Grafting Of Glycidyl Methacrylate Research Articles

Study on Crystal Form Transition and Non-Isothermal Crystallization of Glycidyl Methacrylate Grafted Isotactic Polybutene-1

Abstract We report the impact of grafting glycidyl methacrylate (GMA) at different degrees onto isotactic polybutene-1 (iPB-1) on the crystallization process. The study of the crystal form transition using FTIR and X-ray Diffraction (XRD) revealed that the conversion degree from form II to form I of the grafted iPB-1 (iPB-g-GMA) was higher than that of iPB-1 under the same experimental conditions and increased with increasing grafting degree. The spherulitic size of iPB-g-GMA was smaller compared to iPB-1 at the same amplification factor in Polarized Optical Microscopy (POM). The kinetic parameters of the non-isothermal crystallization process have been determined based on Differential Scanning Calorimetry (DSC) experiments and the Ozawa and Mo equation. The results showed that the crystallization rate of iPB-g-GMA was higher than that of iPB-1. The activation energy for the non-isothermal crystallization process of iPB-g-GMA (with a grafting degree of 1.54%) was lower than that of iPB-1, which further illustrated that grafting GMA on iPB-1 accelerated the crystallization rate.

Effect of reactive functionalization on properties and degradability of poly(lactic acid)/poly(vinyl acetate) nanocomposites with cellulose nanocrystals

Nanocomposites of poly(lactic acid) (PLA) containing cellulose nanocrystals (CNCs) were prepared by dispersion of CNCs in aqueous poly(vinyl acetate) (PVAc) emulsion followed by melt extrusion with PLA. Functionalization of PVAc by radical grafting of glycidyl methacrylate (PVAc-GMA) was carried out during PVAc polymerization by using ammonium cerium (IV) nitrate as the initiator. The morphology, phase interactions, thermal and mechanical properties and degradability in composting of blends (PLA/PVAc, PLA/PVAc-GMA) and nanocomposites (PLA/PVAc/CNC, PLA/PVAc-GMA/CNC) containing 3wt% CNC were examined by FESEM, AFM, FT-IR, DSC and tensile tests. The study of degradability demonstrated that the disintegration rate of PLA/PVAc-GMA/CNC in soil was higher than that of PLA/PVAc/CNC, likely because the epoxy groups of GMA accelerated the biodegradation rate through the formation of radicals.

Catalase immobilized-radiation grafted functional cellulose matrix: A novel biocatalytic system

The work highlights a unique, one step protocol for room temperature immobilization of enzyme catalase onto epoxy functionalised cellulose matrix developed via gamma radiation induced simultaneous irradiation grafting of Glycidylmethacrylate (GMA). Effect of grafting parameters, such as radiation dose, monomer concentration and solvent composition on the grafting yield, was studied in order to optimize the radiation grafting process. Poly(GMA)-g-cellulose matrices were characterized by grafting yield determination, FTIR, SEM and TGA techniques. The epoxy functionalized poly(GMA)-g-cellulose matrix was subsequently employed for covalent immobilization of an industrially relevant enzyme catalase. The catalytic activity of catalase-immobilized-poly(GMA)-g-cellulose was assayed by spectrophotometrically monitoring the enzymatic degradation of H2O2 at 240nm. Catalase-immobilized-poly(GMA)-g-cellulose was observed to be reusable for over 5 cycles within ten days. Catalase was observed to show improved activity at higher pH after immobilization. Thermal stability of Catalase-immobilized-poly(GMA)-g-cellulose was also enhanced in comparison to the free enzyme system.

Controlled grafting of vinylic monomers on polyolefins: a robust mathematical modeling approach

Experimental and mathematical modeling analyses were used for controlling melt free-radical grafting of vinylic monomers on polyolefins and, thereby, reducing the disturbance of undesired cross-linking of polyolefins. Response surface, desirability function, and artificial intelligence methodologies were blended to modeling/optimization of grafting reaction in terms of vinylic monomer content, peroxide initiator concentration, and melt-processing time. An in-house code was developed based on artificial neural network that learns and mimics processing torque and grafting of glycidyl methacrylate (GMA) typical vinylic monomer on high-density polyethylene (HDPE). Application of response surface and desirability function enabled concurrent optimization of processing torque and GMA grafting on HDPE, through which we quantified for the first time competition between parallel reactions taking place during melt processing: (i) desirable grafting of GMA on HDPE; (ii) undesirable cross-linking of HDPE. The proposed robust mathematical modeling approach can precisely learn the behavior of grafting reaction of vinylic monomers on polyolefins and be placed into practice in finding exact operating condition needed for efficient grafting of reactive monomers on polyolefins.

