Grafting of glycidyl methacrylate onto polypropylene using supercritical carbon dioxide

Free-radical grafting of glycidyl methacrylate (GMA) onto polypropylene (PP) films has been studied using supercritical carbon dioxide (SC-CO₂) as a solvent and a swelling agent. As the reaction temperature was below the melting point, PP was modified in the solid phase. The PP film was first soaked with the monomer GMA and benzoyl peroxide (BPO) as an initiator using SC-CO₂ at different experimental conditions of pressure, temperature, and thermal treatment time. After releasing CO₂, film GMA molecules were grafted onto PP in different times. Using this method, the degree of grafting and the morphology could be controlled through the combination of pressure, temperature, and soaking time. FTIR spectra confirmed that GMA had been grafted onto PP and that polypropylene-graft-glycidyl methacrylate (PP-g-GMA) presented a high surface reactivity for conductive polyaniline anchoring. DSC measurements and TG analyses showed that the thermal profiles of the graft copolymer and virgin PP are quite similar and that the graft PP does not exhibit changes in terms of thermal degradation profile and melting temperature, respectively. X-ray data showed that a high degree of grafting leads to a lower degree of crystallinity of polypropylene.     

Specific features of amination of poly(glycidyl methacrylate) chains grafted onto polypropylene fibers

Amination with diethylenetriamine of poly(glycidyl methacrylate) chains grafted onto polypropylene fibers by the radiation-chemical procedure was studied.     

Grafting of poly(acrylic acid) onto nonporous glass bead surfaces

The surface of glass beads were modified with covalently bonded poly(acrylic acid). The optimum reaction conditions were determined to graft poly(acrylic acid) effectively onto the glass surface. The dependence of the graft polymer molecular weight, grafting percentage and monomer weight conversion based on these reaction conditions were consistent with free radical kinetics. Grafting efficiency for azobisisobutyronitrile was more complex compared with the benzyl peroxide initiator system © 1997 John Wiley & Sons, Ltd.     

Synthesis and curing of poly(glycidyl methacrylate) nanoparticles

Glycidyl‐functional polymer nanoparticles [poly(glycidyl methacrylate) (PGMA)] were fabricated with microemulsion polymerization. The successful fabrication of PGMA nanoparticles was confirmed by Fourier transform infrared spectroscopy and transmission electron microscopy (TEM). A TEM image showed that the average diameter of the PGMA nanoparticles was approximately 10–28 nm and was fairly monodisperse. As the surfactant concentration increased, the average size of the nanoparticles decreased and approached an asymptotic value. A significant reduction of the nanoparticle size to the nanometer scale led to an enhanced number of surface functionalities, which played an important role in the curing reaction. The PGMA nanoparticles were cured with a low‐temperature curing agent, diethylene triamine, to produce ultrafine thermoset nanoparticles. The low‐temperature curing process was performed below the glass‐transition temperature of PGMA to prevent the coagulation and deformation of the nanoparticles. A TEM image indicated that the cured PGMA nanoparticles did not exhibit interparticle aggregation and morphological transformation during curing. The average size of the cured PGMA nanoparticles was consistent with that of the pristine PGMA nanoparticles © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2258–2265, 2005     

Electrorheological properties of hydrolyzed poly(glycidyl methacrylate) suspensions

 Electrorheological behavior of silicone oil suspensions of macroporous poly[(glycidyl methacrylate)-co-(ethylene dimethacrylate)]) (0.60 : 0.40 w) hydrolyzed to various degrees was investigated. Polarizability of particles expressed by the particle dipole coefficient and, consequently, pseudoplasticity of the system at low shear rates after application of an external electric field steeply increased with the hydrolysis degree of the copolymer. As the size and shape of particles remain unchanged during hydrolysis, a series of model suspensions with the same hydrodynamic properties (Newtonian or slightly pseudoplastic when no electric field was applied) but with different intensity of the electrorheological effect could be prepared. Under these conditions, the use of Mason number failed to correlate the apparent viscosity of suspensions of particles with different polarizability in the electric field. On the other hand, when polarizability of particles of a suspension system changes due to a higher temperature, a single curve in the plot of apparent viscosity vs. the Mason number could be obtained. Received: 17 February 1998 Accepted: 8 May 1998     

