Aqueous free-radical polymerization of PEGMEMA macromer: kinetic studies via an on-line 1H NMR technique

Najafi, Vahid; Ziaee, Farshid; Kabiri, Kourosh; Mehr, Mohammad Jalal Zohouriaan; Abdollahi, Hossein; Nezhad, Pezhman Mosalla; Jalilian, Seyed Mehrdad; Nouri, Azita

doi:10.1007/s13726-012-0072-8

Cited by 12 publications

(5 citation statements)

References 21 publications

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“…1 H NMR spectra of the all of the co-monomers PEGMEM contain characteristic following the signals given in ppm of the =CH (H Ac-m ) at ca. δ = 6.06, =CH (H Bc-m ), δ = 5.63, -CH 2 OCO (H Cc-m ), δ = 4.24, -OCH 2 CH 2 - (H Dc-m ) in the range δ = 3.42–3.87, –OCH 3 (H Ec-m ), at δ = 3.27, and –CH 3 (H Fc-m ), and at δ = 1.83 [ 64 , 65 , 66 ].…”

Section: Resultsmentioning

confidence: 99%

Influence of the Poly(ethylene Glycol) Methyl Ether Methacrylates on the Selected Physicochemical Properties of Thermally Sensitive Polymeric Particles for Controlled Drug Delivery

2022

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Thermosensitive copolymers P1–P5 of N-isopropylacrylamide (NIPA) and poly(ethylene glycol) methyl ether methacrylates (PEGMEMs) were synthesized via surfactant-free precipitation polymerization (SFPP) using ammonium persulfate (APS) at 70 °C. The polymerization course was evaluated by the conductivity. The hydrodynamic diameters and the polydispersity indexes (PDI) of P1–P5 in the 18–45 °C range, which were assessed via dynamic light scattering (DLS), were at 18° (nm): 26.07 ± 0.54 (PDI 0.65 ± 0.03), 68.00 ± 1.10 (PDI 0.56 ± 0,02), 45.12 ± 0.57 (PDI 0.51 ± 0.03), 62.78 ± 0.40 (PDI 0.53 ± 0.003), and 92.95 ± 1.56 (PDI 0.60 ± 0.04), respectively. The lower critical solution temperatures ranged from 31 to 33 ℃. The electrophoretic mobilities estimated the zeta potential in the 18–45 °C range, and at 18 °C, they were (mV): −4.64 ± 1.30, −6.91 ± 2.67, −5.85 ± 3.17, −2.28 ± 0.30, and −3.60 ± 0.96 for P1–P5, respectively. The polymers were characterized by Attenuated Total Reflectance Fourier-Transform Infrared spectroscopy (ATR-FTIR), H nuclear magnetic resonance (1H NMR), thermogravimetric analysis (TGA/DTA), Differential Scanning Calorimetry (DSC), and powder X-ray diffraction analysis (PXRD). Stable amorphous polymers were obtained. We conclude that the length of the co-monomer chain nonlinearly influences the properties of the obtained thermosensitive polymer nanostructures.

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Section: Resultsmentioning

confidence: 99%

Influence of the Poly(ethylene Glycol) Methyl Ether Methacrylates on the Selected Physicochemical Properties of Thermally Sensitive Polymeric Particles for Controlled Drug Delivery

2022

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“…The spectrum was recorded every 2 min during the first 16 min and then every 10 or 15 min for 3 h. Monomer conversion of MAA and PEGMA were calculated based on the evolution of the peaks corresponding to the vinyl protons of MAA (δ, 5.60, 5.25, ppm) and PEGMA (δ, 6.10, 5.70, ppm). The peak related to the methoxy group protons (δ, 3.30, ppm), which is present in the PEGMA macromonomer side chain, was selected as internal reference [36]. Figure 1 illustrates the change on the intensity of the MAA and PEGMA peaks over copolymerization time.…”

