THE ADHESIVE CAPACITY OF STARCH GRAFT COPOLYMERS TO POLYESTER/COTTON FIBER

The advantages of using starch graft copolymers as warp sizes in textile were briefly discussed, and the factors of affecting adhesive capacity to the fiber were analysed. By using eerie ammonium nitrate as an initiator under nitrogen atomosphere, a number of vinyl and/or acrylic monomers such as acrylic acid, acrylamide, methyl acrylate, ethyl acrylate, butyl acrylate, hydroxyethyl acrylate, methyl methacrylate, butyl methacrylate, vinyl acetate and the combinations among them were graft copolymerized respectively onto granular corn starch in aqueous dispersion. The adhesive capacity of these starch graft copolymers to polyester/cotton fibers was evaluated by a slightly sized rovings according to V. K. Aggarwal's method which measures the breaking strength and elongation of the rovings impregnated with the size paste. The influences of the monomers and their combinations, the grafting technological processes and the pretreatment methods before graft copolymerization upon adhesive capacity have been dis     

Starch-g-poly (vinyl alcohol)as Compatibilizer for Reducing the Phase Separation Rates of Polyvinyl Alcohol/Cornstarch Pastes

Starch-g-poly(vinyl alcohol) as a compatibilizing agent for reducing the phase separation rates of polyvinyl alcohol/starch pastes has been investigated by blending and dissolving the two polymers in distilled water. The separation rates were quantitatively evaluated by the term of initial demisting time. The grafted starches, with a series of grafting ratios, were prepared by grafting a number of vinyl acetate onto granular cornstarch in aqueous dispersion and then alcoholating in methanol. It was found that the addition of small amounts of starch- g-poly ( vinyl alcohol) in the size compositions can effectively decrease the separation rates of the blended pastes in comparison to pure starch/PVA ones. Moreover, the influence of the grafting ratio, starch content, and PVA variety on the separation rates was also studied.     

SYNTHESIS AND SIZING PROPERTIES OF GRAFT STARCHES AS WARP SIZING MATERIALS FOR POLYESTER/COTTON BLEND SPUN YARN

Grafting a number of monomers such as acrylic acid, acrylamide, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, butyl methacrylate and vinyl acetate onto granular corn starch was carried out respectively in aqueous dispersion by using cerie ammonium nitrate as an initiator under nitrogen atmosphere. Conversion of monomer, grafting ratio and grafting efficiency were measured by the method of combining the chemical quantitative analysis with the weight. The adhesive power of the starch graft copolymers to polyester/cotton fiber was evaluated by measuring the breaking strength and elongation of the roving impregnated with the paste. The viscosity change of the size paste before and after grafting was studied. The mechanical properties of polyester/cotton fibre yarn sized by the graft starch were tested. The main conclusions are as follows: (1) monomers which were graft coplymerized onto starch have a significant influence upon the viscosity of the size paste; (2) the adhesive power of     

Preparation of New Chiral Ferroceny Phosphine Ligands and Their Application to Organic Synthesis

1 Results The unique structure of chiral ferrocenes allows one to design a variety of chiral phosphine ligands,which are useful tools for metal catalyzed asymmetric reactions.Although some useful chiral ferrocenyl phosphine ligands have already been reported,it is still an challenging subject tocreate new ferrocenyl phosphine ligands in order to cover asymmetric reactions in which conventional ligands do not effectively work[1].We happned to discover that 1,5-dilithiation of o-TMS blocked ferrocene 1 proceeded unexpectedly to give the 1,5-dilithiated ferrocene 2 which was isolated as 1,5-diiodide 3 by trapping with iodine and subsequent removal of TMS group. The 1,5-diiodide 3 was converted into Taniaphos 4 by sequence of re-dilithiation and trapping with Ph2PCl[2].     

