Polymerization Of Glycidyl Methacrylate Research Articles

New polymeric composites for heat transfer

The aim of this study was the obtaining of a modified textile material capable of absorbing the body heat resulting from intense activities and maintaining the optimum human body temperature (36–37 °C). Thus, temperature-sensitive reactive polymer particles were obtained through the use of suspension polymerization of glycidyl methacrylate and paraffin and subsequent grafting on textile material was realized. The materials were characterized in order to determine their morphological, thermal, and comfort parameters.

Wall-Coated Polymer Brushes as Support for Chiral Organocatalysts in Microreactors

Cinchona alkaloid and proline derivatives as enantioselective catalysts were covalently attached onto the inner walls of a microreactor using glycidyl methacrylate polymer brushes. The successful formation of the organocatalyst-functionalized brush layers on flat silicon oxide surfaces was confirmed by several techniques such as Fourier transform infrared (FT-IR), ellipsometry, and X-ray photoelectron spectroscopy (XPS). The applicability of the cinchona alkaloid (cinchonidine or quinidine)- and proline-containing polymer brushes in a microreactor was demonstrated for the Diels–Alder reaction between anthrone and N-substituted maleimides, and the aldol reaction between 4-nitrobenzaldehyde and cyclohexanone, respectively, which showed moderate conversions (up to 55% and 23%, respectively) and moderate to good enantioselectivities (up to 55% and 93%, respectively). The pristine catalytic activity of the microreactor was intact even after 1 month.

Preparation and Characterization of Magnetic Microspheres with an Epoxy Group Coating and Their Applications for Lipase Immobilization

Magnetic microspheres coated with epoxy groups (Ep) were prepared by suspension polymerization of glycidyl methacrylate (GMA) and styrene (St) in the presence of oleic acid-coated Fe3O4 (OA-Fe3O4) nanoparticles, using ethylene glycol dimethacrylate (EGDMA) as a cross-link reagent. The resulting magnetic microspheres were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometry (VSM). It was verified that the magnetic microspheres had small diameters of 10–30 μm, as well as having super paramagnetism with a saturation magnetization of 10.5 emu/g. Porcine pancreas lipase (PPL) was selected as a model enzyme to be covalently immobilized (IPPL) on the magnetic microspheres via the reactive Ep; they had an activity yield up to 58.6%, when the protein loading reached 55.4 mg/g supports. In addition, the resulting immobilized lipases exhibited a better thermal stability, temperature and pH endurance than that of the free ones. In particular, an excellent reusability of IPPL, which could meet industrial requirements, was achieved.

Piperazine-Containing Polymer Brush Layer as Supported Base Catalyst in a Glass Microreactor

The covalent attachment of piperazine onto the inner walls of a microreactor using glycidyl methacrylate polymer brushes has been demonstrated. The piperazine-containing polymer brushes were first grown on a flat silicon oxide surface and were characterized by contact angle, Fourier transform infrared (FT-IR), ellipsometry, and X-ray photoelectron spectroscopy (XPS). The applicability of the catalytic polymer brushes in a microreactor was demonstrated for the Knoevenagel and nitroaldol condensation reactions, and the synthesis of coumarin derivatives. The catalytic activity of the microreactor was still intact even after 2 months.

磺丁基醚- β -环糊精修饰毛细管电色谱拆分地平类药物对映体

采用甲基丙烯酸缩水甘油酯原位聚合物基质，将磺丁基醚- β -环糊精修饰到毛细管内壁，制得了一种毛细管电色谱手性柱（SECDP），并通过红外光谱（IR）和扫描电子显微镜（SEM）表征了其结构. 磺酸基可提供足够稳定的正向电渗流（EOF），基于磺丁基醚- β -环糊精在固定相和流动相中的协同作用，通过优化手性添加剂浓度、pH值、施加电压、温度及有机调节剂含量等条件，利用该开管电色谱柱拆分了氨氯地平、尼莫地平和尼卡地平等10种地平类手性药物对映体. 优化的流动相组成为20 mmol/L NaH 2 PO 4 （pH=4.0），含4.0 mmol/L 磺丁基醚- β -环糊精，乙腈的体积分数为10%~25%，施加电压15~25 kV，温度为15 ℃，电动进样2 kV×5 s，检测波长为236 nm. 在上述条件下，分离度（ R S ）可达3.62，柱效达61011块/m，分析时间一般为6~15 min. 基于色谱分离数据，探讨了相关的手性分离机理.

