Synthesis and characterization of some polyacrylate/montmorillonite nanocomposites by in situ emulsion polymerization using redox initiation system

Intercalated modification of Montmorillonite clay (MMT) with three different amino acids—Alanine, Leucine, and Phenylalanine—in the presence of hydrochloric acid followed by surface modification by methyl triethoxy silane coupling agent to produce double modified Montmorillonite clay which is characterized by X‐ray diffraction (XRD) and Thermogravimetric analysis (TGA). The data shows an increase in d‐spacing of modified clay as a result of cationic exchange. Double modified MMT clay was used in the preparation of Polyacrylate/clay nanocomposites by using an in situ redox emulsion polymerization of polyglycidylmethacrylate (PGMA) and polymethylmethacrylate (PMMA). The structure and properties of the prepared nanocomposites were achieved by XRD, TGA, and SEM. The results show that all weight loses temperatures for the nanocomposite samples are higher than that of pure polymer in both PGMA and PMMA. It is also obvious that the increasing in the clay content plays an effective role in the increasing of thermal stability of these materials. SEM shows that the clay is more homogenously dispersed in PMMA than in PGMA matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Preparation of amidoximated poly(glycidyl methacrylate) microbeads

Poly(glycidyl methacrylate) (PGMA) microbeads were synthesized by a simple suspension polymerization of glycidyl methacrylate and ethylene glycol dimethacrylate. The epoxy groups of the microbeads were firstly modified with 3,3′‐iminodipropionitrile (IDPN) and the resulting nitrile groups were then converted to amidoxime. From scanning electron microscopy studies, the average size of the PGMA microbeads was determined as 170 µm, which was not changed by the modification processes. For the modification of epoxy groups with IDPN, the intensity of the C≡N absorption band at 2249 cm^?1 increased proportionally with reaction time; for the conversion of nitrile groups to amidoxime, it decreased. Attenuated total reflectance Fourier transform infrared spectroscopy measurements clearly showed the disappearance of the original nitrile groups and the formation of amidoxime groups through treatment with hydroxylamine under the reaction conditions specified. The microbeads possessed good thermal and morphological properties and chemical stability suitable for practical use. Therefore, the amidoximated PGMA microbeads could be used in batch and continuous processes for the adsorption of uranyl ions from seawater or aqueous media. Copyright © 2010 Society of Chemical Industry     

A new type of poly(glycidyl methacrylate) microbeads with surface grafted iminodiacetic acid: Synthesis and characterization

In this study, firstly, uniform poly(glycidyl methacrylate) (PGMA) microbeads with an average diameter of 230 μm were synthesized by suspension polymerization of GMA monomer and ethylene glycol dimethacylate (EGDMA) crosslinker in the presence of benzoyl peroxide (BPO) initiator . Secondly, the PGMA microbeads obtained were modified with iminodiacetic acid (IDA) to afford a new type of microbeads carrying two pendant carboxylic acid groups on the surface. The IDA modification was followed by Attenuated Total Reflectance Fourier Transformed Infrared (ATR-FTIR) measurements. The surface morphology and thermal behavior of the PGMA and their modificated form were also characterized by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) techniques further confirming modification.     

Improved synthesis of a branched poly(ethylene imine)‐modified cellulose‐based adsorbent for removal and recovery of Cu(II) from aqueous solution

This study focuses on an improved synthesis of a branched poly (ethylene imine) (PEI)‐modified cellulose‐based adsorbent (Cell‐g‐PGMA‐PEI). We aim to improve the adsorbent capacity by reducing side reaction of epoxide ring opening during graft copolymerization of glycidyl methacrylate (GMA) onto cellulose which increases the content of epoxy groups, anchors to immobilize branched PEI moieties. FTIR spectra provided the evidence of successful graft copolymerization of GMA onto cellulose initiated by benzoyl peroxide (BPO) and modification with PEI. The amount of epoxy groups of Cell‐g‐PGMA was 4.35 mmol g^?1 by epoxy titration. Subsequently, the adsorption behavior of Cu(II) on cell‐g‐PGMA‐PEI in aqueous solution has been investigated. The data from the adsorption kinetic experiments agreed well with pseudo‐second‐order model. The adsorption isotherms can be interpreted by the Langmuir model with the maximum adsorption capacity of 102 mg g^?1 which was largely improved compared with the similar adsorbent reported. The dynamic adsorption capacity obtained from the column tests was 119 mg g^?1 and the adsorbent could be regenerated by HCl of 0.1 mol L^?1. Results indicate that the novel pathway for the synthesis of Cell‐g‐PGMA‐PEI exhibits significant potential to improve the performance of adsorbents in removal and recovery of Cu(II) from aqueous solution. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Preparation of normal‐phase HPLC stationary phase based on monodisperse hydrophilic polymeric beads and their application

