scholarly journals Lipase mediated synthesis of polycaprolactone and its silica nanohybrid

2019 ◽  
Vol 91 (6) ◽  
pp. 957-965
Author(s):  
Meltem Akkulak ◽  
Yasemin Kaptan ◽  
Yasar Andelib Aydin ◽  
Yuksel Avcibasi Guvenilir
Keyword(s):  
Average Molecular Weight ◽  
Proton Nuclear Magnetic Resonance ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Structural Investigations ◽  
Crystallinity Degree ◽  
Molecular Weights ◽  
H Nmr

Abstract In this study, rice husk ash (RHA) silanized with 3-glycidyloxypropyl trimethoxysilane was used as support material to immobilize Candida antarctica lipase B. The developed biocatalyst was then utilized in the ring opening polymerization (ROP) of ε-caprolactone and in situ development of PCL/Silica nanohybrid. The silanization degree of RHA was determined as 4 % (w) by thermal gravimetric analysis (TGA). Structural investigations and calculation of molecular weights of nanohybrids were realized by proton nuclear magnetic resonance (1H NMR). Crystallinity was determined by differential scanning calorimetry (DSC) and X-ray diffraction (XRD). Scanning Electron Microscopy (SEM) was used for morphological observations. Accordingly, the PCL composition in the nanohybrid was determined as 4 %, approximately. Short chained amorphous PCL was synthesized with a number average molecular weight of 4400 g/mol and crystallinity degree of 23 %. In regards to these properties, synthesized PCL/RHA composite can find use biomedical applications.

Halogenated sunflower oil as a precursor for synthesis of polysulfide polymer

e-Polymers ◽  
2016 ◽  
Vol 16 (1) ◽  
pp. 33-39 ◽  
Author(s):  
Samira Moqadam ◽  
Mehdi Salami-Kalajahi
Keyword(s):  
Sunflower Oil ◽  
Proton Nuclear Magnetic Resonance ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir ◽  
Harsh Conditions ◽  
Thermal Stability Of ◽  
Polysulfide Polymer

AbstractPolysulfide polymers usually are prepared by the reaction of different dihalide compounds with disodium polysulfides. In this field, dihalides are expensive and produced from halogenation of organic compounds by different methods with harsh conditions. To overcome this problem, in this work, sunflower oil as polyunsaturated oil was used as precursor to produce polyhalide compound. In this field, double bonds of oil were applied as functional groups to halogenate the sunflower via benzoyl peroxide-catalyzed reaction with hydrochloric acid. Also, Na2S3 was synthesized via the reaction between sulfur and sodium hydroxide. Then, halogenated oil was reacted with Na2S3 to produce sunflower oil-based polysulfide polymer. Fourier transform infrared spectroscopy (FT-IR) and proton nuclear magnetic resonance (1H NMR) were used to characterize the structure of sunflower oil and synthesized polysulfide polymer. The content of halogenation was also obtained via energy-dispersive X-ray spectroscopy (EDX). Thermal stability of synthesized polymer was determined by means of thermal gravimetric analysis (TGA) and glass transition temperature was investigated by differential scanning calorimetry (DSC).

Novel surface treatment for natural fiber composites

2017 ◽  
Vol 31 (16-19) ◽  
pp. 1744092 ◽  
Author(s):  
Wendy Zhang ◽  
Xiaowen Yuan
Keyword(s):  
Ring Opening ◽  
Natural Fiber ◽  
Fiber Composites ◽  
Proton Nuclear Magnetic Resonance ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Dsc Studies ◽  
Flax Fibers ◽  
H Nmr

Poly(lactide) (PLA) — flax fibers stereocomplex composites were prepared by casting commercial poly(L-lactide) (PLA) and flax-g-poly(D-lactide) (flax-g-PDLA), where flax-g-PDLA was synthesized via ring-opening polymerization. Successful surface grafting was revealed by Proton Nuclear Magnetic Resonance (1H NMR) spectroscopy, wide angle X-ray diffraction (WAXD) and differential scanning calorimetry (DSC) studies. DSC results showed that stereocomplex crystallites formed between the PLA matrix and flax-g-PDLA, resulting in good fiber/PLA interfacial adhesion.

scholarly journals Facile Synthesis, Characterization, and In Vitro Antimicrobial and Anticancer Activities of Biscoumarin Copolyester Bearing Pendant 3-(Trifluoromethyl)Styrene