Blends of glycidyl methacrylate/methyl methacrylate copolymers with poly(vinylidene fluoride)

Blends of glycidyl methacrylate (GMA)/methyl methacrylate (MMA) copolymers with poly (vinylidene fluoride) (PVDF) were found to be miscible when the GMA content of the copolymer is 35.7 wt % or less. The miscible blends did not phase separate upon heating prior to thermal decomposition. The melting point depression method, based on both the Flory-Huggins theory and the equation of state theory of Sanchez-Lacombe, was used to evaluate interaction parameters for each pair. The magnitude of these parameters appears to be much larger than interaction energies evaluated by other methods. Possible reasons for this are discussed. © 1995 John Wiley & Sons, Inc.     

Grafting of Polystyrene-b-Poly(2-hydroxyethyl methacrylate) onto Carbon Fiber

Carbon fiber (CF) was subjected to oxidation and acyl chlorination, resulting in CF functionalized with acyl chloride (CF-COCl). The block copolymer polystyrene-b-poly (2-hydroxyethyl methacrylate) (PSt-b-PHEMA) was synthesized by atom-transfer radical polymerization (ATRP). According to the reaction between hydroxyl groups of block copolymer and acyl chloride groups on CF, the block copolymer was successfully grafted onto the surface of CF. Fourier-transform infrared spectra (FTIR), Gel permeation chromatography (GPC) were used to determine the chemical structure and molecular weight of block copolymer; Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR), Scanning electron microscopy (SEM) and thermal gravimetric analyses (TGA) were used to determine the chemical property and structure of grafted CF.     

Reactive poly(glycidyl methacrylate) microspheres prepared by dispersion polymerization

Poly(glycidyl methacrylate) [poly(GMA)] microspheres of narrow size distribution were prepared in a simple one‐step procedure by dispersion radical polymerization. Depending on the solvent used, poly(GMA) particle size could be controlled in the range of 0.5–4 μm by changing the solubility parameter of the reaction mixture. In N,N′‐dimethylformamide (DMF)/methanol mixture, the particle size increased and the size distribution broadened with decreasing initial solubility parameter. While in the DMF/methanol solvent system, hydroxypropyl cellulose (HPC) or cellulose acetate butyrate (CAB) were taken as steric stabilizers of the dispersion polymerization, poly(vinylpyrrolidone) (PVP) was used in alcoholic media. Contrary to the DMF/methanol system, narrow particle size distributions were obtained with PVP‐stabilized polymerizations in ethanolic, methanolic, propan‐1‐olic or butan‐1‐olic medium. Both the particle size and polydispersity were reduced with increasing stabilizer concentration. If lower molecular‐weight PVP was used, larger microspheres were obtained. Poly(GMA) samples prepared in a neat alcoholic medium virtually quantitatively retained oxirane group content after the polymerization. Reactivity of the poly(GMA) microspheres was confirmed by their hydrolysis and aminolysis. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3855–3863, 2000     

Compatibility and phase structure of binary blends of poly(lactic acid) and glycidyl methacrylate grafted poly(ethylene octane)

