A Novel Approach for Observing Morphology of Polypropylene under Ultrasonic Vibration by SALS

In this paper, a set of ultrasonic vibration device connecting with small angle light scattering(SALS) for in-situ observing phase-transition of polymer under ultrasonic vibration was established. The experiments for verifying polypropylene(PP) indicated that ultrasonic vibration resulted in the decrease of the crystallization rate and made PP crystallizable at low temperature.     

Surface Modification of Polypropylene by Ethylene Plasma and Its Induced β-Form in Polypropylene

This study aims to investigate the chemical structure and morphology of plasmapolymers produced by deposition of ethylene on the surface of polypropylene. The deposition films(sediments) of ethylene plasma on the surface of polypropylene are nonuniform, and the characterization results indicate the existence of hydroxyl groups and aldehyde(or ketone) groups in the sediments. The sediment of ethylene plasma on the polypropylene surface could induce the growth of β-form crystals in the surface layer of polypropylene.     

Structure and Properties of β-Polypropylene Reinforced by Polypropylene Fiber and Polyamide Fiber

Matrix/fiber composites of β-form isotactic polypropylene(iPP) matrix and α-iPP or PA6 fibers were prepared by laminating technique under different preparation temperatures. The mechanical properties and interfacial morphologies of these composites were studied by tensile test, optical microscopy and scanning electron microscopy, respectively. The experimental results show that the tensile yield load and tensile modulus of β-iPP/PA6 matrix/fiber systems increased significantly at the expense of elongation at break. These mechanical properties show essentially no dependence on the sample preparation temperature. On the other hand, the mechanical properties of iPP matrix/fiber single polymer composites depend strongly on the sample preparation temperature. At low sample preparation temperature, e.g., 172 ℃, the solid α-iPP fiber induces α-iPP crystallization, leading to the formation of α-iPP transcrystalline layer around the fiber. This results in a remarkable increment of the tensile yield load and tensile modulus. The elongation at break is also much better than that of the iPP/PA6 matrix/fiber system. It reflects a better interfacial adhesion of the single polymer composite compared with the iPP/PA6 composite. At higher sample preparation temperature, e.g., 174 ℃ or 176 ℃, the partial surface melting of the oriented fiber allows interdiffusion of iPP molecular chains in the molten fiber and matrix melt. The penetration of matrix chains into the molten iPP fiber results in some iPP molecular chains being included partially in the recrystallized fiber and the induced β-transcrystalline layers. This kind of configuration leads to an improvement of interfacial adhesion between the fiber and matrix, which causes a simultaneous increase of the tensile yield load, tensile modulus and elongation at break of β-iPP.     

Preparation and Characterization of CuInS2 Thin Films for Solar Cells by Chemical Bath Deposition

Recent years, chalcopyrite semiconductors have been successfully applied as absorber layers for polycrystalline thin-film solar cells. Among the ternary compound semiconductors, CuInSz thin films with a direct bandgap of about 1.50eV and a large absorption coefficient in the range of 10^4-10^5cm^-1[1] are one kind of the most promising optical absorbers for high efficiency thin film solar cells.     

Characterization of the Nanoscale Microstructure of an Immersion Silver on Sputtered Copper

1 INTRODUCTION Silver and its compounds have received much attention due to their current and potential applica- tions in many areas[1, 2]. As a metal with the highest electrical and thermal conductivities, silver was one of the most important noble metals used in electrical industries in the last century. Several decades ago, however, the development of silver application in electronic area seemed not so quick. The fear for some undesirable phenomena involving silver, like “electrochemi…     

Structural Characterization of an Exopolysaccharide from the Myxobacterium Sorangium Cellulosum NUST06

The large amounts of extracellulular matter produced by myxobacteria were composed of EPS and proteins that demonstrated as required factor for cell-cell cohesion1. There were few reports on the structure and bioactivities of the EPS in myxobacteria and all focus on myxobacterial extracellular matter were their role in myxobacteria social interactions2. Studies of the chemical structure of these molecules, constituent identification, and chemical and physical properties are essential for u…     

Synthesis,Characterization,Thermal Decomposition Mechanism and Non—Isothermal Kinetics of the Pyruvic Acid—Salicylhydrazone and Its Complex of Prasseodymium（Ⅲ）

