scholarly journals A Novel Green Synthesis Method of Poly (3-Glycidoxypropyltrimethoxysilane) Catalyzed by Treated Bentonite

2020 ◽  
Vol 15 (2) ◽  
pp. 290-303
Author(s):  
Nadia Embarek ◽  
Nabahat Sahli
Keyword(s):  
Ring Opening ◽  
Low Cost ◽  
Synthesis Method ◽  
Bulk Polymerization ◽  
Scanning Calorimetry ◽  
Epoxy Ring ◽  
Polymer Yield ◽  
Epoxy Ring Opening ◽  
Ft Ir

The present work focuses on the preparation and characterization of poly(3-Glycidoxypropyltrimethoxysilane) (PGPTMS) under mild conditions. Ring-opening polymerization of the 3-Glycidoxypropyltrimethoxysilane (GPTMS) is initiated with the bentonite of Maghnite-H+ (Mag-H+), an ecologic and low-cost catalyst. The evolution of epoxy ring-opening was studied in bulk and in solution using CH2Cl2 as solvent, as well as the influences of several factors such as the amount of Mag-H+, polymerization time and temperature on the yield of polymer were investigated. The best polymer yield (30 %) was obtained in bulk polymerization at room temperature (20 °C) for a reaction time 8 h, and it’s increases with time and reaches 68 % for 7 days. The structures of the obtained polymers (PGPTMS) were confirmed respectively by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (NMR). The thermal properties of the prepared polymers were given by Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA), the Tg of PGPTMS is recorded at -31.27 °C, and it is thermally stable with a degradation start temperature greater than 300 °C, all  decomposition stopped at 600 °C. Copyright © 2020 BCREC Group. All rights reserved

scholarly journals Polyols Prepared from Ring-Opening Epoxidized Soybean Oil by a Castor Oil-Based Fatty Diol

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jing Zhang ◽  
Ji Jun Tang ◽  
Jiao Xia Zhang
Keyword(s):  
Soybean Oil ◽  
Castor Oil ◽  
Ring Opening ◽  
Epoxidized Soybean Oil ◽  
Epoxy Ring ◽  
Molecular Weights ◽  
Molar Ratios ◽  
Epoxy Ring Opening ◽  
Ft Ir

Several biorenewable vegetable oil-based polyols with different molecular weights and various hydroxyl functionalities were successfully prepared by ring-opening epoxidized soybean oil with a castor oil-based fatty diol. It was found that several factors, including reaction time, reaction temperature, and molar ratios between epoxidized soybean oil and castor oil diol, affect structures and rheology behaviors of the final polyols. Proton NMR, FT-IR, GPC, and rheometry results revealed that the hydroxyl functionalities, molecular weight, and viscosity of the polyols could be tailored by controlling the above-mentioned factors. Besides, the role of solvents in the epoxy ring-opening process was investigated as well.

scholarly journals Tailored Crosslinking Process and Protective Efficiency of Epoxy Coatings Containing Glycidyl-POSS

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 591 ◽  
Author(s):  
Mirjana Rodošek ◽  
Mohor Mihelčič ◽  
Marija Čolović ◽  
Ervin Šest ◽  
Matic Šobak ◽  
...  
Keyword(s):  
Ring Opening ◽  
Protective Coatings ◽  
Diglycidyl Ether ◽  
Scanning Calorimetry ◽  
Protective Efficiency ◽  
Crosslinking Process ◽  
Operational Temperature ◽  
Epoxy Ring Opening ◽  
Ft Ir ◽  
Oligomeric Silsesquioxane

Versatile product protective coatings that deliver faster drying times and shorter minimum overcoat intervals that enable curing at faster line speeds and though lower energy consumption are often desired by coating manufacturers. Product protective coatings, based on silsesquioxane-modified diglycidyl ether of bisphenol-A (DGEBA) epoxy resin, are prepared through a glycidyl ring-opening polymerization using dicyandiamide (DICY) as a curing agent. As silsesquioxane modifier serves the octaglycidyl-polyhedral oligomeric silsesquioxane (GlyPOSS). To decrease the operational temperature of the curing processes, three different accelerators for crosslinking are tested, i.e., N,N-benzyl dimethylamine, 2-methylimidazole, and commercial Curezol 2MZ-A. Differential scanning calorimetry, temperature-dependent FT-IR spectroscopy, and rheology allow differentiation among accelerators’ effectiveness according to their structure. The former only contributed to epoxy ring-opening, while the latter two, besides participate in crosslinking. The surface roughness of the protective coatings on aluminum alloy substrate decreases when the accelerators are applied. The scanning electron microscopy (SEM) confirms that coatings with accelerators are more homogeneous. The protective efficiency is tested with a potentiodynamic polarization technique in 0.5 M NaCl electrolyte. All coatings containing GlyPOSS, either without or with accelerators, reveal superior protective efficiency compared to neat DGEBA/DICY coating.