Designing Cyclopentapeptide Inhibitor of Neuraminidase H5N1 Virus Through Molecular and Pharmacology Simulations

Highly Pathogenic Avian Influenza(HPAI) H5N1 has attracted much attention as a potential pandemic virus in humans, which makes death inevitable in humans. Neuraminidase(NA) has an important role in viral replication. Thus, it is an attractive target when designing anti-influenza virus drug. However, evolving viruses cause some anti-viral drugs to be ineffective, as they show resistance to them. Selection of peptides as drug candidates is important for the peptide-receptor activity and good selectivity. Cyclic bonds in the peptide ligand design aim to improve the stability of the system and remove the obstacles in drug metabolism. The design is based on the polarity of the ligand and amino acid residues in the active site of NA. The results are 4200 cyclic pentapeptides as potential lead compounds. Docking simulations were conducted using MOE 2008.10 and were screened based on the value of the binding energy(?Gbinding). ADME-Tox prediction assay was conducted on the selected ligands.Intra- and inter-molecular interactions, as well as changes in the form of bonds, were tested by molecular dynamics simulations at temperatures of 310 K and 312 K. The results of the docking simulations and toxicity prediction assay show that there are two ligands that have a residual interaction with the target protein: CLDRC and CIWRC. These two ligands have ?Gbindingvalues of –40.5854 and –39.9721 kcal/mol(1 kcal/mol = 4.18 k J/mol). These ligands are prone to be mutagenic and carcinogenic, and they have a good oral bioavailability. The results show that the molecular dynamics of both ligand CLDRC and CIWRC are more feasible at the temperature of 312 K. At the end,both CIWRC and CLDRC ligands can be used as the drug candidates against H5N1 virus.     

Isolation and Characteristics of New Heterotrophic Nitrifying Bacteria

The study presented the method for isolating the heterotrophic nitrifiers and the characterization of heterotrophic nitrification. When influent Ammonia nitrogen concentration was 42. 78-73. 62 mg/L. The average ammonia nitrogen removal rate was 81,32% from the bio-ceramics reactor. Sodium acetate and ammonium chloride were used as carbon and nitrogen source. The COD removal rates by microorganisms of strain wgy21 and wgy36 were 56.1% and 45.45%, respectively. The TN removal rates by microorganisms of strain wgy21 and wgy36 were 65.85%and 67. 98%, respectively. At the same time, the concentration of ammonium nitrogen was with the removal rates of 75.25% and 84.96%, and it also had the function of producing NO2-N. Sodium acetate and sodium nitrite were used as carbon and nitrogen source. Through the 12days of the aerobic culture, the COD femoral rates by microorganisms of strain wgy21 and wgy36 were 29.25%and 22.08%, respectively. NO2-N concentration decreased slowly. Comparison, similarity of wgy21 and many Acinetobacter sp. ≥99%, similarity of wgy36 and many Acinetobacter sp. ≥99%. Refer to routine physiological-biochemical characteristic determination, further evidences showed that wgy21 and wgy36 belong to Acinetobacter sp.,respectively.     

Nerve growth factor activity of several immunal related serine proteases

Rabbit was immuned by the previously purified protein with high nerve growth factor (NGF) bioactivity (NGF_like protease) from \%Agkistrodon halys Pallas\% and the antisera were collected. The polyclonal antibodies were tentatively purified and then used as ligands of an affinity column. The \%A.h.Pallas\% crude venom was fractionated by this affinity column and then by Mono Q on fast protein liquid chromatography (FPLC). As a result, fraction Ⅱ and fraction Ⅲ were purified respectively, whose N_terminal amino acid sequences show high homology with the serine proteases in snake venoms, as well as the previous NGF_like protease. However, they possessed different levels of NGF bioactivity. The NGF activity of the previous NGF_like protease is equivalent to that of NGF, while the activity of fraction Ⅱ seems relatively low in contrast to fraction Ⅲ which had no NGF activity.     

Preparation of CdTe nanocrystal-polymer composite microspheres in aqueous solution by dispersing method

Highly fluorescent CdTe nanocrystals were synthesized in aqueous solution, and then processible CdTe nanocrystal-polymer composites were fabricated by coating the aqueous nanocrystals with copolymers of styrene and octadecyl-p-vinyl-benzyldimethylammonium chloride (SOVDAC) directly. A dichloromethane solution of CdTe nanocrystal-polymer composites was dispersed in the aqueous solution of poly (vinyl alcohol) (PVA) generating highly fluorescent microspheres. Experimental parameters such as the concentration of nanocrystal-polymer composites, the concentration of PVA, and stirring speed which had important effect on the preparation of the microspheres were investigated in detail with fluorescent microscope characterization.     