Wear of nanofilled dental composites at varying filler concentrations.

The aim of this study is to examine the effects of nanofiller concentration on the mechanisms of wear of a dental composite. Nanofilled composites were fabricated with a bisphenol A glycidyl methacrylate polymer and 40 nm SiO2 filler particles at three filler loads (25, 50, and 65 wt %). The elastic modulus, flexural strength, and hardness of the composites and the unfilled resin were measured. The materials (n = 8) were tested in the modified wear testing device at 50,000, 100,000, and 200,000 cycles with 20N force at 1 Hz. A 33% glycerine lubricant and stainless steel antagonist were used. The worn composite and antagonist surfaces were analyzed with noncontact profilometry and SEM. The volumetric wear data indicated that there are significant differences between filler concentrations and cycles (p < 0.05). A trend was noted that increasing filler content beyond 25% decreased the wear resistance of the composites. Increasing filler content increased hardness and modulus and increased flexural strength up to 50% fill. SEM evaluation of the worn specimens indicated that the resin and 25% filled materials exhibited cracking and failed by fatigue and the 50 and 65% filled materials exhibited microcutting and failed by abrasive wear. Based on the results of this study, composite manufacturers are recommended to use a filler concentration between 25 and 50% when using nanosized filler particles.

Modification of copolymers using nucleophilic reactions between glycidyl methacrylate and 9-anthracene carboxylic acid

Epoxide ring opening reaction is a route that explains the chemical modification of glycidyl methacrylate (GMA) polymers with nucleophilic reagent containing hydroxyl, carboxyl or amine groups. In this work copolymers of GMA have been modified by incorporation of bulky 9-anthracene carboxylic acid groups. The glycidyl methacrylate polymers were prepared by radical copolymerization of GMA methyl, methacrylate, ethyl methacrylate, methyl acrylate and butyl acrylate mixtures. The polymers were modified through epoxy functional groups in two steps: (i) the glycidyl methacrylate copolymers were dissolved in N,N-di-methyl formamide; (ii) 9-anthracene carboxylate salt was added to the copolymers solutions prepared in step (i). The structure of all the resulting polymers was characterized and confirmed by FT-IR and 1H-NMR spectroscopic techniques. The presence of bulky 9-anthracene carboxylate groups in polymer side chain leads to different applications in the polymer industry and also a series of novel modified polymers are obtained.

Preparation of grafted particles PGMA/SiO2 with a new surface-initiating system of mercapto group/BPO and their functionalization transformation

A new surface-initiating system for free radical graft-polymerization of lipophilic vinyl monomer was designed. The coupling agent γ-mercaptopropyl trimethoxysilane (MPMS) was first bonded onto the surfaces of silica gel particles, obtaining the modified particles MPMS-SiO2. So a new surface-initiating system was constituted by mercapto group on the surfaces of MPMS-SiO2 and dibenzoyl peroxide (BPO) in the solution. Through the proton transfer of mercapto groups to the decomposition product of BPO, a great deal of primary sulfur free radicals were produced on the surfaces of the particles, leading to the graft-polymerization of glycidyl methacrylate (GMA) on silica gel particles, obtaining the grafted particles PGMA/SiO2 with a high PGMA grafting degree (about 26 g/100 g) . The effects of the main factors on the graft polymerization of GMA were examined and the corresponding mechanism was investigated. The functionalization transformations of the grafted particles PGMA/SiO2 were conducted via ring-opening reaction of the epoxy groups with 5-aminosalicylic acid (5-ASA) and iminodiacetic acid (IDAA) as reagents, respectively, obtaining two functional composite materials, SA-PGMA/SiO2 and IDAA-PGMA/SiO2. The new route of surface-initiated graft-polymerization is feasible and effective. The suitable temperature is 55 °C and the appropriate used amount of BPO is 1.0 % of the monomer mass. The grafted particles PGMA/SiO2 are easy to be transformed into functional composite particles via the ring-opening reaction of epoxy groups. SA-PGMA/SiO2 particles have excellent extracting ability for alkaloids, and have an adsorption capacity of 87 mg/g for matrine; IDAA-PGMA/SiO2 particles have strong chelating adsorption action for heavy metal ions, and have an adsorption capacity of 360 mg/g for Pb2+ ion.