Radiation grafting of glycidyl methacrylate and divinylbenzene onto polyethylene terephthalate fabrics for improving anti-dripping performance

A new kind of anti-dripping polyethylene terephthalate (PET) fabric was successfully prepared by simultaneous gamma radiation-induced grafting polymerization of glycidyl methacrylate (GMA) and divinylbenzene (DVB) onto the surface of PET fabrics. The grafting yield (GY) and anti-dripping effect were optimized by changing the total absorbed dose, dose rate, concentration and the feed ratio of GMA and DVB. The grafting yield increased with the increase of absorbed dose and GMA monomer concentration, and decreased with the dose rate. It is confirmed that PET fabrics had been modified by Fourier transform infrared spectroscopy analysis. The tensile strength and elongation at break of modified PET fabrics were improved compared with original PET fabrics. The limiting oxygen index (LOI) of modified PET fabrics with the GY of 23–25% was 21.5, which was similar to that of unmodified PET fabrics. However, the anti-dripping performance of PET fabrics was improved remarkably after radiation modification due to the crosslinking of the sidechains grafted on the PET surface. This anti-dripping fabric may be promising for fire protective clothing.

Preparation of alkaline polymer catalyst by radiation induced grafting for transesterification of triacetin under neural network optimized conditions

ABSTRACTA simple and flexible method was used to develop new alkaline polymer catalyst through radiation induced grafting of glycidylmethacrylate (GMA) onto polyethylene/polypropylene (PE/PP) nonwoven sheet followed by amination reaction and alkalisation. The chemical structure and morphology of catalyst was evaluated by Fourier transform-infrared (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermal gravimetric analyzer (TGA). The catalyst was examined for the transesterification of triacetin/methanol mixtures in a batch mode and the obtained methyl ester was detected by GC-MS. In order to optimize the reaction parameters towards getting the higher yield, an artificial neural network (ANN) was used to develop a non-linear model correlating the four independent reaction parameters including catalyst dosage, triacetin/methanol molar ratio, reaction time and temperature. The maximum conversion obtained via the simulated annealing (SA) algorithm was 86.2% at the optimal conditions of 5.01 wt% catalyst dosage, triacetin/methanol 1:12 molar ratio, 8 h reaction time and 62.8°C temperature. Upon using these optimal conditions in the experimental reaction, the conversion of as high as 85% was achieved. These results suggest that the simply modified low cost PE/PP fibrous sheet has a potential to catalyze biodiesel production. Moreover, the combined ANN-SA modelling method is highly effective in predicting the conversion of transesterification reaction and optimizing its parameters.

Design of functionalized biodegradable PHA-based electrospun scaffolds meant for tissue engineering applications

Modification of electrospun nanofibrous poly(3-hydroxyalkanoate) (PHA)-based mats was implemented through two routes to obtain biomimetic scaffolds meant for tissue engineering applications. The first strategy relied on a physical functionalization of scaffolds thanks to an original route which combined both electrospinning and electrospraying, while the second approach implied the chemical modification of fiber surface via the introduction of reactive functional groups to further conjugate bioactive molecules. The degree of glycidyl methacrylate grafting on PHA reached 20% after 300s under photoactivation. Epoxy groups were modified via the attachment of a peptide sequence, such as Arg-Gly-Asp (RGD), to obtain biofunctionalized scaffolds. SEM and TEM analysis of mats showed uniform and well-oriented beadless fibers. The electrospinning/electrospraying tandem process afforded highly porous scaffolds characterized by a porosity ratio up to 83% and fibers with a surface largely covered by the electrosprayed bioceramic, i.e. hydroxyapatite. Gelatin was added to the latter PHA-based scaffolds to improve the hydrophilicity of the scaffolds (water contact angle about 0°) as well as their biological properties, in particular cell adhesion, proliferation, and osteogenic differentiation after 5days of human mesenchymal stromal culture. Human mesenchymal stromal cells exhibited a better adhesion and proliferation on the biofunctionalized scaffolds than that on non-functionalized PHA mats.