scholarly journals Synthesis and characterization of linear and crosslinked polymers with the addition of DMSPS

2019 ◽  
Vol 73 (1) ◽  
pp. 1
Author(s):  
Karolina Fila ◽  
Beata Podkościelna
Keyword(s):  
Spectroscopic Analysis ◽  
Bulk Polymerization ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Chemical Structures ◽  
Hardness Tests ◽  
Ft Ir ◽  
The Impact ◽  
Sulfur Containing

<p>The aim of this research was the synthesis of polymers with the addition of S,S'-thiodi-4,1-phenylene bis(thiomethacrylate) (DMSPS) by bulk polymerization. Styrene (St), divinylbenzene (DVB) and ethylene glycol dimethacrylate (EGDMA) were used for the copolymerization as main monomers. The chemical structures of sulfur-containing polymers were confirmed by the spectroscopic analysis (ATR/FT-IR). In order to determine the impact of the sulfur derivative (DMSPS) addition on thermal properties of the obtained copolymers, differential scanning calorimetry (DSC) was performed. The hardness tests of the obtained copolymers were also applied using a Shore durometer.</p>

Preparation and Characterization of Compounds Based on Poly(hydroxymethylacrylamide) and Post-consumer Polypropylene

2016 ◽  
Vol 10 (3) ◽  
pp. 291-298 ◽  
Author(s):  
Ilma Cirne ◽  
◽  
Maria Esperidiao ◽  
Jaime Boaventura ◽  
Elizabete Lucas ◽  
...  
Keyword(s):  
Polymer Composites ◽  
Food Packaging ◽  
Low Cost ◽  
Condensation Reaction ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Swelling Capacity ◽  
Ft Ir

In this work, in order to obtain materials with potential for treatment of water from oil industry, polymer composites were synthesized by polymerization reaction via free radical using n-hydroxymethyl acrylamide (HMAA) in the presence of post-consumer polypropylene (PP) with subsequent condensation reaction catalyzed by heating, which avoids the use of crosslinking agents. The products were characterized by Fourier transform infrared spectroscopy (FT-IR), optical microscopy (OM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD). Moreover, the bulk density and the degree of swelling were also determined. The synthesis was shown to be reproducible and led to achieving polymer composites with high levels of PP after usage from food packaging, which can be associated with a relatively low cost of production. The swelling capacity and the thermal stability of the composite increased with increasing PP content in the mixture.

Polymerization and Characterization of Functionalized Poly(L-Lactide)

2009 ◽  
Vol 620-622 ◽  
pp. 595-598
Author(s):  
Yu Shun Jin ◽  
Fei Xiao ◽  
Wen Li Guo
Keyword(s):  
Ring Opening ◽  
Weight Percent ◽  
Molar Ratio ◽  
Polymerization Temperature ◽  
Scanning Calorimetry ◽  
1H Nuclear Magnetic Resonance ◽  
End Groups ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Functional poly(L-lactide) (PLLA-OH) containing vinyl groups as well as hydroxyl end groups was synthesized by ring-opening polymerization (ROP), using stannous octanoate as the catalyst and 2-hydroxyethyl methacrylate (HEMA) as the initiator. The structure of the obtained PLLA-OH was characterized using both Fourier Transform Infrared (FT-IR) spectroscopy and 1H nuclear magnetic resonance (1H-NMR) spectroscopy, while their crystallinities and thermo behavior were studied by differential scanning calorimetry (DSC), separately. The best condition for the ROP of the studied PLLA-OH was found with the polymerization temperature of T= 145 °C, the weight percent of the catalyst of 0.03 wt%, the ROP duration of 48 h and the L-lactide/initiator molar ratio of 100/1.

