高分子共混物增容用反应性高分子

多相高分子共混物的研究已成为开发新型高性能高分子材料的重要途径之一。然而，简单的高分子共混物通常具有较低的力学性能和不稳定的形态，因此，高分子共混物的增容是很必要的。传统的增容方法是加入嵌段或接枝共聚物作为增容剂，然而，共混过程中通过反应性高分子就地形成增容剂的方法越来越受到重视。本文综述了用于高分子共混物增容的反应性高分子的类型、制备方法、应用体系及共混过程中所进行的化学反应。用于高分子共混物增     

Living functionalization of polymethacrylates by group transfer polymerization (GTP) using low ceiling temperature monomers

A living functionalization method for group transfer polymerization (GTP) has been developed for poly(alkyl methacrylates) using the sterically hindered monomer, methyl-2-phenylpropenoate (MPHA). The end-capping reactions of MPHA with living trimethylsilyl ketene acetal-ended poly(methyl methacrylate) (PMMA) chain ends have been systematically studied and characterized by size exclusion chromatography, vapor pressure osmometry, ultraviolet-visible, ¹H and ¹³C nuclear magnetic resonance spectroscopy. Although oligomerization of MPHA is observed at - 78° C, this is reversible and only monoaddition is observed at room temperature. In principle, various functional groups can be introduced into poly(alkyl methacrylates) via substituents on the aromatic ring of MPHA and related monomers. Amino-functionalized PMMA was prepared by end-capping reactions of living trimethylsilyl ketene acetal-ended PMMA with methyl E-3-(2-dimethylaminophenyl)-2-phenylacrylate.     

Synthesis of polyaniline using horseradish peroxidase immobilized on plasma‐functionalized polyethylene surfaces as initiator

The doping of semiconducting conjugated polymers (e.g., polyaniline, PANI) can result in the elimination of the bandgap, leading to high electrical conductivities (comparable to metals). Doped PANI is totally insoluble and thus nonprocessable, which considerably limits its practical applications. Synthesis of PANI using immobilized horseradish peroxidase (HRP) as a catalyst in aqueous solutions can open up additional possibilities for applications through the direct synthesis of controlled‐thickness PANI layers on various substrate surfaces. The RF plasma‐enhanced surface functionalization of polyethylene and the covalent immobilization of HRP are discussed, and the polymerization of aniline initiated by immobilized HRP is presented. The nature of plasma‐grafted surface functionalities on the substrate surfaces and the formation of PANI are demonstrated using X‐ray photoelectron spectroscopy and attenuated total reflectance Fourier transform IR spectroscopy. The molecular weight distribution of PANI is evaluated with gel permeation chromatography, and the activity of the immobilized enzyme is monitored using UV spectroscopy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 369–379, 2003     

聚烯烃接枝改性功能化的研究进展

综述了聚烯烃本体接枝改性和表面接枝改性在近两年来的研究进展 ,主要体现在接枝方法的优化、接枝物的扩充、接枝机理及反应动力学的研究以及接枝反应的控制、接枝物的高分子设计等方面     

Surface Functionalization of Single Superparamagnetic Iron Oxide Nanoparticles for Targeted Magnetic Resonance Imaging

Magnetic resonance imaging (MRI), a non‐invasive, non‐radiative technique, is thought to lead to cellular or even molecular resolution if optimized targeted MR contrast agents are introduced. This would allow diagnosing progressive diseases in early stages. Here, it is shown that the high binding affinity of poly(ethylene glycol)‐gallol (PEG‐gallol) allows freeze drying and re‐dispersion of 9 ± 2‐nm iron oxide cores individually stabilized with ≈9‐nm‐thick stealth coatings, yielding particle stability for at least 20 months. Particle size, stability, and magnetic properties of PEGylated particles are compared to Feridex, a commercially available untargeted negative MR contrast agent. Biotin‐PEG(3400)‐gallol/methoxy‐PEG(550)‐gallol stabilized nanoparticles are further functionalized with biotinylated human anti‐VCAM‐1 antibodies using the biotin–neutravidin linkage. Binding kinetics and excellent specificity of these nanoparticles are demonstrated using quartz crystal microbalance with dissipation monitoring (QCM‐D). These MR contrast agents can be functionalized with any biotinylated ligand at controlled ligand surface density, rendering them a versatile research tool.     