Preparation of PVDF anionic exchange membrane by chemical grafting of GMA onto PVDF macromolecule

In this research, poly(vinylidene fluoride) (PVDF) anionic exchange membranes were prepared by a method of chemically induced grafting of glycidyl methacrylate (GMA) onto PVDF macromolecule in solution. Various preparation parameters, including initiator, monomer and cross-linker concentrations, grafting time and temperature, drying time of the anionic membranes, were established in correlation with area resistance and anionic permselectivity of the obtained anionic exchange membranes. The chemical and crystal changes of the membranes were characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. Surface morphologies and thermal stability were also evaluated by field emission scanning electron microscopy (FT-SEM) and thermogravimetric analyzer (TGA). The results reveal that a PVDF anionic exchange membrane is successfully prepared by this method and shows excellent properties with area resistance as low as 4.3 Ω⋅cm2 and anionic permselectivity as high as 99%, which are comparable to those of some commercial anionic exchange membranes, such as AHA, AMX, AST and so on. The membranes are homogenous, compact and show great thermal stability up to 171°C and excellent alkali stability.

Comparative study of dielectric and mechanical properties of HDPE-MWCNT-SiO2 nanocomposites

Multiwalled carbon nanotubes (MWCNT⿿s) and Nano-Silicon dioxide (SiO2) reinforced HDPE composites have been developed. The MWCNT and Nano- SiO2 filler content was varied up to 5wt% in HDPE with the addition of Polyethylene grafted glycidyl methacrylate compatibilizer and 3-aminopropyl triethoxy silane coupling agent. The dielectric and mechanical properties of the HPDE nanocomposites have been investigated in this study. Addition of MWCNT and Nano-SiO2 are observed to enhance the tensile strength and modulus of the nano-composites. The electrical properties like breakdown voltage and volume resistivity showed improvement with the addition of Nano-SiO2.

Preparation and characterization of high capacity, strong cation-exchange fiber based adsorbents

Motivated by the demand for more economical capture and polishing steps in downstream processing of protein therapeutics, a novel strong cation-exchange chromatography stationary phase based on polyethylene terephthalate (PET) high surface area short-cut fibers is presented. The fiber surface is modified by grafting glycidyl methacrylate (GMA) via surface-initiated atom transfer radical polymerization (SI-ATRP) and a subsequent derivatization leading to sulfonic acid groups. The obtained cation-exchange fibers have been characterized and compared to commercially available resin and membrane based adsorbers. High volumetric static binding capacities for lysozyme (90mg/mL) and polyclonal human IgG (hIgG, 92mg/mL) were found, suggesting an efficient multi-layer binding within the grafted hydrogel layer. A packed bed of randomly orientated fibers has been tested for packing efficiency, permeability and chromatographic performance. High dynamic binding capacities for lysozyme (50mg/mL) and hIgG (54mg/mL) were found nearly independent of the bed-residence time, revealing a fast mass-transport mechanism. Height equivalent to a theoretical plate (HETP) values in the order of 0.1 cm and a peak asymmetry factor (AF) of 1.8 have been determined by tracer experiments. Additionally inverse size-exclusion chromatography (iSEC) revealed a bimodal structure within the fiber bed, consisting of larger transport channels, formed by the voidage between the fibers, and a hydrogel layer with porous properties.

Radiation induced grafting of glycidyl methacrylate on teflon scrap for synthesis of dual type adsorbent: Process parameter standardisation

High energy Co‐60 gamma radiation has been used to graft glycidylmethacrylate (GMA) onto Teflon scrap by mutual radiation grafting technique. Effect of various experimental parameters viz, solvent, solvent mixture, dose, dose rate, monomer concentration, backbone thickness on grafting extent was investigated. The grafting extent decreased with the dose rate and thickness and increased with concentration of GMA. Among the solvent studied acetone–water mixture in which poly(GMA) was soluble was found to be the best solvent for grafting. A kinetic equation Rg = Kg[M] 1.7 D0.1 relating grafting kinetics to monomer concentration and dose rate was deduced. The matrices were characterized for morphology, thermal stability and dye uptake extent. © 2016 American Institute of Chemical Engineers Environ Prog, 35: 1367–1373, 2016