The pyruvic add‐salicylhydrazone and its new complex of Pr(III) were synthesized. The formulae C₁₀H₁₀N₂O₄ (mark as H₃L) and [Pr₂(L)₂(H₂O)₂]·3H₂O (L= the triad form of the pyruvic acid‐salicylhydrazone [C₁₀H₇N₂O₄]^3‐) were determined by elemental and EDTA volumetric analysis. Molar conductance, IR, UV, X‐ray and ¹H NMR were carried out for the characterizations of the complex and the ligand. The thermal decompositions of the ligand and the complex with the kinetic study were carried out by non‐isothermal thermogravimetry. The Kissinger's method and Ozawa's method are used to calculate the activation energy value of the main step decomposition. The stages of the decompositions were identified by TG‐DTG‐DSC curve. The non‐isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by comparing the kinetic parameters.     

Synthesis and Characterization of Rh—Co Butterfly Clusters Capped by Functionally Substituted 1—Alkynes

1INTRODUCTIONThemixed-transition-metalclustershavehighpotentialtoserveasefficientcatalystsforavarietyofhomogeneouscatalyticreactionsaswellasuniquereagentsfororganicsyntheses[1].Ithasbeenreportedthatthereactionsof[Rh2Co2(CO)12]withseveralalkynestogiveRh-Comixed-metalbutterflyclusters[1～4].Inaddition,thereactionofsilylformylationof1-hexynewiththehydro-formylationofcyclohexene,1-penteneandstyrenehavealsobeeninvestigatedbyusing[Rh2Co2(CO)ascatalyst[5].Inordertogainmoreunderstandingaboutt…     

Synthesis and Characterization of Linked Clusters Capped by Alkylidyne

1 INTRODUCTION Constructing higher nuclearity clusters with well-defined dimensions and structures provide a rather active field of chemistry with potential applications in areas including nanotechnology, molecular recognition and catalysis[1~4]. A continuing effort has been directed toward developing a better methodology for systematic synthesis of supracluster compounds through molecular design [5,6]. On the basis of extensive investigation on the metal exchange reaction in cluster com…     

pH-Sensitive Wettability Induced by Topologicaland Chemical Transition on the Self AssembledSurface of Block Copolymer简

pH-sensitive wettability of polystyrene-b-poly（4-vinylpyridine） （PS-b-P4VP） self assembled films, exhibiting superoleophobicity under water and hydrophilicity at low pH value, and oleophobicity under water and hydrophobicity at neutral condition, has been realized. The wettability properties resulted from the surface topological and chemical transition, which were confirmed by in situ AFM measurements under water at different pH. At low pH, P4VP chains, which were confined in the hexagonal-packed nanodomains, got protonated into a swollen state, while at high pH, P4VP chains were deprotonated into a collapsed state. The reversible protonation/deprotonation procedure on the molecular scale leads to surface topological and chemical transition, thereby pH-sensitive wettability.     

拉伸和退火诱导间同立构聚丙烯的构象转变

90年代以来,随着锆和铪茂金属催化剂的出现,人们已能得到高立构度的sPP^[1].由于sPP具有无毒,软硬适中,尤其是在高度结晶时仍具有很好的透明性等优点,越来越受到人们的广泛注意.     

Polymorphic Behavior of Syndiotactic Polypropylene Induced by Heat Treatment

The polymorphic behavior of syndiotactic polypropylene (s-PP) crystallized from the melt under different conditions was investigated by means of WAXD and DSC. The isothermal melt crystallization of s-PP proceeded in form I at tc≥ 110℃ and in form Ⅱ at tc≤110 ℃ s-PP crystallized nonisothermally from the melt was the mixture of forms and . With increasing the cooling rate (a), the content of form increased, and the content of form decreased. On heating, at 10 K/min, of quenched s-PP, it crystallized in form at t≤70 , continuing heating resulted in form form transition, which was an endothermal process.     

