PS/PVC互贯大孔吸附树脂对脲酸的吸附研究

大孔球状PVC经苯乙烯的自由基互穿聚合反应改性得PS PVC大孔互贯树脂 ,再与有机胺反应制得了PS PVC互贯含氮大孔吸附树脂 .研究表明 ,所得吸附树脂对脲酸的吸附率可达 5 0 %以上 ,在清除体液中过量脲酸方面具有应用潜力 .同时对吸附树脂含氮量与吸附脲酸性能的关系以及其它因素的影响也进行了探讨     

Mechanism of adhesion of polyurethane/polymethacrylate simultaneous interpenetrating networks adhesives to polymer substrates

Polyether-based polyurethane/poly (methyl methacrylate-co-ethyleneglycol dimethacrylate) interpenetrating polymer networks [PU/P (MMA–co–EGDMA)-IPNs] were synthesized and used as adhesives to adhere vulcanized natural rubber (NR) and soft polyvinyl chloride (PVC). The structure and morphology of the IPN adhesives in bulk and near the adhesive/substrate interfaces were investigated. A new mechanism of adhesion called conjugate interpenetration of networks across interfaces, which is suitable for IPN adhesives and polymer substrates, was put forward. According to this mechanism, while forming simultaneous interpenetrating networks in the adhesive, the monomers in the IPN adhesive can permeate polymer substrates and polymerize in situ to form gradient IPNs, thereby producing conjugate three-component IPNs near the adhesive/substrate interfaces. It is the conjugate interpenetration of the networks across the interfaces that strengthens interfacial combination remarkably and results in high bond strength of IPN adhesives. © 1994 John Wiley & Sons, Inc.     

Toughness Behaviour of Vinylester/Epoxy Thermosets with Interpenetrating Network Structure

Vinylester/epoxy-based (VE/EP) thermosets of interpenetrating network (IPN) structure were produced by using a VE resin (bismethacryloxy derivative of a bisphenol-A type EP resin) and EP resins of aliphatic (Al-EP) and cycloaliphatic (Cal-EP) nature. Curing of the EP resins occurred either by an aliphatic (Al-Am) or a cycloaliphatic (Cal-Am) diamine compound. Dynamic mechanical thermal analysis (DMTA) and atomic force microscopy (AFM) suggested the presence of an interpenetrating network (IPN) in the resulting thermosets. AFM scans taken on the ion-etched surface of EP showed a featureless homogeneous structure. On the other hand, VE exhibited a two-phase microgel, whereas VE/EP a two-phase interpenetrating network (IPN) structure. Toughness was characterised by parameters of the linear elastic fracture mechanics, viz. fracture toughness (K_c) and fracture energy (G_c). Unexpected high K_c and G_c data were found for the systems containing cyclohexylene units in the EP network. This was attributed to beneficial effects of the conformational changes along the cyclohexylene linkages (chair/boat). The failure mode of the VE/EP thermoset combinations was studied by scanning electron microscopy (SEM) and discussed.     

Acrylonitrile Copolymerizations. VI. Influence of the Comonomer on the Intramolecular Cyclization Reaction

The intramolecular cyclization reaction involving the polymerization of cyano groups reported in a previous paper for the system acrylonitrile-vinyl chloride is studied for other comonomers with acrylonitrile including vinyl acetate, vinylidene chloride, butadiene, styrene, methyl acrylate, and methyl methacrylate. It is shown that the extent of the reaction is governed by the reactivity of the comonomer-unit ended radical, but the cyclization reaction cannot explain all the kinetic deviations observed.     

高分子阻尼涂料的研究进展

介绍了高分子阻尼涂料的阻尼机理和组成,以及阻尼涂料的高分子改性方法,包括共聚、共混和互穿网络(IPN)等以及国内外发展现状。重点介绍了目前通用的树脂基料和填料,详细介绍了互穿网络改性方法和乳液聚合物互穿网络,以及环境友好水性阻尼涂料的研究现状和发展。     

Influence of the type of epoxy hardener on the structure and properties of interpenetrated vinyl ester/epoxy resins

