聚酰胺—46的合成和结构研究（Ⅱ）

用红外光谱、核磁共振和工扫描量热分析等手段对聚酰胺－４６进行了基本表征，并用广角Ｘ射线衍射和扫描隧道显微镜技术对其聚集态结构进行了分析。     

测试条件对聚酰胺粘数测试结果的影响

分析了测试条件对聚酰胺粘数测试结果产生影响的原因。结果表明,样品实验前的烘干处理对聚酰胺粘数结果影响不大,但是对于长期敞口放置的聚酰胺样品以及做异常调查测试等,建议还是有必要对样品进行烘干处理的;浓硫酸的浓度对结果有明显影响,98%浓硫酸的粘数结果比96%浓硫酸的粘数结果至少偏高10 mL/g,对原料的影响更加显著;样品浓度对粘数的结果有显著的影响,样品浓度太低或太高都会导致粘数结果发生明显地偏差。     

对苯二胺和均苯三酸及对氨基苯甲酸制备可溶性芳香聚酰胺共聚物的研究

分别通过一步加料和分步加料的方法,以对苯二胺(A2)、均苯三酸(B3)和对氨基苯甲酸(AB)为原料进行溶液缩聚反应,制备了具有良好溶解性的芳香聚酰胺共聚物.产物的结构通过IR、1H-NMR得到证实.采用IR和1H-NMR对一步加料共聚反应的共聚行为进行研究,并初步考察了3种不同单体对反应的影响.     

聚酰胺―胺的合成表征及对铝酸钠溶液物化性质的影响

用发散法合成以乙二胺为核的聚酰胺―胺(PAMAM 0.5～6.0代),采用元素分析、电位滴定等方法对合成产物进行表征分析,考察了不同分子代数、不同浓度的PAMAM对铝酸钠溶液表面张力和电导率等物理化学性质的影响。结果表明,该条件下合成的PAMAM具有较好的结构完整性。此外随着添加剂PAMAM的增加,铝酸钠溶液的表面张力急剧降低,半代数的PAMAM具有较好的表面活性,有望成为新一代的表面活性剂;整代数的PAMAM也有一定的表面活性。PAMAM属于非离子型表面活性剂,因此随着PAMAM的加入,铝酸钠溶液的电导率改变不大。     

邻苯二胺及其金属配位型含氟聚酰胺磺酰胺的合成与荧光性能

采用溶解聚合法使β-四氟乙烷磺内酯分别与邻苯二胺、二氯-邻苯二胺合锌(Ⅱ)和二氯-邻苯二胺合镉(Ⅱ)开环缩聚,制备出邻苯二胺型和金属配位邻苯二胺型含氟聚酰胺磺酰胺聚合物。通过红外光谱、核磁共振氢谱、电感耦合等离子体发射光谱仪、凝胶渗透色谱等手段,确定其分子链为同时含有酰胺、磺酰胺、氟碳基团、芳环和金属离子的特殊结构;采用紫外-可见分光光度计和荧光分光光度计分析表明:邻苯二胺型含氟聚酰胺磺酰胺具有高荧光量子产率0.65,Cd2+配位后荧光量子产率保持0.65,而络合Zn2+的邻苯二胺型含氟聚酰胺磺酰胺的荧光量子产率降低为0.39,Zn2+对该类聚合物的荧光性能具有选择性。     

超支化聚酰胺的合成与表征

N-(二氨基苯甲酰)氨基乙酸;自缩聚;封端反应;超支化聚酰胺的合成与表征     

Rink Amide树脂结构对多肽合成的影响研究

研究了Rink Amide树脂取代度、溶胀度及肽链的长度不同对肽合成收率的影响,并对影响Rink Amide树脂溶胀度的因素进行了研究,结果表明,合成长肽时低取代度、高溶胀度的Rink Amide树脂能获得较好的肽收率。     

Fe-Mn超细粒子催化剂对FT合成反应的研究Ⅰ.反应条件的影响

在内循环无梯度反应器（Ｂｅｒｔｙ反应器）中研究了Ｆｅ－Ｍｎ超细粒子催化剂费托合成反应的规律。详细考察了温度、压力、空速对ＦＴ反应性能的影响。结果表明,反应条件对催化剂低碳烃及ＣＯ２的选择性等都有一定的影响,在考察的时间范围（１２００ｈ）内,即使在较宽的操作条件下,催化剂仍具有良好的活性和稳定性。还发现随着低碳烯烃选择性的提高,低碳烃的烯烷比下降不明显。     