COVALENT IMMOBILIZATION OF GLUCOSE OXIDASE ON WELL-DEFINED POLYMER-SILICON WAFER HYBRIDS VIA SURFACE-INITIATED RAFT-MEDIATED PROCESS

A surface modification technique was developed for the functionalization of silicon surface with glucose oxidase (GOD). The silicon surface was first graft copolymerized with glycidyl methacrylate (GMA) via surface-initiated reversible addition-fragmentation chain-transfer (RAFT)-mediated process. GOD was then covalently immobilized through the ring-opening reaction between the amine groups of the GOD and the epoxide groups of the grafted GMA polymer chains. X-ray photoelectron spectroscopy (XPS) was used to characterize the surface-modified surface after each modification stage. Increasing the thickness of the polymer layer and the immobilization time could allow a great amount of GOD to be immobilized on the silicon surface. The GOD-functionalized silicon hybrids are promising candidates for the silicon-based glucose biosensors. 1-4 It is of great importance to improve the biocompatibility of the silicon microdevices and to develop silicon surfaces with controllable cell adhesion. Immobilization of biomolecules on silicon substrates can be achieved via many methods such as adsorption, entrapment, covalent binding, etc. Functionalization of silicon surface with organics is a key in the development of new silicon-based biomedical devices. Tethering of polymer brushes on the solid substrate is an effective method of modifying the surface of the various substrates. 5-6 The dense polymer brushes can alter the properties of the surface, supply excellent mechanical and chemical protection to the substrate, and indicate new pathways to the functionalization of silicon surfaces for molecular recognition and sensing. 7-10 USA). The silicon wafers were cut into square chips of about 1.2 cm × 1.2 cm in size. The monomer, GMA, was passed through inhibitor-removing columns and then stored under an argon atmosphere at -10 °C. The initiator a,a'-azobis(isobutyronitrile) (AIBN, 97%) was obtained from Kanto Chemical Co. (Tokyo, Japan) and was recrystallized in anhydrous ethanol. The silane coupling agent (3-(trimethoxysilyl) propyl methacrylate (TMSPM, 98%)) was obtained from Aldrich Chemical Co. (St. Louis, MO, USA). The chain transfer agent (CAT), 1-phenylethyl dithiobenzoate (PDB), was synthesized according to the published procedures.19 GOD (Type II, 15500 units g-1 from Aspergillus niger) was purchased from Sigma Chemical Co. (St. Louis, MO, USA). Dulbecco's phosphate buffer solution (PBS, pH=7.4) was freshly prepared. Bio-Rad dye reagent for protein assay (Catalog No. 500-0006) was obtained from BioRad (Hercules, CA, USA). The other reagents were of analytical grade and were used without further purification unless otherwise mentioned. Immobilization process The process of surface functionalization of silicon was shown in Fig. 1. Coupling of the RAFT initiator to the silicon wafer was first achieved by adding TMSPM (0.41 mmol), AIBN (0.23 mmol), and PDB (0.46 mmol) at a molar ratio of 1.8:1:2 into 5 mL of dry DMF in a Pyrex tube containing the silicon chip. After purging the mixture with argon for 30 min, the surface coupling reaction continued at 60 °C for 24 h under an argon atmosphere. After the reaction, the modified substrate was washed with CH 2 Cl 2 and then with an ethanol/water mixture.