This work study is the compatibility, phase structure, and component interaction of poly(lactic acid) (PLA) and glycidyl methacrylate grafted poly(ethylene octane) (GMA-g-POE denoted as mPOE) blend by Fourier transform infrared (FTIR) spectra, dynamic mechanical analysis (DMA), scanning electron microscopy (SEM), and wide-angle X-ray diffraction (WAXD), respectively. All the binary blend compositions exhibit two distinct glass transition temperatures corresponding to the mPOE-rich and PLA-rich phases, respectively. Moreover, these two peaks approach each other with increasing mPOE content, indicating partial compatibility between the PLA and mPOE. Chemical reactions between the end carboxyl groups of the PLA and epoxy groups of the mPOE are considered as the driving force of the enhanced compatibility. They lead to an increase in viscosity of the blends and a decrease in the structural symmetry of PLA. This result brings about a decrease in the spherulite growth rate and the degree of crystallinity. Glass transition temperature (T_g) depression of mPOE is attributed to the negative pressure imposed on the dispersed rubber phase, resulting from differential contraction due to the thermal shrinkage mismatch upon cooling from the melt state. The negative pressure in the dispersed particles, in turn, would cause a dilational effect for the matrix ligament between the particles, and therefore increases the ductility and toughness of PLA.     

Grafting of poly(ethylene oxide) on poly(methyl methacrylate) by transesterification

The grafting of the potassium alkoxide derivative of poly(ethylene oxide) on poly(methyl methacrylate) in homogeneous solution in toluene was studied. The alkoxide was prepared by reaction with potassium metal with methanolic potassium methoxide, or with potassium naphthalene. The last was the most suitable for the systematic investigation of the grafting process. Soluble graft polymers were formed, and essentially the initial poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) participated in the production of graft polymer. The composition of the graft polymers and the frequency of grafting of the side chains were determined by NMR. The solubility of the graft polymers in methanol and water increased with increasing PEO contents, while the melting ranges decreased. Fractionation of the crude graft polymers showed that the grafting reaction was random, and graft polymers containing one PEO side chain per about 10–170 MMA units were obtained.     

Versatility of alkyne-modified poly(glycidyl methacrylate) layers for click reactions

Functional soft interfaces are of interest for a variety of technologies. We describe three methods for preparing substrates with alkyne groups, which show versatility for "click" chemistry reactions. Two of the methods have the same root: formation of thin, covalently attached, reactive interfacial layers of poly(glycidyl methacrylate) (PGMA) via spin coating onto silicon wafers followed by reactive modification with either propargylamine or 5-hexynoic acid. The amine or the carboxylic acid moieties react with the epoxy groups of PGMA, creating interfacial polymer layers decorated with alkyne groups. The third method consists of using copolymers comprising glycidyl methacrylate and propargyl methacrylate (pGP). The pGP copolymers are spin coated and covalently attached on silicon wafers. For each method, we investigate the factors that control film thickness and content of alkyne groups using ellipsometry, and study the nanophase structure of the films using neutron reflectometry. Azide-terminated polymers of methacrylic acid and 2-vinyl-4,4-dimethylazlactone synthesized via reversible addition-fragmentation chain transfer polymerization were attached to the alkyne-modified substrates using "click" chemistry, and grafting densities in the range of 0.007-0.95 chains nm(-2) were attained. The maximum density of alkyne groups attained by functionalization of PGMA with propargylamine or 5-hexynoic acid was approximately 2 alkynes nm(-3). The alkyne content obtained by the three decorating approaches was sufficiently high that it was not the limiting factor for the click reaction of azide-capped polymers.     

Emulsion grafting of glycidyl methacrylate onto polyethylene fiber

Graft polymerization of glycidyl methacrylate (GMA) onto polyethylene fiber was carried out in emulsion solution obtained by dissolving GMA in water with sodium n-dodecyl sulfate (SDS) as a surfactant. GMA micelles diameter was 415 nm at 5% GMA with 4% SDS and increased up to 1840 nm at 10% GMA with 12% SDS. Degree of grafting (Dg) which was estimated by the weight gain after grafting increased with the increment of GMA concentration in the range 2 to 8% and slightly reduced at 10% GMA. The increment in SDS concentration from 4% to 16% at 5% GMA reduced Dg from 120% to 18%. In emulsion graft polymerization, Dg was affected by covered area by GMA/SDS micelles on the fiber.     