Preparation of Intumescent Flame Retardant Polypropylene composite through Solid State Mechanochemical Method

Polypropylene (PP), with characteristics of good mechanical properties, good resistance to water and low cost, has been widely used in many fields such as building, transport, furniture and electrical industries. However, a fateful drawback of polypropylene is its high flammability,restricting its wider applications. Addition of flame retardants is an effective way to improve its flame retardancy. An effective halogen-free flame retardant system used is the mixture of melamine, ammounium phosphate and pentaerythritol (intumescent flame retardant). But how to enhance the dispersion of this mixture in polypropylene matrix is a big problem. A self-made mechanochemical reactor, pan type milling equipment, can exert strong shear and squeeze forces,and has good mixing function. As a result, a uniform dispersion of flame retardants in the polymer matrix can be expectably obtained by using this equipment.In this paper, flame-retarded Polypropylene (PP) composites with intumescent flame retardant (IFR) were prepared via solid state mechanochemical method (pan-mill) and conventional method (twin-roll masticator) respectively. Particle diameter analysis, melt flow index (MFI), differential scanning calorimetry (DSC) and scanning electronic microscopy (SEM) were used to characterize these composites, and the mechanical properties and flame retardancy were also determined. The experimental results showed that the blend of PP and IFR were effectively pulverized from 3～4 mm to less than 300i m under the strong shear forces of pan-mill. With increasing the milling cycles, the MFI value of IFR/PP blend decreased first and then increased. The mechanical properties and flame retardancy of IFR/PP blends prepared by solid state mechanochemical method were proved to be better than those prepared by conventional method because of the dispersing function of pan-mill.Also it was found that IFRs were the nucleating agent for PP and the crystallinity of PP increased first and then decreased with increasing the milling cycles.     

原生态聚丙烯等离子体处理接枝甲基丙烯酸甲酯

将等离子体接枝技术，用于原生态聚丙烯接枝甲基丙烯酸甲酯共聚物的合成。ＦＴ－ＩＲ证明所得产物为接枝共聚物，研究了不同等离子体处理功率、时间，不同接枝聚合反应时间、温度对接枝的影响，以及稀释剂、聚丙烯粒度对接枝的影响。结果表明，接枝过程中有自动加速现象，稀释剂亦使接枝有加速效应。接枝过程为扩散控制过程。     

聚丙烯表面光氧化的XPS研究

利用X射线光电子能谱(XPS)研究了光氧老化的聚丙烯(PP)表面的化学结构和组成变化。结果表明:(1)在受光氧老化的PP表面上形成了C-O、C=O及O-C=O官能团;(2)低分子抗氧剂在PP表面发生富集;(3)表面Ols/Cls强度比率可以较好地与冲击强度保留率相关联。     

原生态聚丙烯等离子处理接枝甲基丙烯酸甲酯

将等离子体接枝技术，用于原生态聚丙烯接枝甲基丙烯酸甲酯共聚物的合成，ＦＴ－ＩＲ证明所得产物为接枝共聚物，研究了不同等离子体处理功率，时间，不同接枝聚合反应时间，温度对接枝的影响，以及稀释剂、聚丙烯粒度对接枝的影响，结果表明，接枝过程中有自动加速现象，稀释剂亦使接枝有加速效应，接枝过程为扩散控制过程。     

高熔体强度聚丙烯的制备与表征

高熔体强度聚丙烯（HMSPP）相比于普通聚丙烯具有优越的综合性能,其良好的加工性能使其具有广阔的应用前景,并成为许多国家近年来竞相开发的热点。本文从HMSPP的结构特点、制备方法、性能测试等方面总结了近年来的研究进展,着重介绍了反应器合成长链支化型高熔体强度聚丙烯（LCB-HMSPP）的方法以及其结构表征,并在总结国内外现状的基础上展望了高熔体强度聚丙烯的发展前景。     

马来酸酐功能化聚丙烯的研究进展

简要叙述聚丙烯功能化的目的,介绍马来酸酐接枝聚丙烯实现功能化的几种实施方法,功能化聚丙烯的结构与性能表征,以及该功能化产物的应用。     

Surface Modification and Characterization of Dichloromethane Plasma Treated Polypropylene Film

Surface of polypropylene (PP) film was modified in plasma of dichloromethane (CH₂Cl₂). The nature of surface modifications and formation of cross-linked layer due to plasma polymerization was studied by surface energy measurements and solubility test. Surface modification achieved by CH₂Cl₂ plasma was compared with the reported work on chloroform (CHCl₃) and carbontetrachloride (CCl₄) plasma modifications. Modified surface characterized by ATR-FTIR technique indicated formation of saturated and unsaturated cross-linked product. On the basis of relative intensity change of the specific bands, the site of attachment of chlorine on PP surface was investigated. Adhesive strength of modified film was measured by T-peel test method. Stability of modified surface was studied by measuring surface energy and peel strength after two months.