Grafting glycidyl methacrylate to Sepharose gel for fabricating high-capacity protein anion exchangers

To develop ion exchangers of high protein adsorption capacity, we have herein introduced atom transfer radical polymerization (ATRP) method to graft glycidyl methacrylate (GMA) onto Sepharose FF gel. GMA-grafted Sepharose FF resins of four grafting densities and different grafting chain lengths were obtained by adjusting reaction conditions. The epoxy groups on the grafted chains were functionalized by modification with diethylamine (DEA), leading to the fabrication of Sepharose-based anion exchangers of 14 different grafting densities and/or grafting chain lengths. The resins were first characterized for the effects of grafting density, chain length and ionic strength on pore sizes by inverse size exclusion chromatography. Then, the resins were evaluated by adsorption equilibria of bovine serum albumin (BSA) as a function of ionic capacity (IC) (chain length) at individual grafting densities. It was observed that at each grafting density there was a specific IC value (chain length) that offered the maximum equilibrium capacity. Of the resins with maximum values at individual grafting densities, the resin of the second grafting density with an IC value of 330mmol/L (denoted as FF-Br2-pG-D330) showed the highest capacity, 264mg/mL, about two times higher than that of the traditional ungrafted resin Q Sepharose FF (137mg/mL). This resin also showed the most favorable uptake kinetics among the resins of similar IC values but different grafting densities, or of the same grafting density but different IC values. Effects of ionic strength showed that the capacities of FF-Br2-pG-D330 were much higher than Q Sepharose FF at a wide range of NaCl concentrations (0–200mmol/L), and the uptake rates of the two resins were similar in the ionic strength range. Therefore, the dynamic binding capacity values of BSA on FF-Br2-pG-D330 were much higher than Q Sepharose FF as demonstrated at different residence times and ionic strengths. Taken together, the research has proved the success in the fabrication of high-capacity protein anion exchangers by grafting GMA onto Sepharose gel.

Sorption of acid and basic dyes on radiation-grafted Teflon scrap: equilibrium and kinetic sorption studies

Mutual radiation grafting technique using Co-60 gamma radiation has been used to graft glycidylmethacrylate (GMA) to Teflon scrap. Cationic and anionic adsorbents were prepared from GMA-grafted Teflon scrap (GMA-g-Teflon) by converting epoxy ring into sulphonic acid and triamine groups by doing suitable chemical reactions at elevated temperatures. The converted grafted product was studied for its dye uptake properties from manufactured aqueous dye solution. Uptake of basic dyes namely, Basic red 29 (BR-29) and anionic dye namely, Remazol brilliant blue-1 (RB-1) was investigated. Langmuir and Freundlich adsorption models were used to analyze equilibrium adsorption, while kinetics of adsorption was analyzed using pseudo-first-order, pseudo-second-order models. The equilibrium adsorption of BR-29 and RB-1 was better explained by Langmuir adsorption model. Separation factor (R L ) was found to be in the range 0 < R L < 1, indicating favorable adsorption of basic and acidic dyes. Higher coefficient of determination (or regression) (r 2) and better agreement between q e,cal (calculated) and q e,exp (experimental) values were obtained for pseudo-second-order kinetic model.

Influence of Glycidyl Methacrylate Grafting on the Mechanical, Water Absorption, and Thermal Properties of Recycled High-Density Polyethylene/Rubber Seed Shell Particle Composites

Rubber seed shell (RSS) was modified by grafting treatment using glycidyl methacrylate (GMA) at various concentrations. The RSS was then used to reinforce high-density polyethylene (HDPE). The effects of modification on the mechanical, water absorption, and thermal properties of the RSS/HDPE composites were studied using a mechanical testing instrument, weighing method, Vicat softening temperature (VST) testing, thermogravimetry, and dynamic mechanical analysis. The results showed that the GMA grafting produced an improvement in the flexural and tensile properties of the composites. The water absorption rate of the composites also had an obvious decrease. While a slight increase in VST was found, the various concentrations of GMA showed no improvement in VST. GMA modification also could elevate the thermal stability of the composites at the initial decomposition stage. The optimum grafting concentration of GMA (2.5%) led to the lowest thermal weight loss (37.07% and 26.56%) during the first and second decomposition stages. The E’ values of the composites had a significant increase with the addition of GMA. There were two peaks of tan δ for the untreated samples, but the modified samples exhibited a shift in the transition peak at higher temperatures; moreover, the second peak disappeared.