Study on the Synthesis of γ-aminopropyltriethoxysilane Modified Montmorillonite Supported Hydroxysulfonamide

1 Results A novel chiral hydroxysulfonamides,which have hydroxysulfonamide structures,are designed and synthesized from natural camphor.It has been studied for the application as chiral catalyst.This class of ligands can be used in many reactions that are catalysed by amino alcohol ligands.In this paper,we prepared a novel chiral hydroxysulfonamides by immobilization of on MMT modified by γ-aminopropyltriethoxysilane.The MMT was first pretreated with hydrochloric acid according to a reported patent[1]. ...     

Preparation and Performance of Bipolar Membranes with Liquid Ion-Exchange Medium

The current density is rather low in solid bipolar membranes, because the water transfer rate is relatively slow across solid bipolar membranes made of solid ion-exchange materials. This paper describes the use of polymer solutions, such as phosphatic poly(vinyl alcohol) solution, poly(acrylic acid) solution and poly(vinyl alcohol) solutions with dispersed cation/anion-exchange resin particles to prepare bipolar membranes. The 0. 1 mol/L NaOH and the 0.05 mol/L H2SO4 were used to test the performance of the bipolar membranes. For a fixed liquid layer thickness, both the current density and the selectivity increase with the concentration increase of a polyelectrolyte solution. The maximum current density measured in the experiment was 1497A/m^2 with a selectivity of 96.8%.     

Asymmetric synthesis of α-aminophosphonates by means of direct organocatalytic three-component hydrophosphonylation

The direct asymmetric three-component reaction of an aromatic (or cinnamic) aldehyde, an amine and a phosphite was investigated by employing chiral Brønsted acid. In general, modest to good enantioselectivities (31%–87% ee) could be obtained in acceptable isolated yields (61%–91%) for a series of substrates.     

Enantioselective Chlorocyclization of Olefinic Amides with 1,3-Dichloro- 5, 5-Dimethylhydantoin (DCDMH) Catalyzed by (DHQD)<Subscript>2</Subscript>PHAL

An efficient catalytic asymmetric chlorocyclization of olefinic amides with 1,3-dichloro-5,5-dimethylhydantoin (DCDMH) using hydroquinidine 1,4-phthalazinediyl diether ((DHQD)₂PHAL) as organocatalyst has been developed. Series of chiral chloro substituted isobenzofuran-1(3H)-imine derivatives were obtained in good yields (up to 85%) and enantioselectivities (up to 70% ee).     

聚乙烯醇-b-聚苯乙烯嵌段星形聚合物的制备

通过CCl₄调聚反应制备出了末端带有氯原子的聚醋酸乙烯酯(PVAc),进一步引发苯乙烯原子转移自由基聚合得到聚醋酸乙烯酯-b-聚苯乙烯嵌段共聚物(PVAc-b-PSt),此嵌段共聚物与偶联剂二乙烯基苯反应后醇解,得到了聚乙烯醇-b-聚苯乙烯星形嵌段共聚物(PVA-b-PSt)_n。分别以GPC,¹H-NMR及FT-IR对各步反应产物进行了表征,聚醋酸乙烯酯比较完全地引发苯乙烯进行原子转移自由基聚合(ATRP),聚合物相对分子质量与单体转化率呈线性关系,证明聚合过程为活性聚合;以二乙烯基苯偶联PVAc-b-PSt,得到了星形共聚物,并出现了星形共聚物之间的偶合;醇解过程进行比较完全,¹H-NMR及FT-IR谱图表明酯基团已较完全地转变成羟基。     

手性β-氨基醇催化的芳香醛对映选择性炔化反应

 手性β-氨基醇是不对称催化反应中应用最为广泛的手性配体之一.以L-苯丙氨酸为原料简捷合成的手性β-氨基醇L^*为手性配体,对不同取代芳香醛的对映选择性炔化反应进行了研究,结果表明其对该反应具有一定的不对称催化活性,光学收率(e.e值)最高达78.9%.     