Prepared Polymethacrylate-Based Monoliths for the Separation of Cations by Non-Suppressed Capillary Ion Chromatography

This paper describes a novel analytical system for non-suppressed capillary ion chromatography. Methacrylate monolithic columns were prepared from silanized fused-silica capillaries of 320 µm i.d. by in situ polymerization of glycidyl methacrylate and ethylene dimethacrylate in the presence of 1,4-butanediol, 1-propanol and water as the porogen solvents. The introduction of cation-exchange sites was achieved by sulfonating the matrix with sodium sulfite to produce total cation-exchange capacities in the range of 45-105 μequiv/mL for a 25 cm column. The conditions (concentrations of sodium sulfite solution, reacting time and modified flow rate) of sulfonation were optimized. The hydrodynamic and chromatographic performances were estimated. Coupled with a conductivity detector, a capillary ion chromatography system was set up with the prepared column. Finally, the resultant column was used for the separations of five common univalent cations (Li(+), Na(+), NH4(+), K(+) and Cs(+)) using methanesulfonic acid as the eluent and four divalent cations (Mg(2+), Ca(2+), Sr(2+) and Ba(2+)) by non-suppressed capillary ion chromatography; the chromatographic parameters were further researched.

Synthesis, characterization, and micellization of cholesteryl-modified amphiphilic poly(L-lactide)-block-poly(glycidyl methacrylate) as a nanocarrier for hydrophobic drugs

The biodegradable polymer cholesteryl-(L-lactic acid)50, CLA50, was synthesized via ring-opening polymerization of L-lactide in the presence of cholesterol as an initiator and a catalytic amount of Sn(Oct)2. The resulting monohydroxyl-terminated CLA50 was subsequently converted to a bromine-ended macroinitiator (CLA50–Br) by esterification with 2-bromisobutyryl bromide. The amphiphilic diblock copolymer CLA50-b-PGMA was then synthesized via atom transfer radical polymerization of glycidyl methacrylate (GMA). The resulting polymers were characterized by FTIR, 1H NMR, GPC, and DSC. Polymeric micelles were prepared by the co-solvent evaporation method. The aqueous self-assembly of the copolymer CLA50-b-PGMA was investigated by TEM and DLS. Using naproxen as a hydrophobic model drug, drug-loaded micelles were prepared. TEM images of naproxen-loaded micelles of the copolymer (which exhibited a loading efficiency of 76.5 % and a loading capacity of 15.3 %) showed that the micelles were spherical and had diameters of 29–40 nm. An in vitro release study of naproxen was performed using the dialysis method in a phosphate-buffered solution at 37 °C. According to the results obtained in this work, these polymeric micelles could be tailored (by modifying the copolymer composition and molecular weight of blocks) to act as effective drug carriers that facilitate the release of various drugs.

Covalent Functionalization of Silica Nanoparticle with Poly(glycidyl methacrylate) via ATRP at Ambient Temperature

The silica nanoparticle was covalently functionalized with toluene-2,4-diisocyanate to prepare the functionalized silica nanoparticle containing isocyanate group. Here, the isocyanate group on the functionalized silica nanoparticle have been further derivatized with water and 2-bromoisobutyryl bromide consecutively resulting in the attachment of atom transfer radical polymerization initiators to the surface of the silica nanoparticle. These silica nanoparticle based macroinitiators were used to initiate polymerization of glycidyl methacrylate at ambient temperature in aqueous media. Thus, structurally well-defined poly(glycidyl methacrylate) was grown from the silica nanoparticle surface to yield individual hybrids composed of a silica core and a well-defined, densely grafted outer poly(glycidyl methacrylate) via atom transfer radical polymerization. FTIR spectroscopy was utilized to follow the covalent functionalization of silica nanoparticle and showed the formation of resulting hybrid particle.

Electrochemical DNA biosensor based on IL‐modified MWNTs electrode prepared by radiation‐induced graft polymerization