Radiation synthesis of a new amidoximated UHMWPE fibrous adsorbent with high adsorption selectivity for uranium over vanadium in simulated seawater

A new kind of highly efficient adsorbent material has been fabricated in this study for the purpose of extracting uranium from seawater. Ultra-high molecular weight polyethylene (UHMWPE) fiber was used as a trunk material for the adsorbent, which was prepared by a series of modification reactions, as follows: (1) grafting of glycidyl methacrylate (GMA) and methyl acrylate (MA) onto UHMWPE fibers via Co-60 gamma-ray pre-irradiation; (2) aminolyzation of UHMWPE fiber by the ring-opening reaction between of epoxy groups PGMA and ethylene diamine (EDA); (3) Michael addition of amino groups with acrylonitrile (AN) to yield nitrile groups; (4) amidoximation of the attached nitrile moieties by hydroxylamine in dimethyl sulfoxide-water mixture. Modified UHMWPE fibers were characterized by means of attenuated total reflectance-Fourier transformed infrared spectroscopy (ATR-FTIR), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) to confirm the attachment of amidoxime (AO) groups onto the UHMWPE fibers. The results of X-ray diffraction (XRD) and single fiber tensile strength verified that the modified UHMWPE fiber retained excellent mechanical properties at a low absorbed radiation dose. The adsorption performance of the UHMWPE fibrous adsorbent was evaluated by subjecting it to an adsorption test in simulated seawater using a continuous-flow mode. The amount of uranium adsorbed by this AO-based UHMWPE fibrous adsorbent was 1.97 mg-U/g after 42 days. This new adsorbent also showed high selectivity for the uranyl ion, and its selectivity for metal ions was found to decrease in the following order: U > Cu > Fe > Ca > Mg > Ni > Zn > Pb > V > Co. The adsorption selectivity for uranium is significantly higher than that for vanadium. In addition, preparation of this modified adsorbent consumes much smaller amounts of the toxic acrylonitrile monomer than the conventional preparation methods of AO-based polyethylene fibers. (C) 2016 Published by Elsevier Ltd.

Effect of poly (lactic acid)‐graft‐glycidyl methacrylate as a compatibilizer on properties of poly (lactic acid)/banana fiber biocomposites

The main aim of this study was to synthesis of poly (lactic acid) (PLA)‐graft‐glycidyl methacrylate (GMA) as well as its influence on the properties of PLA/banana fiber biocomposites. PLA‐graft‐GMA graft copolymer (GC) was synthesized by melt blending PLA with GMA using benzoyl peroxide and dicumyl peroxide as initiators. Graft copolymerization was confirmed by FTIR and 1H‐NMR spectroscopic studies. PLA/silane treated banana fiber (SiB) biocomposites with various GC concentrations were prepared by melt blending followed by injection molding techniques. The influence of GC content on the mechanical, thermal and moisture resistance properties of the composite was investigated. The addition of 15 wt% GC content in the biocomposite provided optimum tensile and flexural strength, which is attributed to the greater compatibility between fiber and PLA matrix. The thermal properties of biocomposites have been evaluated using thermogravimetric analysis which provided evidence of improved interfacial adhesion between SiB and PLA by the addition of GC. Additionally, GC enhanced the moisture absorption resistance of biocomposites. These results indicated that GC is indeed a good candidate as a compatibilizing agent to improve the compatibility in PLA/fiber biocomposites. Copyright © 2015 John Wiley &amp; Sons, Ltd.