Thermal Behaviour of Candesartan Active substance and in pharmaceutical compounds

2017 ◽  
Vol 68 (8) ◽  
pp. 1895-1902
Author(s):  
Ioana Cristina Tita ◽  
Eleonora Marian ◽  
Bogdan Tita ◽  
Claudia Crina Toma ◽  
Laura Vicas
Keyword(s):  
Thermal Behaviour ◽  
Active Substance ◽  
Pharmaceutical Research ◽  
Pharmaceutical Product ◽  
Nitrogen Atmosphere ◽  
Pure Substance ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Ft Ir

Thermal analysis is one of the most frequently used instrumental techniques in the pharmaceutical research, for the thermal characterization of different materials from solids to semi-solids, which are of pharmaceutical relevance. In this paper, simultaneous thermogravimetry/derivative thermogravimetry (TG/DTG) and differential scanning calorimetry (DSC) were used for characterization of the thermal behaviour of candesartan cilexetil � active substance (C-AS) under dynamic nitrogen atmosphere and nonisothermal conditions, in comparison with pharmaceutical product containing the corresponding active substance. It was observed that the commercial samples showed a different thermal profile than the standard sample, caused by the presence of excipients in the pharmaceutical product and to possible interaction of these with the active substance. The Fourier transformed infrared spectroscopy (FT-IR) and X-ray powder diffraction (XRPD) were used as complementary techniques adequately implement and assist in interpretation of the thermal results. The main conclusion of this comparative study was that the TG/DTG and DSC curves, together with the FT-IR spectra, respectively X-ray difractograms constitute believe data for the discrimination between the pure substance and pharmaceutical forms.

Characterization of bi-layered magnetic nanoparticles synthesized via two-step surface-initiated ring-opening polymerization

2015 ◽  
Vol 87 (11-12) ◽  
pp. 1085-1097 ◽  
Author(s):  
Li Wang ◽  
Stefan Baudis ◽  
Karl Kratz ◽  
Andreas Lendlein
Keyword(s):  
Magnetic Nanoparticles ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Polymer Networks ◽  
Gel Permeation Chromatography ◽  
Degree Of Crystallinity ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Transmission Electron

AbstractA versatile strategy to integrate multiple functions in a polymer based material is the formation of polymer networks with defined nanostructures. Here, we present synthesis and comprehensive characterization of covalently surface functionalized magnetic nanoparticles (MNPs) comprising a bi-layer oligomeric shell, using Sn(Oct)2 as catalyst for a two-step functionalization. These hydroxy-terminated precursors for degradable magneto- and thermo-sensitive polymer networks were prepared via two subsequent surface-initiated ring-opening polymerizations (ROPs) with ω-pentadecalactone and ε-caprolactone. A two-step mass loss obtained in thermogravimetric analysis and two distinct melting transitions around 50 and 85°C observed in differential scanning calorimetry experiments, which are attributed to the melting of OPDL and OCL crystallites, confirmed a successful preparation of the modified MNPs. The oligomeric coating of the nanoparticles could be visualized by transmission electron microscopy. The investigation of degrafted oligomeric coatings by gel permeation chromatography and 1H-NMR spectroscopy showed an increase in number average molecular weight as well as the presence of signals related to both of oligo(ω-pentadecalactone) (OPDL) and oligo(ε-caprolactone) (OCL) after the second ROP. A more detailed analysis of the NMR results revealed that only a few ω-pentadecalactone repeating units are present in the degrafted oligomeric bi-layers, whereby a considerable degree of transesterification could be observed when OPDL was polymerized in the 2nd ROP step. These findings are supported by a low degree of crystallinity for OPDL in the degrafted oligomeric bi-layers obtained in wide angle X-ray scattering experiments. Based on these findings it can be concluded that Sn(Oct)2 was suitable as catalyst for the preparation of nanosized bi-layered coated MNP precursors by a two-step ROP.

scholarly journals THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES

2021 ◽  
Vol 23 (1) ◽  
pp. 16
Author(s):  
Vienna Saraswaty ◽  
Rossy Choerun Nissa ◽  
Bonita Firdiana ◽  
Akbar Hanif Dawam Abdullah
Keyword(s):  
Tensile Strength ◽  
Physicochemical Characterization ◽  
Face Mask ◽  
Physicochemical Characteristics ◽  
Scanning Calorimetry ◽  
Elongation At Break ◽  
Ft Ir ◽  
The Government ◽  
Plastic Pellets