Fatty alcohols through hydroxylation of symmetrical alkenes with selenium dioxide/tert.-butylhydroperoxide

Several symmetrical alkenes were reacted with the selenium dioxide/tert.-butylhydroperoxide system to give three hydroxylated products each. These products were those of allylic mono- and dihydroxylation (meso andthreo dihydroxy compounds) of the double bond. Some dihydroxy products were hydrogenated to give saturated 1,4-diols. The compounds were characterized by nuclear magnetic resonance. The products have potential for application in commercial products, such as biodiesel, lubricants, greases, and cosmetics.     

Lignin–polypropylene composites. II. Plasma modification of kraft lignin and particulate polypropylene

Indulin kraft lignin and polypropylene were subjected to plasma treatments in a rotating electrodeless plasma reactor at 13.56 MHz radio frequency, with the goal of improving the strength properties of the composites made from these materials. It was shown that efficient surface modification could be achieved by these plasma treatments, avoiding long reaction times and large volumes of reactants for modification by conventional wet chemistry. SiCl₄‐plasma treatments of lignin at 100 and 200 W resulted in silicon implantation in the range of 4–10% that depended on the treatment time. However, the effect of power in the treatments was minimal, given that changes in silicon implantation were not observed for changes in this parameter. SiCl₄‐plasma treatment of polypropylene at 80 W, 1 and 10 min, resulted in silicon implantation in the order of 10–15%, for the two different treatment times, showing that low power and short treatment times were sufficient to significantly alter the polypropylene surface. However at high power (250 W), the longer treatment time of polypropylene apparently led to formation of oligohalosilanes. Other plasma treatments in the rotating reactor such as plasma‐induced copolymerization of acryloyl chloride on both lignin and polypropylene, and plasma‐state polymerization of acryloyl chloride on polypropylene under pulsing conditions, resulted in thin film depositions. Evaluation of composites from these treated materials is described in the next contribution (Part III) from this series. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1920–1926, 2004     

Primary amine functionalized polystyrenes by atom transfer radical polymerization

Primary amine functionalized polystyrenes were prepared in quantitative yields by atom transfer radical polymerization using the adduct of 1‐(bromoethyl)benzene with 1‐(4‐aminophenyl)‐1‐phenylethylene as initiator for styrene polymerization in the presence of a copper(I) bromide/N,N,N′,N′,N″‐pentamethyldiethylenetriamine catalyst system. The polymerizations proceeded via a controlled free radical polymerization process to afford quantitative yields of the corresponding primary amine functionalized polystyrenes with predictable molecular weights (M_n = 2 × 10³ to 10 × 10³ g mol^?1), relatively narrow molecular weight distributions (M_w/M_n = 1.03–1.49), well defined chain‐end functionalities and initiator efficiencies as high as 0.92. The polymerization process was monitored by gas chromatographic analysis. The primary amine functionalized polymers were characterized by thin layer chromatography, size exclusion chromatography, potentiometry and spectroscopy. Experimental results are consistent with quantitative functionalization via the 1,1‐diphenylethylene derivative. Polymerization kinetic measurements show that the polymerization reaction follows first order rate kinetics with respect to monomer consumption and the number average molecular weight increases linearly with monomer conversion. © 2003 Society of Chemical Industry     

Ti-ZSM-5沸石的合成及表征

用水热晶化法,在不同碱性介质中成功地合成了Ti-ZSM-5沸石。对其结构进行了XRD、IR、SEM、TG-DTA及~(29)Si MASNMR表征,肯定了所合成的沸石为ZSM-5型,且钛原子已进入了沸石骨架,而且该沸石骨架热稳定性超过1473K。发现碱金属阳离子阻碍钛原子进入沸石骨架。从氯丙烯与H_2O_2的环氧化结果看,Ti-ZSM-5沸石对烯烃环氧化过程有很好的催化作用,环氧产物的收率高。     

Co3O4纳米线的模板合成及其电化学性能

以三甲基氯硅烷(TMCS)和氨丙基三乙氧基硅烷(APTS)进行外内表面修饰的SBA-15为模板,Co(NO3)2·6H2O为原料,成功地合成了Co3O4纳米线.采用透射电子显微镜(TEM)、N2吸附-脱附、X-射线衍射(XRD)等多种手段对修饰后的SBA-15和Co3O4纳米线进行表征.结果证明:内外表面修饰后的SBA...