Effect of lignin nanoparticles and masterbatch procedures on the final properties of glycidyl methacrylate-g-poly (lactic acid) films before and after accelerated UV weathering

This article reports the preparation, by means of an innovative masterbatch procedure, of poly (lactic acid) (PLA)/lignin nanoparticles (LNP) films via premixing 1%wt. of LNP into PLA or glycidyl methacrylate (GMA) grafted PLA (g-PLA). These films were obtained by reactive extrusion and subsequent filmature process. Films obtained by using the masterbatch steps were characterized and compared with the system realized by direct extrusion of 1%wt. of LNP in PLA/g-PLA. Thermal, optical and mechanical properties, as well as morphology of LNP reinforced PLA nanocomposites, were characterized. The performance of the produced films was also investigated after accelerated UV weathering (up to 480h), with the aim of verify how the presence of lignin nanoparticles could modify transparency and mechanical performance of neat (and GMA grafted) PLA films. Results from UV–vis characterization showed how LNP better behave as UV light barrier in grafted PLA, and it has been also proved that GMA grafting onto PLA matrix promoted the dispersion of LNP in matrix. Mechanical tests after weathering also confirmed that both the presence of LNP and GMA accelerates the oxidation effect, since the increased deformability observed for systems containing 1%wt. of LNP in PLA and g-PLA systems at time 0 was lost after 240h of UV exposure.

Efficient removal of Cu(II) using amino‐functionalized superparamagnetic nanoparticles prepared via SI‐ATRP

ABSTRACTAn amino‐functionalized nano‐adsorbent (DETA‐MNPs) was prepared by a process involving: (1) synthesis of superparamagnetic Fe3O4 nanoparticles; (2) introduction of amino groups after which ATRP initiator was anchored; (3) grafting of glycidyl methacrylate (GMA) via SI‐ATRP; and (4) ring‐opening reaction of epoxy groups with diethylenetriamine (DETA). The nano‐adsorbent was characterized by Fourier transform infrared spectroscopy (FT‐IR), X‐ray diffraction (XRD), transmission electron microscope (TEM), and vibrating sample magnetometer (VSM) and applied to remove Cu(II) in batch experiments. The effects of pH, Cu(II) concentrations, solution ionic strength, and contact time were investigated. The results show that the DETA‐MNPs are spherical with cubic spine structure, high saturation magnetization (41.9 emu g−1), and an average diameter of 10 nm. The maximum Cu(II) adsorption capacity achieves 83.33 mg g−1 at pH 5.0 by Langmuir model. The adsorption process is highly pH‐dependent and reaches equilibrium within 20 min. Furthermore, the DETA‐MNPs exhibit excellent dispersibility and reusability. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 132, 42859.

Modification of Lithium Ion Battery Separators by Electron Beam Radiation Induced Grafting of Glycidyl Methacrylate onto Porous PP Film

Modification of Lithium Ion Battery Separators by Electron Beam Radiation Induced Grafting of Glycidyl Methacrylate onto Porous PP Film

Recovery of Au(III) by radiation synthesized aminomethyl pyridine functionalized adsorbents based on cellulose

Three novel n-aminomethylpyridine (n-AMP, n=2, 3, 4) functionalized adsorbents (n-AMPRs) for recovery of Au(III) were synthesized by radiation grafting of glycidyl methacrylate (GMA) onto microcrystalline cellulose microsphere, followed by ring-opening processes with n-AMP. The FTIR and XPS spectra manifested that n-AMP were successfully introduced into the novel adsorbents. Batch and column mode adsorption experiments against Au(III) were conducted to evaluate the adsorption abilities of the adsorbents. The adsorption isotherms of Au(III) were well fitted with Langmuir mode, and adsorption kinetics were well described by pseudo-second-order model. The results presented that n-AMPRs exhibited good adsorption abilities for Au(III) with adsorption capacities in the order of 2-AMPR>3-AMPR>4-AMPR. Moreover, the different adsorption abilities of three n-AMPRs for Au(III) ion were studied by DFT calculations. The adsorbents adsorbed Au(III) ion through anion exchange combined with chelation process, after which a particular reduction process for loaded Au(III) ion was also found. The dynamic experiment revealed that Au(III) in HCl media could be efficiently adsorbed by 2-AMPR in perturbation of equal amounts of Cu(II), Ni(II) and Cr(III), which demonstrated that 2-AMPR would be a promising adsorbent for trace amount of Au(III) ion from industrial effluents and e-wastes.