The morphology–toughness relationship of vinyl ester/cycloaliphatic epoxy hybrid resins of interpenetrating network (IPN) structures was studied as a function of the epoxy hardening. The epoxy was crosslinked via polyaddition reactions (with aliphatic and cycloaliphatic diamines), cationic homopolymerization (via a boron trifluoride complex), and maleic anhydride. Maleic anhydride worked as a dual‐phase crosslinking agent by favoring the formation of a grafted IPN structure between the vinyl ester and epoxy. The type of epoxy hardener strongly affected the IPN morphology and toughness. The toughness was assessed by linear elastic fracture mechanics, which determined the fracture toughness and energy. The more compact the IPN structure was, the lower the fracture energy was of the interpenetrated vinyl ester/epoxy formulations. This resulted in the following toughness ranking: aliphatic diamine > cycloaliphatic diamine ≥ boron trifluoride complex > maleic anhydride. For IPN characterization, the width of the entangling bands and the surface roughness parameters were considered. Their values were deduced from atomic force microscopy scans taken on ion‐etched surfaces. More compact, less rough IPN‐structured resins possessed lower toughness parameters than less compact, rougher structured ones. The latter were less compatible according to dynamic mechanical thermal and thermogravimetric analyses. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 5471–5481, 2004     

A study of three-layered latex interpenetrating polymer networks used as processing modifiers and impact modifiers of thermo-plastic resins

In this paper, the latex interpenetrating polymer network poly(n-butyl acrylate) polystyrene/poly(methyl methacrylate) (PBA/PS/PMMA, or PBSM) was synthesized by microagglomeration and three-stage emulsion polymerization. The initial poly(n-butyl acrylate) latex particle was agglomerated by methacrylic acid residue containing the polymer latex and then encapsulated by PS and PMMA. The polyblend of poly(vinyl chloride) (PVC) and PBSM (PVC/PBSM) was prepared by blending PVC and PBSM. The morphology and properties of the polyblend have been studied. Experimental results have shown that the processability and impact-resistance of PVC can be enhanced considerably by means of blending 6–20 per hundred resin (phr) PBSM. The three-layered latex interpenetrating polymer network is a promising modifier for rigid PVC (RPVC) manufactures.     

Radiation-induced grafting polymerization by the ionic mechanism

A technique of radiation-induced grafting under conditions of extreme drying of monomers has been developed. Under such conditions, radiation-induced grafting polymerization of isobutylene, -methylstyrene, vinyl-n-butyl ether, styrene, acrylonitrile, and 4-vinylpyridine by the ionic mechanism at room temperature has been performed. The grafted copolymers of polyethylene, Teflon and polyvinyl chloride with monomers polymerized only ionically (isobutylene, -methylstyrene, vinyl-n-butyl ether) have been obtained for the first time. The kinetics of the radiation-induced grafting of vinyl-n-butyl ether on to polyethylene have been studied; the ionic mechanism has been confirmed. It has been found that the rates of the radiation-induced ionic grafting of styrene, acrylonitrile, and 4-vinylpyridine are much greater than those for radical grafting. The highest grafting rates are observed for 4-vinylpyridine. The mechanism of radiation-induced ionic grafting polymerization has been discussed; generalized kinetic equations have been derived to account for the contributions from radical and ionic processes.     

Synthesis and Properties of IPN Hydrogels Based on Konjac Glucomannan and Poly（acrylic acid）

As a random copolymer of β-(1,4) linked D-mannose and D-glucose, konjac gluco- mannan (KGM) is a naturally occurring water-soluble polysaccharide, and has been paid attention in the field of drug controlled release carriers potentially used in colon1,2. …     

Synthesis of the hydrophobic–hydrophilic macroporous poly divinylbenzene/poly(sodium acrylate) IPN resin and adsorption performance for berberine

The macroporous polydivinylbenzene/poly(methyl acrylate) interpenetrating polymer network (PDVB/PMA IPN) was prepared by the sequential suspension polymerization method, and was modified to be hydrophobic–hydrophilic macroporous polydivinylbenzene/poly (sodium acrylate) IPN (PDVB/PNaA IPN) by converting the PMA to PNaA under the condition of base. The effects of different mass ratio of the two networks and different cross‐linking degree of the second network on the pore structure and adsorption capacity of PDVB/PNaA IPN resin were studied. The PDVB/PNaA IPN resin whose adsorption quantity is the biggest was chosen to study further. The pore structure, the weak acid exchange capacity, the water retention capacity, and the swelling ability of PDVB/PNaA IPN resin were measured. The study focused on the adsorption isotherms of berberine at different temperatures. Isosteric adsorption enthalpy, adsorption Gibbs free energies can be calculated according to thermodynamic functions. The results show that the saturated adsorption quantity of berberine is up to 109.4 mg ml^?1 (wet resin) by the way of dynamic adsorption and desorption experiment. The resin could be reused by the mixture with 0.5% sodium chloride and 80% ethanol. On the one hand the hydrophobic PDVB in the PDVB/PNaA IPN resin has the ability of adsorption using π–π interaction, and on the other hand the hydrophilic PNaA in the PDVB/PNaA IPN resin has the ability of adsorption using ion exchange interaction. An important conclusion can be drawn that the PDVB/PNaA IPN resin has a promising application prospect in extracting and separating quaternary ammonium type alkaloids such as berberine. Copyright © 2009 John Wiley & Sons, Ltd.     