基于D1蛋白结构的光合作用抑制剂化合物库的组合合成

在所搭建的光合系统Ⅱ (PSⅡ )D1蛋白与先导化合物———氢化脲嘧啶相互作用的复合模型基础上 ,采用固相有机合成的方法平行合成了 8个氢化脲嘧啶类似物 5 ,并用FTIR跟踪了该固相反应 .丙烯酸 (酰氯 )与Wang树脂 1作用得到固载的丙烯酸酯 2 ;2与伯胺经Micheal加成反应生成仲胺 3;随后与异氰酸酯加成得到脲 4;4在酸催化下从树脂上解离的同时关环 ,从而得到氢化脲嘧啶 5 .产物 5的结构经1HNMR ,HPLC和MS所证实 .在此基础上通过变化取代基 ,组合合成了含 9种氢化脲嘧啶的小化合物库 ,它们的结构经GC MS所证实     

Synthesis of High Molecular Weight Polyesters via In Vacuo Dehydrogenation Polymerization of Diols

The Milstein catalyst has proven to be highly effective for the conversion of alcohols to esters, as well as alcohols and amines to amides and polyamides. We have recently found that the catalyst's range can be extended to very efficient in vacuo dehydrogenation polymerization of α,ω‐diols to generate polyesters. The gaseous hydrogen byproduct that is produced is easily removed to drive the equilibrium toward product, which leads to the formation of high molecular weight polymer ( up to 145 000 g mol⁻¹). This optimized methodology works well to polymerize diols with a spacer of six carbons or more. Diols with fewer carbons are cyclized to lactone; the dividing point is the dehydrogenation of 1,5‐pentanediol, which leads to a mixture of polyester and lactone. Reported herein is the synthesis and characterization of five aliphatic polyesters prepared via this novel dehydrogenation polymerization approach.     

Two-Dimensional LDH Film Templating for Controlled Preparation and Performance Enhancement of Polyamide Nanofiltration Membranes

Tailored design of high-performance nanofiltration membranes that can be used in a variety of applications such as water desalination, resource recovery, and sewage treatment is desirable. Herein, we describe the use of layered double hydroxides (LDH) intermediate layer to control the interfacial polymerization between trimesoyl chloride (TMC) and piperazine (PIP) for the preparation of polyamide (PA) membrane. The dense surface of LDH layer and its unique mass transfer behavior influence the diffusion of PIP, and the supporting role of the LDH layer allows the formation of ultrathin PA membranes. By only changing the concentration of PIP, a series of membranes with controllable thickness from 10 to 50 nm and tunable crosslinking-degree can be prepared. The membrane prepared with a higher concentration of PIP shows excellent performance for divalent salt retention with water permeance of 28 Lm⁻² h⁻¹ bar⁻¹, high rejection of 95.1 % for MgCl₂ and 97.1 % for Na₂SO₄. While the membrane obtained with a lower concentration of PIP can sieve dye molecules of different sizes with a flux of up to 70 Lm⁻² h⁻¹ bar⁻¹. This work demonstrates a novel strategy for the controllable preparation of high-performance nanofiltration membranes and provides new insights into how the intermediate layer affects the IP reaction and the final separation performance.     

Synthesis and in Vitro Cytotoxicity of a Novel Conjugate of Polyamide and Phospholipid

Small molecules with the ability to target predetermined sequences of DNA would be valuable tools in molecular biology and potentially in human medicine1-3. Synthetic polyamides consisting of N-methylpyrrole (Py), N-methylimidazole (Im) have received spec…     

Studies on Molecular Composites of Polyamide 6/Polyamide 66

Summary: A series of molecular composites of PA 6/PA 66 was synthesized via in situ polymerization. The impact resistance of PA 6 was improved dramatically by incorporating a minor amount of PA 66 (2–10 wt.‐%), without decreasing the tensile strength. Inserting PA 66 macromolecules at a molecular level into a PA 6 matrix may interfere with the arrangement of the hydrogen bonds of PA 6, in turn changing the crystalline structure and impeding the crystallization of PA 6.

SEM micrograph of the fractured surface of a PA 6/PA 66 composite containing 10 wt.‐% PA 66.     

Synthesis and properties of new fluorinated polyarylates derived from 1,1-bis(4-hydroxyphenyl)-1-phenyl-2,2,2-trifluoroethane and aromatic diacid chlorides

A new series of fluorine-containing polyarylates were synthesized by interfacial or high-temperature solution polymerization of 1,1-bis(4-hydroxyphenyl)-1-phenyl-2,2,2-trifluoroethane with six aromatic diacyl chlorides. These polyarylates had inherent viscosities ranging from 0.47 to 1.37 dl/g that corresponded to weight-average and number-average molecular weights (by gel permeation chromatography) of 35,800-72,400 and 30,700-67,700, respectively. All polymers were highly soluble in a variety of solvents, and could afford tough, transparent, and colorless films via solution casting. The glass-transition temperatures of the polymers ranged from 209 to 271 °C. All of them did not show significant decomposition below 450 °C in both nitrogen and air atmospheres.     