The monodisperse, 5.0 μm hydrophilic macroporous poly(glycidymethacrylate‐co‐ethylenedimethacrylate) beads were first prepared based on monosized linear poly(glycidylmethacrylate) beads as seed by using a single‐step swelling and polymerization method. The seed beads prepared by dispersion polymerization exhibited good absorption of the monomer phase. The pore size distribution of the beads was evaluated by mercury instrusion method. The surface area was calculated from the BET isotherms of nitrogen adsorption and desorption. The beads were modified to be a normal‐phase liquid chromatographic (NPLC) stationary phase for high performance liquid chromatography (HPLC) in the following steps. First, the beads were completely hydrolyzed. Second, hydrolyzed particles were reacted with epichlorihydrin followed by another hydrolysis of the newly introduced epoxide groups. The retention properties of the NPLC stationary phase were easily modulated by changes in the composition of the mobile phase. The performance of theses beads was demonstrated with the separation of a variety of polar compounds. The satisfactory results were obtained. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Improvement of autohesive and adhesive properties of polyethylene plates by photografting with glycidyl methacrylate

Glycidyl methacrylate (GMA) was photografted with the low‐ and high‐density polyethylene (LDPE and HDPE) plates to provide their surfaces with autohesive and adhesive properties. The chemical composition and wettability of the GMA‐grafted LDPE and HDPE (LDPE‐g‐PGMA and HDPE‐g‐PGMA) plates remained constant above full coverage of the surfaces with grafted PGMA chains. Autohesive strength obtained with 1,4‐dioxane as a good solvent of PGMA increased with an increase in the grafted amount and substrate breaking was observed at the grafted amount of 117 μmol/cm². The grafted amount at substrate breaking was decreased by increasing the temperature and load during heat pressing. Adhesive strength was effectively enhanced by use of multi‐functional amine compounds because of the increase in the reaction between primary or secondary amine groups and epoxy groups appended to the grafted PGMA chains. In addition, the decrease in the amine compound concentration and the increase in the number of amino groups in the amine compounds used led to the decrease in the grafted amounts at substrate breaking. Substrate breaking occurred at lower grafted amounts for the HDPE‐g‐PGMA plates than for the LDPE‐g‐PGMA plates because the location of the photografting was restricted to the outer surface region for the HDPE plate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 493–500, 2007     

Effect of noncovalent chemical modification on the electrical conductivity and tensile properties of poly(methyl methacrylate)/carbon nanotube composites

Noncovalent chemical modification by initiated chemical vapor deposition technique is applied to carbon nanotubes (CNTs) to reduce average agglomerate size of the nanoparticles in the polymer matrix and to improve surface interaction between the composite constituents. CNT surfaces are coated conformally with thin poly(glycidyl methacrylate) (PGMA) polymer film and coated nanoparticles are incorporated in poly(methyl methacrylate) (PMMA) polymer matrix using solvent casting technique. Conformal PGMA coatings around individual nanotubes were identified by scanning electron microscopy analysis. Transmission electron microscopy and optical microscopy analyses show homogeneous composite morphology for composites prepared by using PGMA coated nanotubes. Fourier Transform Infrared and X‐ray photoelectron spectroscopy analyses show the successful deposition of polymer with high retention of epoxide functionality. PGMA coating of CNTs exhibits improvement in electrical conductivity and tensile properties of PGMA‐CNT/PMMA systems when compared with uncoated nanoparticles. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Role of reactive compatibilization in preparation of nanosilica/polypropylene composites