Diethylenetriamine-grafted poly(glycidyl methacrylate) adsorbent for effective copper ion adsorption

Amine-functionalized adsorbents have attracted increasing interest in recent years for heavy metal removal. In this study, diethylenetriamine (DETA) was successfully grafted (through a relatively simple solution reaction) onto poly(glycidyl methacrylate) (PGMA) microgranules to obtain an adsorbent (PGMA-DETA) with a very high content of amine groups and the PGMA-DETA adsorbent was examined for copper ion removal in a series of batch adsorption experiments. It was found that the PGMA-DETA adsorbent achieved excellent adsorption performance in copper ion removal and the adsorption was most effective at pH>3 in the pH range of 1-5 examined. X-ray photoelectron spectroscopy (XPS) revealed that there were different types of amine sites on the surfaces of the PGMA-DETA adsorbent but copper ion adsorption was mainly through forming surface complexes with the neutral amine groups on the adsorbent, resulting in better adsorption performance at a higher solution pH value. The adsorption isotherm data best obeyed the Langmuir-Freundlich model and the adsorption capacity reached 1.5 mmol/g in the case of pH 5 studied. The adsorption process was fast (with adsorption equilibrium time less than 1-4 h) and closely followed the pseudo-second-order kinetic model. Desorption of copper ions from the PGMA-DETA adsorbent was most effectively achieved in a 0.1 M dilute nitric acid solution, with 80% of the desorption being completed within the first 1 min. Consecutive adsorption-desorption experiments showed that the PGMA-DETA adsorbent can be reused almost without any loss in the adsorption capacity.     

Grafting of poly(methyl vinyl ketone) onto aluminum surface

Polymers were grafted on aluminum surfaces in order to modify the chemical and physical properties of the interface. The properly cleaned and activated surface of the aluminum substrate was first "silanized" either with 3-(trimethoxysilyl)propylamine or allyltrimethoxysilane. The grafting was carried out following two methods: (i) by the reaction of preformed poly(methyl vinyl ketone) with the aminosilane-modified surface; and (ii) by polymerization of methyl vinyl ketone with the vinylsilane-modified surface. The modified aluminum surfaces were characterized by X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The new surfaces were examined by contact-angle measurements, and determinations of the Lewis basicity.     

Grafting of optically active nucleic acid base derivatives onto poly(vinylamine) as polynucleotide analogs

Polynucleotide analogs consisting of poly(vinylamine) as the backbone and optically active thymine and adenine derivatives as the pendants were synthesized. The pendants were prepared by the addition reaction of the nucleic acid base to ethyl crotonate followed by hydrolysis. The pendants were resolved using brucine as the resolving agent and an acetone-water mixture as the fractional crystallization solvent. The active esters of the pendants also were prepared. Poly(vinylamine) was isolated from water employing a weak acid, N-hydroxysuccinimide (HOSu), to protect the amino group of the poly(vinylamine). Model reactions for grafting were examined. Grafting reactions were carried out by reacting the active esters with the PVAm.6HOSu complex at room temperature.     

New interpenetrating polymer networks based on uralkyd/poly(glycidyl methacrylate)

Semi- and full-interpenetrating polymer networks (IPNs) based on uralkyd resin (UA)/poly(glycidyl methacrylate) were synthesized in the laboratory by the sequential technique. Infrared spectra of the homopolymers and the IPNs were studied. A study of the mechanical properties viz. tensile strength and elongation percentage was carried out. The apparent densities of the homopolymers and their IPNs were determined and compared. Glass transition studies of the IPNs were conducted with the aid of differential scanning calorimetry (DSC). Phase morphology of the IPNs was observed using scanning electron microscopy (SEM). DSC results revealed a single glass transition temperature (T_g) for both the semi- as well as the full-IPNs suggesting good interpenetration in them. The SEM micrographs as well as the IR-spectra gave an indication that apart form the interpenetration phenomena, grafting reaction between the -NCO groups of UA and the epoxy group of glycidyl methacrylate might have occurred to some extent.     