Synthesis and Magnetic Properties of Polyamide Complex Containing Bithiazole Moieties

A new polyamide containing bithiazole moieties （PTA） was synthesized by the polycondensation of 2, 2＇-diamino-4, 4＇-bithiazole （DABT） and oxalyl chloride. The polymer complex was prepared from PTA and NdC13 in DMSO. They were characterized through IR and elemental analysis. The preliminary magnetic properties of the complex PTA-Nd^3＋ was investigated, it was found that the material is a ferromagnet at low temperature.     

聚苯基膦酸二苯偶氮酯阻燃剂的合成与表征

为了解决高分子材料的耐燃性问题,阻燃剂的研究越来越受到广泛重视．聚膦酸酯类化合物是一类重要的膦系阻燃剂［１～４］,与传统的非聚合型阻燃剂相比,这种阻燃剂具有阻燃效果好、低烟低毒、与聚合物基材相容性好、耐迁移、耐挥发、阻燃效果持久等优点,成为阻燃剂研究...     

氧化石墨烯增容尼龙6/聚苯乙烯共混体系的研究

氧化石墨烯(GO)亲水性的边缘和疏水性的中间片层使其具有两亲特性.利用GO的这种特性,将其加入尼龙6(PA6)/聚苯乙烯(PS)的共混体系,以提高PA6和PS的相容性.通过两步法制备了PA6/PS/GO共混物,研究了GO对PA6/PS共混材料结构形态与力学性能的影响,并对其增容机理进行了探讨.扫描电镜(SEM)结果表明,添加GO后,共混材料的分散相尺寸明显变小,分散更为均匀,少量的GO即可达到良好的增容效果.动态力学性能(DMA)测试进一步证明了GO对PA6/PS共混物具有一定的增容性.理论计算也表明PS/GO共混物和PA6具有更接近的表面自由能和较低的界面自由能.添加GO后共混物材料的拉伸性能和韧性明显提高.GO添加量为0.1 wt％时,共混材料的断裂伸长率较未添加GO的共混材料提高了170％,断裂能也提高了近240％.     

Synthesis and Characterization of Poly(ether amide)s Containing Phthalazinone Moieties

Soluble aromatic polyamides containing phthalazinone moieties were prepared. Those polymers were obtained from the solution polymerization of a new diacid containing phthalazinone moieties with various diamines. The new monomer, 2-(4-carboxyphenyl)-4-(4-carboxyphenoxy)phenyl-1(2H)phthalazinone(Ⅳ) was synthesized in a two-step reaction sequence. 2-(4-Cyanophenyl)-4-(4-cyanophenoxy)phenyl-1(2H)phthalazinone (Ⅲ) was prepared via the condensation reaction of 4-(4-hydroxyphenyl)-1(2H)phthalazinone (Ⅰ) with p-chlorobenzonitrile (Ⅱ). After (Ⅲ) was hydrolyzed, (Ⅳ) was acquired. The synthesized polyamides were characterized by means of viscosimetry, DSC, FT-IR, 1H NMR and EA. The polyamides have a high glass transition temperature which can be as high as 316 ℃. The polyamides also have good solubilities in some organic solvents.     

Molecular Weight Characterization and Structural Properties of Controlled Molecular Weight Dextrans Synthesized by Acceptor Reaction using Highly Purified Dextransucrase

ABSTRACT

Controlled molecular weight dextrans were synthesized using a highly purified dextransucrase from Leuconostoc mesenteroides NRRL B-512F in a multi-step process. Maltose was used as acceptor for the first reaction step. The purified product obtained at a given reaction step was used as acceptor for the next reaction step. Dextrans of molecular weights ranging from 1,000 to 100,000 were thus obtained with a good yield (80 %). After purification, the molecular weight distribution of the products was characterized using size exclusion chromatography coupled with low angle laser light scattering (LALLS). Polydispersity of the products was shown to be similar to that of commerical dextrans.

¹³C NMR spectra and enzymatic hydrolysis data are consistent with the fact that the enzymatically synthesized dextrans are essentially composed of α(1->6) linkages. It was observed that controlled molecular weight dextrans were less branched than commercial products obtained by acidic hydrolysis of high molecular weight dextrans.