The effect of reactive compatibilization on the mechanical properties of nanosilica filled polypropylene (PP) composites was studied in this work. First, the nanoparticles were grafted with poly(glycidyl methacrylate) (PGMA) by solution free‐radical polymerization, and then melt blended together with PP matrix and aminated PP (PP‐g‐NH₂) that acts as reactive compatibilizer. The reaction between epoxide groups of the grafted PGMA on the nanoparticles and amine groups of PP‐g‐NH₂ during compounding greatly improved interfacial interaction in the composites. As a result, tensile strength, Young's modulus, and notch impact strength of PP composites were increased at rather low filler content. The experimental results indicated that the reinforcing and toughening effects were controlled by flexibility of the grafted polymer as well as processing methods. POLYM. ENG. SCI., 47:499–509, 2007. © 2007 Society of Plastics Engineers.     

聚甲基丙烯酸缩水甘油酯为主链的咪唑型螯合树脂的合成、表征及吸附性能研究

用分散聚合法合成了聚甲基丙烯酸缩水甘油酯(PGMA),然后引入咪唑功能基合成了螯合树脂(PGMA-Imi),用傅立叶变换红外光谱(FTIR)与扫描电镜(SEM)研究了其结构与粒子表面形态,元素分析测定功能基含量,并对Cu2+等离子进行了吸附研究。结果表明所得PGMA微球为微米级、单分散性很好,所得螯合树脂(PGMA-Imi)对Cu2+的吸附效果最好。     

Chemoenzymatic synthesis of the novel amphiphilic diblock copolymer poly[caprolactone‐block‐(glycidyl methacrylate)] from a bifunctional initiator and its micellization behavior

The chemoenzymatic synthesis of a novel diblock copolymer consisting of a hydrocarbon block of polycaprolactone (PCL) and an epoxy‐based block of poly(glycidyl methacrylate) (PGMA) was achieved by the combination of enzymatic ring‐opening polymerization (eROP) and atom transfer radical polymerization (ATRP). A trichloromethyl‐terminated PCL macrointiator was obtained via Novozyme 435‐catalyzed eROP of ε‐caprolactone from a bifunctional initiator, 2,2,2‐trichloroethanol, under anhydrous conditions. PCL‐b‐PGMA diblock copolymers were synthesized in a subsequent ATRP of glycidyl methacrylate. The kinetics analysis of ATRP indicated a ‘living’/controlled radical polymerization. The macromolecular structure and thermal properties of the PCL macroinitiator and of the diblock copolymer were characterized using NMR spectroscopy, gel permeation chromatography and differential scanning calorimetry. The well‐defined PCL‐b‐PGMA amphiphilic diblock copolymer self‐assembled in aqueous solution into nanoscale micelles. The size and shape of the resulting micelles were investigated using dynamic light scattering, transmission electron microscopy and tapping‐mode atomic force microscopy. Copyright © 2007 Society of Chemical Industry     

Polyethersulfone‐Modified Montmorillonite Hybrid Beads for the Removal of Bisphenol A

Abstract

Na‐Montmorillonite (Na‐MMT) was modified by cetyltrimethylammonium bromide first, then polyethersulfone (PES)‐MMT hybrid beads were prepared using a liquid‐liquid phase separation technique for the removal of bisphenol (BPA). The interlayer spacing of the MMT increased after the modification. Adsorption data showed that the modified MMT had excellent adsorption ability to BPA due to the hydrophobic interaction and large porosity. An adsorption dynamics model for the beads was constructed using concentration decrease data. Also, the experimental data of BPA adsorption were adequately fitted with both Langmuir and Freundlich equations. These results indicated that the PES‐MMT hybrid particles have the potential to be used in the environmental application.     