Section: Copolymerization Reactionsmentioning

confidence: 99%

Kinetics of the Aqueous-Phase Copolymerization of MAA and PEGMA Macromonomer: Influence of Monomer Concentration and Side Chain Length of PEGMA

et al. 2017

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An in situ nuclear magnetic resonance spectroscopy (NMR) technique is used to monitor the aqueous-phase copolymerization kinetics of methacrylic acid (MAA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) macromonomers. In particular, the study analyses the effect of the number of ethylene glycol (EG) groups along the lateral chains of PEGMA and is carried out under fully ionized conditions of MAA at different initial monomer ratios and initial overall monomer concentrations (5-20 wt % in aqueous solution). The composition drift with conversion indicates that PEGMA macromonomer is more reactive than MAA. Individual monomer consumption rates show that the rates of consumption of both monomers are not first order with respect to overall concentration of the monomer. The reactivity ratios estimated from the copolymerization kinetics reveal, that for the short PEGMA, the reactivity ratios r MAA and r PEGMA increase with the solids content (SC). A totally different trend is obtained for the longer PEGMA, whose reactivity ratio (r PEGMA23 ) decreases with solids content, whereas the reactivity ratio of MAA remains roughly constant.

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“…The nuclear magnetic resonance (NMR) spectroscopic analysis was carried out to infer information on the polymerization of GMA and PEGMA, as discussed in Figure . In 1 H NMR spectrum, the signal appeared at δ 0.89 ppm, confirming the presence of methyl (−CH 3 ) protons in the PEGMA and GMA unit, and a singlet at δ 3.75 corresponds to the methoxy (−OCH 3 ) group presence in the PEGMA. The peak at δ 3.6 ppm is the respective methylene (−CH 2 ) group of the polyethylene units.…”

Section: Resultsmentioning

confidence: 99%

Win–Win Approach Toward Chrome-Free and Chrome-Less Tanning with Waterborne Epoxy Polymers: A Sustainable Way To Curb the Use of Chrome

Madhu,

Mayakrishnan,

Muthu

et al. 2024

ACS Sustainable Chem. Eng.

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Leather, a natural biomaterial sourced from animal skins and hides, is characterized by its intricate three-dimensional collagen fiber network. In this study, we present an innovative approach to stabilize goat skins using chrome-free and chrome-less tanning processes using epoxy polymers to comprehend surface active properties. Comprehensive structural and chemical analyses of the synthesized epoxy polymers were conducted employing Fourier-transform infrared spectroscopy (FT-IR), nuclear magnetic resonance, and gel permeation chromatography (GPC) for molecular weight determination along with particle size analysis in a water emulsion (1−2%). The surface tension was carried out for the surface activity of the polymers. Epoxy tanning yielded leather with a notable shrinkage temperature (T s ) of 80 ± 2 °C, when combined with chrome tanning (3%), bringing T s to 101 °C, similar to that of conventionally processed leather. The combined tanning achieved a significantly higher thickening rate of 108% and higher softness than chrome-tanned leathers. Comprehensive analyses of physical attributes, including tensile strength (26 N mm 2 ), tear resistance (78 N mm), elongation (48%), and shrinkage temperatures, were conducted. Field emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX) were employed to visualize the elemental composition and infer information on the splitting of collagen fibers. This approach of surface active tanning agent in leather processing technology results in improved leather properties with a reduced environmental footprint.

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Aqueous free-radical polymerization of PEGMEMA macromer: kinetic studies via an on-line 1H NMR technique

Cited by 12 publications

References 21 publications

Influence of the Poly(ethylene Glycol) Methyl Ether Methacrylates on the Selected Physicochemical Properties of Thermally Sensitive Polymeric Particles for Controlled Drug Delivery

Influence of the Poly(ethylene Glycol) Methyl Ether Methacrylates on the Selected Physicochemical Properties of Thermally Sensitive Polymeric Particles for Controlled Drug Delivery

Kinetics of the Aqueous-Phase Copolymerization of MAA and PEGMA Macromonomer: Influence of Monomer Concentration and Side Chain Length of PEGMA

Win–Win Approach Toward Chrome-Free and Chrome-Less Tanning with Waterborne Epoxy Polymers: A Sustainable Way To Curb the Use of Chrome

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