Grafting copolymerization of polyethylene glycol methacrylate (PEGMA) onto preirradiated PP films

Polyethylene glycol methacrylate (PEGMA) with different polyethylene oxide units were grafted onto polypropylene (PP) films by a preirradiation grafting method. The effect of co-solvent system on the degree of grafting and water contact angle were determined, respectively. The grafted sample films were verified by Fourier Transform Infrared (FTIR) spectroscopy in the attenuated total reflectance mode (ATR). The biocompatibility and blood compatibility of the grafted PP films were evaluated by the determination of protein adsorption, platelet adsorption and thrombus.     

Hemoglobin binding from human blood hemolysate with poly(glycidyl methacrylate) beads

Metal-chelating affinity beads have attracted increasing interest in recent years for protein purification. In this study, iminodiacetic acid (IDA) was covalently attached to the poly(glycidyl methacrylate) [PGMA] beads (1.6 μm in diameter). Cu(2+) ions were chelated via IDA groups on PGMA beads for affinity binding of hemoglobin (Hb) from human blood hemolysate. The PGMA beads were characterized by scanning electron microscopy (SEM). The PGMA-Cu(2+) beads (628 μmol/g) were used in the Hb binding-elution studies. The effects of Hb concentration, pH and temperature on the binding efficiency of PGMA-Cu(2+) beads were performed in a batch system. Non-specific binding of Hb to PGMA beads in the absence of Cu(2+) ions was very low (0.39 mg/g). The maximum Hb binding was 130.3 mg/g. The equilibrium Hb binding increased with increasing temperature. The negative change in Gibbs free energy (ΔG°<0) indicated that the binding of Hb on the PGMA-Cu(2+) beads was a thermodynamically favorable process. The ΔS and ΔH values were 102.2 J/mol K and -2.02 kJ/mol, respectively. Significant amount of the bound Hb (up to 95.8%) was eluted in the elution medium containing 1.0 M NaCl in 1 h. The binding followed Langmuir isotherm model with monolayer binding capacity of 80.3-135.7 mg/g. Consecutive binding-elution experiments showed that the PGMA-Cu(2+) beads can be reused almost without any loss in the Hb binding capacity. To test the efficiency of Hb depletion from blood hemolysate, eluted portion was analyzed by fast protein liquid chromatography. The depletion efficiency for Hb was above 97.5%. This study determined that the PGMA-Cu(2+) beads had a superior binding capacity for Hb compared to the other carriers within this study.     

Antimicrobial activities of polymeric quaternary ammonium salts from poly(glycidyl methacrylate)s

Amino poly(glycerol methacrylate)s (PGOHMAs) were synthesized from linear and 8‐arm poly(glycidyl methacrylate)s (PGMAs) via ring opening reactions with methylethylamine (MEA), diethylamine, and dipropylamine, respectively, which were further modified by quaternization reaction using methyl iodide to obtain quaternized PGMAs (QPGMAs for short). The products were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, gel permeation chromatography, and thermogravimetric analysis. The amination percentage of amino PGOHMAs and the degree of quaternization of QPGMAs were calculated by elemental analysis and X‐ray photoelectron spectroscopy, respectively. According to the solubility test results, 8‐arm PGOHMA modified with MEA (S8‐MEA) is the only water‐soluble derivative of amino PGOHMAs and was employed as a positive control for the comparison with QPGMAs. Antimicrobial studies on these PGMA derivatives were carried out by testing the minimum inhibitory concentration and the bacteria inhibitive rate against Escherichia coli and Staphylococcus aureus. The results indicated that QPGMAs possessed higher antimicrobial activity than S8‐MEA and exhibited increased antimicrobial activity against both bacteria with an increased degree of quaternization in weak basic conditions. Moreover, the chemical structure of PGMA derivatives and pH value of the assay conditions were found to affect the antimicrobial activity. Copyright © 2013 John Wiley & Sons, Ltd.