Adsorption and desorption properties of grafted polyethylene films modified with polyethylenimine chains

The chelating membranes for adsorption of metal ions were prepared by the bonding of linear and branched polyethylenimines (LPEI and BPEI) on the glycidyl methacrylate (GMA) photografted porous polyethylene (pPE) (pPE‐g‐PGMA) films. The adsorption and desorption properties of LPEI and BPEI‐bonded pPE‐g‐PGMA (LPEI‐(pPE‐g‐PGMA) and (BPEI‐(pPE‐g‐PGMA)) films to Cu²⁺ ions were investigated as a function of the grafted amount, amount of bonded PEI, molecular mass of PEI, pH value, and temperature. The amounts of LPEI and BPEI bonded to the pPE‐g‐PGMA films increased over the reaction time, and the bonding of LPEI and BPEI offered the water‐absorptivity to the pPE‐g‐PGMA films. The amount of adsorbed Cu²⁺ ions at pH 5.0 had the maximum value at the grafted amount of 10 mmol/g for the (LDPEI‐(pPE‐g‐PGMA) and (BPEI‐(pPE‐g‐PGMA) films with a constant amount of bonded PEI. The amount of adsorbed Cu²⁺ ions for the LPEI‐(pPE‐g‐PGMA) films was higher than that for the BPEI‐(pPE‐g‐PGMA) films. The amount of Cu²⁺ ions desorbed from the LPEI‐(pPE‐g‐PGMA) and BPEI‐(pPE‐g‐PGMA) films increased with an increase in the HCl concentration. The quantities of Cu²⁺ ions of about 100% were desorbed in the aqueous HCl solutions of more than 0.1M for the LPEI‐(pPE‐g‐PGMA) films and more than 0.05M for the BPEI‐(pPE‐g‐PGMA) films. The amounts of adsorbed Cu²⁺ ions were almost the same in each adsorption process at pH 5.0. This indicates that the LPEI‐(pPE‐g‐PGMA) and BPEI‐(pPE‐g‐PGMA) films can be applied to a repeatedly generative chelating membrane for adsorption and desorption of metal ions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5965–5976, 2006     

Pseudospecific magnetic affinity beads for immunoglobulin‐G depletion from human serum

Magnetic poly(ethylene glycol dimethacrylate‐N‐methacryloyl‐(L )‐histidine methyl ester) [m‐poly(EGDMA‐MAH)] beads were prepared by suspension polymerization for the affinity depletion of immunoglobulin‐G (IgG) from human serum in a batch system. Elemental analysis of the magnetic beads for nitrogen was estimated as 70 μmol MAH/g polymer. IgG adsorption onto the m‐poly(EGDMA) was negligible. Higher adsorption value (up to 46.8 mg/g) was obtained in which the m‐poly(EGDMA‐MAH) beads were used. IgG adsorption capacity of the magnetic beads increased with an increase in the concentration of IgG. The maximum IgG adsorption was observed at pH 6.5 for MOPS buffer. IgG molecules could be repeatedly adsorbed and eluted with these adsorbents, without noticeable loss in their IgG adsorption capacity. Adsorption capacity decreased for both increasing salt concentration and temperature. In this study, we show that m‐poly(EGDMA‐MAH) beads (wherein IgG molecules bind directly with the matrix) can be used directly for affinity depletion without further modification. Higher adsorption value was obtained from human serum (up to 85.7 mg/g). The elution results demonstrated that the adsorption of IgG to the adsorbent was reversible. The depletion efficiencies for IgG were above 85% for all studied concentrations. Eluted portion was analyzed for testing the IgG removal efficiency by two dimensional gel electrophoresis. Eluted proteins include mainly IgG, and a small number of nonalbumin proteins such as apolipoprotein A1, serotransferrin, haptoglobulin, and α1‐antitrypsin. IgA was not identified in eluted fraction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Preparation and characterization of polystyrene/modified carbon black composite beads via in situ suspension polymerization