AbstractElectrochemical DNA (E‐DNA) biosensors were fabricated by the physical immobilization of probe DNA, 5′‐GGA GCT GCT GGC ATT ATT GAA‐3′, on ionic‐liquid‐multiwalled carbon nanotubes (IL‐MWNTs) modified with indium tin oxide (ITO) electrodes to detect Salmonella typhi (S. typhi). IL‐MWNTs were prepared by the introduction of 1‐butylimidazole bromide onto an epoxy group on poly(GMA)‐grafted MWNTs, which were synthesized by radiation‐induced graft polymerization of glycidyl methacrylate (GMA) onto MWNTs in aqueous solution. Subsequently, IL‐MWNTs were coated onto the ITO electrode surface, and then the physical immobilization of the probe DNA performed in probe DNA solution at room temperature for 1 h. The IL‐MWNTs were characterized by elemental analysis, XPS, and TGA. The electron transfer resistance (Ret) of the E‐DNA biosensor was evaluated after hybridization of the probe DNA and target DNA using electrochemical impedance spectroscopy. The Ret increased after the hybridization of probe DNA and target DNA. The DNA used was complementary DNA: 5′‐TTC AAT AAT GCC AGC AGC TCC‐3′, single‐base mismatch DNA: 5′‐TTC AAT AAT GGC AGC AGC TCC‐3′ and three‐base mismatch DNA: 5′‐TTC ATT AAT GGC AGC ACG TCC‐3′. The dynamic detection range for the sequence‐specific DNA of target DNA was from 1.0 × 10−13 to 1.0 × 10−10 mol L−1 with a regression equation Ret (Ω) = 18.6 C + 128 and regression coefficient (γ) of 0.996. The detection limit was determined to be 3.1 × 10−14 mol L−1. The results demonstrated that the sensitivity of this impedance‐based DNA sensor was sufficient for the target DNA sequence detection. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012

Chemically modified diamond-like carbon (DLC) for protein enrichment and profiling by MALDI-MS

The development of new high throughput methods based on different materials with chemical modifications for protein profiling of complex mixtures leads towards biomarkers; used particularly for early diagnosis of a disease. In this work, diamond-like carbon (DLC) is developed and optimized for serum protein profiling by matrix-assisted laser/desorption ionization mass spectrometry (MALDI-MS). This study is carried out in connection with a material-based approach, termed as material-enhanced laser desorption ionization mass spectrometry. DLC is selected as carrier surface which provides large surface to volume ratio and offers high sensitivity. DLC has a dual role of working as MALDI target while acting as an interface for protein profiling by specifically binding peptides and proteins out of serum samples. Serum constituents are bound through immobilized metal ion affinity chromatography (IMAC) functionality, created through glycidyl methacrylate polymerization under ultraviolet light followed by further derivatization with iminodiacetic acid and copper ion loading. Scanning electron microscopy highlights the morphological characteristics of DLC surface. It could be demonstrated that IMAC functionalized DLC coatings represent a powerful material in trapping biomolecules for their further analysis by MALDI-MS resulting in improved sensitivity, specificity and capacity in comparison to other protein-profiling methods.

Ring opening polymerization of glycidyl methacrylate by Maghnite-H+ a solid catalyst

In the present work the ring-opening polymerization of glycidyl methacrylate (GMA) using Maghnite-H+, a proton exchanged montmorillonite clay as initiator is reported. The influences of solvent, weight ratio of initiator/monomer and reaction time on the conversion of monomer and on the molecular weight are investigated. Increasing Maghnite-H+ proportion increases (GMA) conversion and decreases the average molecular weight of resulted polymer. A cationic mechanism for the reaction was proposed.

Preparation and Characterization of Magnetic Strong-Base Anion Exchange Resin

The magnetic copolymer was prepared by polymerization of glycidyl methacrylate (GMA) and divinylbenzene (DVB) in the presence of OA-modified magnetic nano-particles. The magnetic strong-base anion exchange resin (MAER) was formed by quaternization of magnetic copolymer. Transmission electron microscope (TEM) and scanning electron microscope (SEM) were used for observation of prepared magnetic nano-particle and MAER, respectively. FT-IR spectrometer was used to characterize the magnetic nano-particle and MAER. To explore the potential application of MAER for natural organic matter (NOM) removal, completely-mixed (CMC) mode was used for humic acid (HA) adsorption. It was found that the HA removal for CMC mode with MAER resin was 10~20% higher than conventional process before breakthrough.

