理无法获得高分子量的聚酯产物,其原因在于反应过程中醇酸单元摩尔比偏离达到高分子量所需的等摩尔比条件.本研究采用一种新型的端羧基酯交换(CET)机理成功合成了高分子量的大豆油基聚酯,首先以过量的可升华二元酸与SOD酯化生成羧基封端预聚物,再通过CET在高真空下脱除过量的二元酸,动态地逼近醇酸等摩尔比条件,从而获得了黏均分子量可达123 kDa的高分子量大豆油基聚酯.该聚酯具有良好的热稳定性和高透明性,其黏附性能可达压敏胶黏剂的商用标准.这种含不饱和脂肪族侧链的聚酯还可通过巯-烯"点击"反应引入季铵盐基团,获得抗菌型大豆油基聚酯.     

三亚甲基碳酸酯基响应性脂肪族聚碳酸酯的研究进展

脂肪族聚碳酸酯是一类可生物降解、生物相容性的材料,在生物医药方面引起广泛关注。两亲性脂肪族聚碳酸酯聚合物中,聚碳酸酯部分凭借其疏水性能处于胶束内核部位,且该部分通过物理包覆、化学键合等方式使聚合物与药物相结合,提升了响应环境下药物运输与释放的方式与能力。因此,本工作对近年来响应性脂肪族聚碳酸酯的研究进展进行了综述,主要阐述了具有外环境刺激响应(pH、光、温度和氧化还原)脂肪族聚碳酸酯的合成、响应原理、在药物传递和释放方面的应用。     

开环可控聚合制备脂肪族聚酯的最新研究进展

近年来,作为生物降解高分子材料,脂肪族聚酯由于良好的生物降解性及生物相容性受到人们的广泛关注。脂肪族聚酯在环境友好材料和生物医用材料领域都具有极大的应用价值,目前,部分聚酯材料已经商品化。与此同时,脂肪族聚酯的合成方法尤其是活性开环聚合也成为学术界及工业领域的研究热点。采用开环聚合法得到的聚合产物化学组成精确、分子量分...     

含糖嵌段聚合物的合成

含糖嵌段聚合物生物降解性和生物相容性好,其分子链上含有大量可反应性基团(如羟基、氨基或羧基),可进行后续功能化改性,在热塑性弹性体、增容剂、表面活性剂、生物降解材料、药物载体材料等方面显示出广阔的应用前景,是近年来发展起来的一种新型功能材料.本文综述了含糖嵌段聚合物的合成研究进展,糖种类涉及寡糖、纤维素、葡聚糖、直链淀粉和透明质酸等,聚合方法主要包括阴离子聚合、阳离子聚合、自由基聚合、开环聚合、酶促聚合、化学偶联等.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.