A facile and effective method was introduced into this article to modify carbon black (CB). Fourier‐transform infrared spectrum demonstrates the chemical structure of CB has obviously changed after surface modification. Compared with pure CB, the thermogravimetric analysis illustrates thermal behavior of modified CB (MCB) exhibits a well‐defined difference from CB. Besides, aggregation phenomenon existed in CB is weakened evidently after surface modification. A series of polystyrene (PS) composite beads in presence of MCB were synthesized via in situ suspension polymerization process. The effects of benzoyl peroxide dosage and MCB dosage on the polymerization time of PS composite beads were systematically researched. After modification, the inhibition effect of MCB on the polymerization of PS/MCB composite beads is obviously weakened. The dispersion of MCB in PS/MCB composite beads is greatly improved than that of CB in PS/CB composite beads. Moreover, PS/MCB beads have the better thermal stability than that of PS and PS/CB composite beads. POLYM. COMPOS., 34:1110–1118, 2013. © 2013 Society of Plastics Engineers     

Adsorption and desorption properties of the chelating membranes prepared from the PE films

The chelating membranes for adsorption of metal ions were prepared by the photografting of glycidyl methacrylate (GMA) onto a polyethylene (PE) film and the subsequent modification of the resultant GMA‐grafted PE (PE‐g‐PGMA) films with disodium iminodiacetate in an aqueous solution of 55% DMSO at 80°C. The adsorption and desorption properties of the iminodiacetate (IDA) group‐appended PE‐g‐PGMA (IDA‐(PE‐g‐PGMA)) films to Cu²⁺ ions were investigated as functions of the grafted amount, pH value, Cu²⁺ ion concentration, and temperature. The amount of adsorbed Cu²⁺ ions increased with an increase in the pH value in the range of 1.0–5.0. The time required to reach the equilibrium adsorption decreased with an increase in the temperature, although the degree of adsorption stayed almost constant. The amount of Cu²⁺ ions desorbed from the (IDA‐(PE‐g‐PGMA)) films increased and the time required to reach the equilibrium desorption decreased with an increase in the HCl concentration. About 100% of Cu²⁺ ions were desorbed in the aqueous HCl solutions of more than 0.5M. The amounts of adsorbed and desorbed Cu²⁺ ions were almost the same in each cyclic process of adsorption in a CuCl₂ buffer at pH 5.0 and desorption in an aqueous 1.0M HCl solution. These results indicate that the IDA‐(PE‐g‐PGMA) films can be applied to a repeatedly generative chelating membrane for adsorption and desorption of metal ions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99:1895–1902, 2006     

Sulfonation of (glycidyl methacrylate) chains grafted onto nonwoven polypropylene fabric

Sulfonation of polyglycidyl methacrylate (PGMA) chains grafted onto nonwoven polypropylene fabric is investigated in detail. Sulfonation reaction consists in implantation of sulfonate groups via epoxy ring‐opening of PGMA chains grafted onto nonwoven polypropylene fabric by reaction between the GMA‐grafted sample and sodium hydrogensulfite in water–dimethylformamide solution. On the basis of analyses of IR spectra of the appropriate samples and data of backward titration, two simultaneous processes are demonstrated to take place during the sulfonation reaction. These processes are the implantation of sulfonate groups via opening of the GMA epoxy rings and hydrolysis of the GMA epoxy rings with α‐glycol groups formation. The main peculiarities of the sulfonation reaction in depending on the GMA grafting degree are reported. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

Preparation of grafted polytetrafluoroethylene fibers and adsorption of bilirubin

BACKGROUND: A successful hemoperfusion technique requires that the adsorbent for bilirubin should have a high specificity, adsorption capacity and adsorption rate, blood compatibility and no toxicity. Compared with polymer microbeads, polytetrafluoroethylene (PTFE) fibers have many advantages. The aim of the work reported here was to prepare a new polytetrafluoroethylene‐graft‐poly(glycidyl methacrylate)‐block‐polyethyleneimine (PTFE‐g‐PGMA‐b‐PEI) adsorbent for bilirubin based on PTFE fibers by the ⁶⁰Co radiation‐induced graft polymerization of GMA followed by the chemical modification of the epoxy groups on the PTFE‐g‐PGMA fibers with PEI. In addition, the adsorption properties of this novel adsorbent for bilirubin were examined. RESULTS: The highest content of amino groups obtained on the PTFE‐g‐PGMA‐b‐PEI fibers was 1.87 mmol g^?1. The maximum adsorption capacity of the grafted fibers was 9.6 mg g^?1 at pH = 6.5. Bilirubin adsorption on these fibers obeyed the Langmuir model. Also, these fibers possessed the ability to selectively adsorb bilirubin in the presence of bovine serum albumin. CONCLUSION: The PTFE‐g‐PGMA‐b‐PEI fibers have a high adsorption capacity for bilirubin and excellent adsorption properties. In addition, this new adsorbent is inexpensive, easy to prepare and has no toxicity. So the PTFE‐g‐PGMA‐b‐PEI fibers as a biomedical adsorbent are promising for the removal of bilirubin through the hemoperfusion technique. Copyright © 2009 Society of Chemical Industry     