两相体系中长链烯烃氢甲酰化反应研究--膦配体对活性和选择性的影响

在温和条件下合成了两种水溶性膦配体：三(4-甲氧基-3-磺酸钠苯基)膦(简称：4-MOTPPTS)和三(2-甲氧基-3-磺酸钠苯基)膦(简称：2-MOTPPTS)．在水／有机两相体系中，以RhCl(CO)(TPPTS)2为催化剂前体，考察了4-MOTPPTS和2-MOTPPTS作为配体时，膦／铑摩尔比、反应温度和压力变化对1-十二烯氢甲酰化反应催化性能的影响．结果表明，与三(3-磺酸钠苯基)膦(简称TPPTS)相比，在苯环上引入甲氧基后，其供电特性使催化剂对烯烃氢甲酰化反应的活性和生成醛的选择性不利，而邻位甲氧基的引入所造成的空间位阻，使2-MOTPPTS表现出较4-MOTPPTS更低的催化活性和选择性．但与相应的油溶性膦配体相比，对生成醛的选择性明显增加．     

功能化聚苯乙烯树脂负载钯催化剂在聚酮合成中的应用

采用苯乙烯与二乙烯基苯交联合成聚苯乙烯树脂微球,通过一系列反应后得到表面接枝双齿氮的功能化树脂微球.以负载有乙酸钯的功能化树脂微球组成的催化体系催化一氧化碳和苯乙烯共聚合成聚酮.利用红外光谱和扫描电镜对树脂负载催化剂及聚合产物进行了表征.研究了催化体系中各组分用量及反应时间对共聚反应的影响.结果表明,树脂负载催化剂对聚酮合成反应具有较好的催化性能:当树脂用量为0.5 g、乙酸钯为22.4 mg时,聚酮产量达8.6606 g.     

两相体系中含氮双齿膦配体对1-十二烯氢甲酰化反应的影响

含氮双齿膦配体(Ph2PCH2)2NCH2CH2OCH2CH2NHCH2CH2PO3Na2(以A表示)在1-十二烯的氢甲酰化反应中的实验结果表明双膦配体的螯合作用降低了催化活性和有利于直链醛的生成.A与水溶性催化剂RhCl(CO)(TPPTS)2在合成气氛下发生配体交换后,形成配合物HRh(CO)(A)(TPPTS),其催化活性比单膦-铑配合物的催化活性更低.又由于双膦与铑配位后形成的络合物中铑的配位空间更拥挤,因此1-十二烯的端碳原子更容易与铑中心络合配位,形成直链烷基-铑络合物,使得产物醛中直链醛的含量增大.     

Chiral <Emphasis Type="Italic">N</Emphasis>-formyl amino alcohol as Lewis basic organocatalyst for enantioselective hydrosilylation of ketimines

Easily accessible (1R,2S)-1,2-diphenyl-2-formamidoethanol has been developed as an effective Lewis base catalyst in the enanti-oselective hydrosilylation of ketimines, affording high isolated yields (up to 94%) and moderate to high enantioselectivities (up to 82% ee) for a broad range of ketimines.     

过渡金属/磷配体络合物催化不对称氢甲酰化研究进展

手性醛是合成生物活性物质如药物活性分子等的重要中间体,及各种高附加值精细化学品如香料等的起始原料,潜手性烯烃及其衍生物的不对称氢甲酰化是合成光学活性醛的重要方法之一.在烯烃的不对称氢甲酰化中铑与膦形成的催化体系因活性高、选择性好等优点而被广泛应用.主要介绍了近年来几类新型手性磷配体与铑形成的络合物催化剂在不对称氢甲酰化反应中的应用研究结果,如Rh/手性双-3,4-二氮磷杂环戊烷配体(S,S,S)-Bisdiazaphos和(R,S)-NEt-Yanpho络合物催化剂等.     

脂肪酶催化拆分2-氯-1-苯乙醇

手性2-氯-1-苯乙醇这一关键的药物中间体,已被酶法合成。经过筛选多种脂肪酶,一种新的商业化的来自Pseudomonas cepacia固定化脂肪酶PS IM,表现出最高的活力。同时首次发现小麦胚芽脂肪酶（WGL）具有与其他脂肪酶相反的立体选择性。并系统探讨了溶剂体系,温度以及水活度对PS IM催化拆分2-氯-1-苯乙醇的影响。最终发现在正己烷体系,35℃和水活度0.69时,获得最好的分离效果,能同时得到两个高纯度的对映体（eep 99%,ees 99%）。PS IM在经过5次重复反应之后的活力约保留了85%。