Atom transfer radical polymerization of functional monomers employing Cu‐based catalysts at low concentration: Polymerization of glycidyl methacrylate

AbstractInitiators for continuous activator regeneration atom transfer radical polymerization (ICAR ATRP) of an epoxide‐containing monomer, glycidyl methacrylate (GMA), was successfully carried out using low concentration of catalyst (ca. 105 ppm) at 60 °C in anisole. The copper complex of tris(2‐pyridylmethyl)amine was used as the catalyst, diethyl 2‐bromo‐2‐methylmalonate as the initiator, and 2,2′‐azobisisobutyronitrile as the reducing agent. When moderate degrees of polymerization were targeted (up to 200), special purification of the monomer, other than removal of the polymerization inhibitor, was not required to achieve good control. To synthesize well‐defined polymers with higher degrees of polymerization (600), it was essential to use very pure monomer, and polymers of molecular weights exceeding 50,000 g mol−1 and Mw/Mn = 1.10 were prepared. The developed procedures were used to chain‐extend bromine‐terminated poly(methyl methacrylate) macroinitiator prepared by activators regenerated by electron transfer (ARGET) ATRP. The SnII‐mediated ARGET ATRP technique was not suitable for the polymerization of GMA and resulted in polymers with multimodal molecular weight distributions. This was due to the occurrence of epoxide ring‐opening reactions, catalyzed by SnII and SnIV. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011

Kinetics of radical polymerization of glycidyl methacrylate initiated by multi‐site phase transfer catalyst–potassium peroxydisulfate in two‐phase system

AbstractThe kinetics of radical polymerization of glycidyl methacrylate, initiated by the free radicals formed in situ in the multi‐site phase transfer catalyst (PTC), 1,1,2,2‐tetramethyl‐1‐benzyl‐2‐n‐propylethylene‐1,2‐diammonium bromide chloride–potassium peroxydisulfate system was studied in an aqueous–organic two‐phase media at 60°C ± 1°C under inert and unstirred condition. The rate of polymerization (Rp) was determined at various concentrations of the monomer, initiator, catalyst, and volume fraction of aqueous phase. The effect of acid, ionic strength, and water‐immiscible organic solvents on the Rp was examined. The temperature dependence of the rate was studied, and activation parameters were calculated. Rp increased with an increase in the concentrations of monomer, initiator, multi‐site PTC, and increase in the polarity of solvent and temperature. The order with respect to monomer, initiator, and multi‐site PTC was found to be 0.50. A feasible free‐radical mechanism consistent with the experimental data has been proposed, and its significance was discussed. The synthesized polymer was confirmed by Fourier transform infrared spectral analysis. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

Protein‐functionalized ultrathin glycidyl methacrylate polymer grafts on gold for the development of optical biosensors : an SPR investigation

AbstractThis contribution describes the use of surface plasmon resonance (SPR) technique to fully characterize polymer‐based immunosensing surfaces. Bovine serum albumin (BSA), selected as model biomacromolecule probe, was covalently immobilized on a gold substrate via a poly(glycidyl methacrylate) (PGMA) thin film. Optical characterization was performed at the various steps of the sensor preparation and application. SPR measurements were performed first in static mode to characterize both PGMA and BSA films as well as in dynamic mode to monitor the immunocapture of antibovine serum albumin (a‐BSA) and further study the regenerability of the surface at the level of the antigen layer. Effect of the preparation method of PGMA films, based on either grafting‐onto or grafting‐from approaches, on the immunosensor efficiency was studied. In all cases, the sensing surface could be efficiently regenerated by using an acidic glycine solution without noticeable loss of activity demonstrating the usefulness of poly(glycidyl methacrylate) spacers. Copyright © 2010 John Wiley &amp; Sons, Ltd.

Palladium(0) nanoparticles formed in situ in the Suzuki–Miyaura reaction: The effect of a palladium(II) precursor

Two palladium catalyst precursors were prepared by immobilizing PdCl 2 and Pd(OAc) 2 on cyclohexyldiamine-modified glycidyl methacrylate polymer (GMA-CHDA) and used in the Suzuki–Miyaura reaction (80 °C, 2 h) without any pre-treatment. Using the TEM, SEM, EDS, and XPS methods, we were able to characterize the Pd(0) nanoparticles formed in situ during the catalytic process. The catalyst obtained from Pd(OAc) 2 (P 2) contained Pd(0) nanoparticles with a diameter of 3–5 nm, whereas much bigger agglomerates were found for P 1, which had been obtained from PdCl 2. The P 2 catalyst exhibited much better catalytic performance than P 1, pointing to an important role of the palladium precursor in the preparation of the catalyst.