Tribological behavior of epoxy composites containing reactive SiC nanoparticles

The present article evaluated the sliding wear behaviors of epoxy and its composites filled with SiC nanoparticles. Polyglycidyl methacrylate (PGMA) and a copolymer of glycidyl methacrylate and styrene were grafted onto the nanoparticles as a measure of surface pretreatment, respectively. The grafted polymers were selected because the epoxide groups on PGMA would take part in the curing reaction of epoxy resin and covalently connect the nanoparticles with the matrix, while styrene acted as a copolymerized monomer to adjust the amount of the reactive groups of the grafted macromolecular chains, and hence the compatibility between the grafted polymers and the matrix. In comparison to the composites filled with untreated nano‐SiC particles, the composites with the grafted nano‐SiC exhibit improved sliding wear resistance and reduced frictional coefficient owing to the chemical bonding at the filler/matrix interface. The results were analyzed in terms of structure‐properties relationship of the composites. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 2608–2619, 2007     

聚合物/SiO2核壳结构单分散微球的制备

聚合物/SiO2核壳结构单分散微球比聚合物微球具有更好的稳定性,有望在较高的温度和有机溶剂中得到使用.为了制备出这种微球,作为模板的聚合物微球首先进行表面胺化处理,然后正硅酸乙酯被诱导在其表层水解缩合从而形成SiO2壳层;采用扫描电子显微镜(SEM)、傅里叶红外光谱仪(FTIR)、激光粒度仪,烧蚀质量损失等手段分析表征...     

Preparation and use of magnetic poly(glycidyl methacrylate) resin in drinking water treatment

Magnetic poly(glycidyl methacrylate) (m‐PGMA) was synthesized and characterized, and its efficiency in removing natural organic matter (NOM) and carbamazepine (CBZ) from synthetic water was studied. The effects of factors such as time and m‐PGMA dosage on NOM removal were investigated. Furthermore, magnetic ion exchange resin (MIEX®) was used for comparison with m‐PGMA in CBZ removal. m‐PGMA was found to have a strong magnetic character whose specific saturation magnetization and mass fraction of magnetite were 10.79 emu g^?1 and 6.166 wt %, respectively, thus providing additional utility for m‐PGMA in slurry form in completely mixed continuous‐flow reactors. Lab‐scale studies showed that the removal rate rose rapidly with time and reached a pseudo‐equilibrium after 30 min. In addition, the highest doses of m‐PGMA achieved the highest removal efficiency. After 30 min of contact with 5, 10, and 15 mL L^?1 of m‐PGMA, the removal rates, based on UV absorbance measurements at 254 nm (UV₂₅₄), were 56%, 67%, and 79%, respectively, whereas the removal rates of dissolved organic carbon (DOC) were 53%, 60%, and 72%, respectively. Additionally, the scale ultraviolet absorbance values (SUVA) decreased during a 30 min contact time, thereby suggesting that the NOM removed by m‐PGMA had greater aromatic character. In multiple‐loading tests, UV₂₅₄ removal gradually decreased and achieved 18.39% at 1600 bed volume; it was kept constant at this level. Compared to MIEX®, m‐PGMA had a higher CBZ removal rate (27.8% and 34.7% for 20 mL L^?1 and 25 mL L^?1 of m‐PGMA, corresponding to the removal of 200 μg L^?1 CBZ). The resulting higher removal rate of CBZ contributed to stronger adsorption, a higher specific surface area, and larger pore volume. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013