THE PHYSICOCHEMICAL CHARACTERISTICS OF RECYCLED-PLASTIC PELLETS OBTAINED FROM DISPOSABLE FACE MASK WASTES. The government policy to wear a face mask during the COVID-19 pandemic has increased disposable face mask wastes. Thus, to reduce such wastes, it is necessary to evaluate the physicochemical characteristics of disposable face masks wastes before the recycling process and the recycled products. In this study, physicochemical characterization of the 3-ply disposable face masks and the recycled plastic pellets after disinfection using 0.5% v/v sodium hypochlorite were evaluated. A set of parameters including the characterization of surface morphology by a scanning electron microscope (SEM), functional groups properties by a fourier transform infra-red spectroscopy (FT-IR), thermal behavior by a differential scanning calorimetry (DSC), tensile strength and elongation at break were evaluated. The surface morphological of each layer 3-ply disposable face mask showed that the layers were composed of non-woven fibers. The FT-IR evaluation revealed that 3-ply disposable face mask was made from a polypropylene. At the same time, the DSC analysis found that the polypropylene was in the form of homopolymer. The SEM analysis showed that the recycled plastic pellets showed a rough and uneven surface. The FT-IR, tensile strength and elongation at break of the recycled plastic pellets showed similarity with a virgin PP type CP442XP and a recycled PP from secondary recycling PP (COPLAST COMPANY). In summary, recycling 3-ply disposable face mask wastes to become plastic pellets is recommended for handling disposable face mask wastes problem.

scholarly journals GREEN SYNTHESIS AND SPECTROSCOPIC CHARACTERIZATION OF IRON (III) COMPLEX OF UREA FROM HUMAN URINE AND IRON RUST

2020 ◽  
Vol 45 (5) ◽  
Author(s):  
V.O. Uduah ◽  
J.J. Gongden ◽  
M.L. Kagoro ◽  
K.K. Gurumyen ◽  
Y.N. Lohdip ◽  
...  
Keyword(s):  
Human Urine ◽  
Synthesis Method ◽  
Reaction Medium ◽  
Spectroscopic Characterization ◽  
Waste Materials ◽  
Spectroscopic Techniques ◽  
Distilled Water ◽  
Oxide Composition ◽  
Ft Ir

This work presents a dry synthesis of Iron (III) complex with urea isolated from human urine and Fe (III) obtained from iron rust particles. Iron (III), PI (Purified iron rust), was isolated from iron rust in 10% hydrochloric acid, HCl and distilled water respectively. The complex was synthesized via dry-synthesis method using the melted urea as reaction medium. The isolated Fe (III) was characterized by elemental analysis which was done using XRF Cu-Zn method. The complex was prepared in a 1:4 metal to ligand (M-L) ratio. The stoichiometry of reaction indicate a 1:3 ratio of M-L (Fe-U). The complex was characterized by FT-IR, UV-vis, XRF and XRD spectroscopic techniques. The Fe (III) isolate and Fe-U complex shows percentage yields of 35.7% and ~92% respectively. The elemental and oxide composition of Fe and Fe2O3 (i.e., PI) were 40.387% and 57.753% respectively. The results obtained from the characterization of the iron-urea complex, IUC, indicate FT-IR result as symmetric and asymmetric frequencies with peaks of a combination band of Vs (NH) and Vas (NH), C=O and V (C-N) all stretched, XRD showed the crystal to be amorphous. The elemental and oxide composition of the Fe and Fe2O3 in IUC were 40.007 and 44.201 respectively. The results obtained revealed that useful complexes can be synthesized easily from waste materials, such as urine and iron rust particles, which complement Green chemistry.

Preparation and characterization of oxidized starch-graft-poly(styrene-butyl acrylate) latex via emulsion polymerization

2014 ◽  
Vol 34 (7) ◽  
pp. 611-616 ◽  
Author(s):  
Shijie Cheng ◽  
Jun Xu ◽  
Yumin Wu
Keyword(s):  
Emulsion Polymerization ◽  
Butyl Acrylate ◽  
Colloidal Stability ◽  
Graft Copolymerization ◽  
Scanning Calorimetry ◽  
Oxidized Starch ◽  
Ir Transmission ◽  
Ft Ir ◽  
Synthetic Latex

Abstract Oxidized starch-graft-poly(styrene-butyl acrylate) [OS-g-P(St-BA)] latex was synthesized by the graft copolymerization of OS with St and n-butyl acrylate (BA) via emulsion polymerization. The graft copolymers were characterized by Fourier transform infrared (FT-IR), transmission electronic microscopy (TEM), dynamic light scattering, thermogravimetry (TG), and differential scanning calorimetry (DSC). The effects of the amount of OS, monomers, and initiator on graft copolymerization were investigated. Under the optimal conditions, the percentage of graft (PG), grafting efficiency (GE), and ζ potential could reach 256.5%, 41.7%, and -30.1 mV, respectively. The results indicated that the OS grafted onto particles greatly enhanced the colloidal stability of latex. The thermal stability properties of OS-g-P(St-BA) were also improved by the addition of OS. The OS-g-P(St-BA) latex may be used to partly replace the conventional synthetic latex for paper coating.

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