Grafting of Vinyudene Chloride. Model Studies with Poly(Vinyl Alcohol) as Substrate

The modification of coatings resins by graft polymerization of vinylidene chloride should produce a coatings binder with improved barrier properties. For superior color stability, vinylidene chloride must be copolymer-ized with other monomers such as alkyl acrylates and methacrylates. Ceric ion initiation was used to graft vinylidene chloride free-radically onto a model alcohol-containing polymer, polyvinyl alcohol. The effects of various reaction parameters on vinylidene chloride grafting were studied. Graft copolymers were characterized using selective solvent extraction, FTIR, SEM, XES, DSC, and x-ray diffraction.     

聚氨酯/聚苯乙烯互穿聚合物网络的研究

互穿聚合物网络形态和力学性能的研究已有报道^[1～3],但有关合成过程中分子量变化形态和性能的影响研究甚少。本文在动力学研究的基础上^[4],用GPC、DSC和Instron万能机研究了聚氨酯/聚苯乙烯互穿聚合物网络(PU/PSt-IPN)的分子量,玻璃化转变温度和力能,考察了分子量与相分离点之间的关系。     

POLYIMIDE/INORGANIC INTERPENETRATING POLYMER NETWORKS FOR STABLE SECOND-ORDER NONLINEAR OPTICS

Thermally stable NLO interpenetrating polymer networks (IPNs) based on an organosoluble polyimides functionalized with methacryloyl groups (PIB), and an alkoxysilane dye (ASD) have been developed. IPNs were formed through the free radical polymerization of methacryloyl group containing PIB, and sol-gel process of ASD. Optically clear samples exhibit large second-order optical nonlinearity (d₃₃ = 6.9-39.6 pm/V at 1064 nm) after poling and curing at 180°C for 2 hours. The temporal stability of the PIB/ASD IPN samples was much better than the inter-chain crosslinking polyimide/inorganic samples. The high rigidity of the polymer backbone and the interpenetrating structure of the polymer networks prevent the randomization of the aligned NLO chromophores     

Polymer hydrogel confined palladium nanoparticles as recyclable catalysts for Suzuki and Heck cross-coupling reactions

Reusable palladium nanoparticles highly dispersed in porous and hydrophilic interpenetrating polymer networks(IPN),i.e.,Pd@IPN hybrid gels,are employed for catalysis of Suzuki and Heck coupling reactions.Good yields are obtained with high turnover frequencies when the reactions are run with very low Pdloadings.The use of IPN gives better recyclability than that of crosslinked polyvinyl alcohol alone.The polymer networks allow the reactants to have easy access to the Pd metals.The catalysts combine high activity with the reusability offered by the heterogeneous system,without the need for strong coordination or chelating ligands.     

疏水/亲水大孔聚二乙烯基苯/聚(N-2-氨基乙基丙烯酰胺)IPN树脂的合成及对水杨酸吸附性能研究

采用分步悬浮聚合法制备了聚二乙烯基苯/聚丙烯酸甲酯(PDVB/PMA)大孔互穿聚合物网络,将其中的聚丙烯酸甲酯用乙二胺氨解,合成了具有疏水/亲水性能的聚二乙烯基苯/聚(N-2-氨基乙基丙烯酰胺)(PDVB/PNAEAM)大孔互穿聚合物网络(IPN);测定了该树脂的孔结构、含水量、弱碱交换量和溶胀性能;测定了该树脂对水杨酸在不同温度下的吸附等温线,利用热力学函数关系计算出了吸附焓、自由能和熵.推测PDVB/PNAEAM IPN树脂中疏水性的PDVB一网具有疏水作用吸附能力、亲水性的PNAEAM一网具有氢键作用吸附能力.动态吸附及脱附实验表明湿态PDVB/PNAEAM IPN树脂对水溶液中水杨酸的饱和吸附量达到46.1mg/mL.树脂可以通过4%NaOH溶液再生.PDVB/PNAEAM IPN树脂在分离工业废水中水杨酸等芳香有机酸有良好的应用前景.     

Merrifield-like resin beads by acid catalyzed incorporation of benzyl chloride into dehydrochlorinated PVC

A method is presented for preparing Merrifield-like resin beads starting from poly (vinyl chloride) (PVC) in spherical bead form. In this method, first, PVC is partially dehydrochlorinated in boiling methanolic KOH (20%) solution to create minute amounts of allylic carbon centers. Those centers trigger the un-zipping process and make further dehydrochlorination possible at relatively low temperatures (180-200 °C), while retaining the bead shapes. Acid catalyzed reaction of the dehydrochlorinated PVC particles with benzyl chloride at 180 °C yields crosslinked spherical bead polymers possessing chloromethyl benzene functions as high as 3.4 mmol g⁻¹. Experiments showed that, high yields of benzyl chloride insertions can be attained by using PVC samples with 40-50% of unsaturations. In the study transformation yields in each step were followed by conventional analytical methods and IR spectrometry. It was also demonstrated that modification of the chloromethyl groups either with KCN or sodium acetate proceeds with nearly quantitative yields, as in the case for chloromethylated styrene-divinyl benzene resins.     

Synthesis and characterization of κ‐carrageenan/poly(N,N‐diethylacrylamide) semi‐interpenetrating polymer network hydrogels with rapid response to temperature

In this study, a novel classical thermo‐ and salt‐sensitive semi‐interpenetrating polymer network (semi‐IPN) hydrogel composed of poly(N,N‐diethylacrylamide) (PDEAm) and κ‐carrageenan (KC) was synthesized by free radical polymerization. The structure of the hydrogels was studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). FTIR and SEM revealed that the semi‐IPN hydrogels possessed the structure of H‐bonds and larger number of pores in the network. Compared to the PDEAm hydrogel, the prepared semi‐IPN hydrogels exhibited a much faster response rate to temperature changes and had larger equilibrium swelling ratios at temperatures below the lower critical solution temperature (LCST). The salt‐sensitive behavior of the semi‐IPN hydrogels was dependent on the content of KC. In addition, during the reswelling process, semi‐IPN hydrogels showed a non‐sigmoidal swelling pattern. Copyright © 2008 John Wiley & Sons, Ltd.     

Suspension Polymerization of Vinyl Chloride with Programmed Temperature: Morphological Characteristics and Thermal Stability of Polyvinyl Chloride)

Polyvinyl chloride) obtained by intermittent polymerization in suspension with temperature programming, has been characterized from the point of view of morphological properties and of thermal stability. The data have been compared with the values of the morphological characteristics and thermal stability for the PVC samples obtained under identical polymerization conditions, but at constant temperature. The polyvinyl chloride) obtained by polymerization with temperature programming has the same properties as the polyvinyl chloride) obtained by simple polymerization at constant temperature, with an identical average molecular weight. However, the former polymer shows improved thermal stability, as well as a decrease in the volumetric properties.     

Improved oxygen permeability and mechanical strength of silicone hydrogels with interpenetrating network structure

<正>The interpenetrating polymer network(IPN) silicone hydrogels with improved oxygen permeability and mechanical strength were prepared by UV-initiated polymerization of monomers including methacryloxypropyl tris(trimethylsiloxy)silane(TRIS),2-hydroxyethylmethacrylate(HEMA) and N-vinyl pyrrolidone(NVP) in the presence of free radical photoinitiator and cationic photoinitiator.The polymerization mechanism was investigated by the formation of gel network.The structure of IPN hydrogels was characterized by Fourier transform infrared spectroscopy(FTIR), differential scanning calorimetry(DSC) and transmission electron microscopy(TEM).The results showed that the IPN hydrogels exhibited a heterogeneous morphology.The mechanical properties,surface wettability and oxygen permeability were examined by using a tensile tester,a contact angle goniometer and an oxygen transmission tester,respectively.The equilibrium water content of the hydrogels was measured by the gravimetric method.The results revealed that the IPN hydrogels possessed hydrophilic surface and high water content.They exhibited improved oxygen permeability and mechanical strength because of the incorporation of TRIS.     

Novel semi‐IPN through vinyl silane polymerization and crosslinking within PVC films

Novel semi‐IPN (interpenetrating polymer networks) were synthesized through vinyl silane modification of unplasticized poly(vinyl chloride) (PVC) films using relatively low temperatures, relatively high vinyl silane contents, and several different processing routes. A free‐radical initiator was used to promote reaction of the vinyl groups, and an aqueous acetic acid solution was used to promote the methoxysilane hydrolysis and condensation (HC) reactions for siloxane crosslink formation. A gel consisting of silane alone was formed prior to the HC process, indicating the formation of a semi‐IPN. The gel content following the HC process far exceeded the silane content, indicating a significant amount of PVC was entrapped by the silane network. This conclusion is supported by the homogeneous molecular structure and morphology of the films. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 8–22, 2001