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Narendran Kandaswamy ◽  
Nanthini Raveendiran
Keyword(s):  
Gel Permeation Chromatography ◽  
Inherent Viscosity ◽  
Proton Nuclear Magnetic Resonance ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Anticancer Activities ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Agar Disc

Synthesis of random biscoumarin copolyester bearing pendant 3-(trifluoromethyl)styrene was prepared by the reaction of biscoumarin monomer 3 and hydroquinone 5 with azeloyl chloride. The influence of pendant 3-(trifluoromethyl)styrene unit on the properties of copolyester such as inherent viscosity, solubility, and thermal stability was investigated and compared in detail. The inherent viscosity and polydispersity index of the copolyester were found to be 0.15 dL/g and 1.36, respectively. The chemical structure of the copolyester was investigated by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The physical properties of copolyester were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and X-ray diffraction (XRD) technique. Agar disc diffusion method was employed to study the antimicrobial activity of the random copolyester. In vitro anticancer activity against lung cancer (Hep-2) cell line was also investigated.

Synthesis and application of functionalized ionic liquids as solvent to corn stalk for phenolic resin modification

e-Polymers ◽  
2015 ◽  
Vol 15 (3) ◽  
pp. 195-201 ◽  
Author(s):  
Liying Guo ◽  
Bin Zhang ◽  
Shiyang Bai ◽  
Xiuyun Ma ◽  
Zhiming Wang
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquids ◽  
Phenolic Resin ◽  
Corn Stalk ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
H Nmr ◽  
Good Solubility

AbstractThree functionalized ionic liquids (ILs) of [HeMIM]Cl, [CeMIM]Cl, and [AeMIM]Br that can dissolve corn stalk were synthesized and characterized via Fourier transform infrared spectroscopy (FTIR) and 1H NMR. The dissolved corn stalk was in situ blended with phenol and formaldehyde to produce modified phenolic resin composites. The resulting composites were characterized via FTIR, differential scanning calorimetry, and X-ray diffraction analysis, and tested for their mechanical properties. In addition, the effects of ILs on the dissolution rate of corn stalks and on the mechanical properties of the modified phenolic resin were investigated as well. The results showed that the synthesized ILs presented good solubility toward corn stalk at the optimum temperature of 90°C. After modification with corn stalk dissolved in ILs, the mechanical properties of phenolic resin were significantly improved. At the same conditions, the phenolic resin modified with [AeMIM]Br presented the lowest concentration of free formaldehyde and the best mechanical properties, in which the tensile strength and impact strength were improved from 3.28 MPa and 0.93 kJ/m2 to 9.36 MPa and 5.74 kJ/m2, respectively, but the hardness only changed slightly.

Preparation of Organic/Inorganic Nanocomposites with Microwave Process

2006 ◽  
Vol 317-318 ◽  
pp. 669-672 ◽  
Author(s):  
D.H. Kim ◽  
Seong Soo Park ◽  
B.S. Jun ◽  
Jong Kook Lee ◽  
Kyu Hong Hwang ◽  
...  
Keyword(s):  
In Situ Polymerization ◽  
Layered Silicate ◽  
Clay Content ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Transmission Electron ◽  
Inorganic Nanocomposites ◽  
Microwave Process

Polymer/layered silicate nanocomposities were prepared by in situ polymerization with microwave process. The influence of the amount of clay on the structure and thermal properties for the synthesized nanocomposites were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA). It was found that the structure of nanocomposites, an intercalated/exfoliated structure, depended on the clay content.

scholarly journals Synthesis, Characterization, and In Vitro Antimicrobial and Anticancer Evaluation of Copolyester Bearing 4-Arylidene Curcumin in the Main Chain

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Narendran Kandaswamy ◽  
Nanthini Raveendiran
Keyword(s):  
Gel Permeation Chromatography ◽  
Inherent Viscosity ◽  
Proton Nuclear Magnetic Resonance ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Polymer Backbone ◽  
H Nmr ◽  
Agar Disc

Synthesis of random copolyester bearing 4-arylidene curcumin M1 in the polymer backbone was prepared by solution polycondensation method. The influence of copolyester bearing 4-arylidene curcumin M1 unit on the properties of copolyester such as inherent viscosity, solubility, and thermal stability was investigated and studied in detail. The inherent viscosity and polydispersity index of the copolyester were found to be 0.19 dL/g and 1.38, respectively. The chemical structure of the copolyester was investigated by Fourier-transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H-NMR) spectroscopy. The physical properties of copolyester were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation chromatography (GPC), and X-ray diffraction (XRD) technique. Agar disc diffusion method was employed to study the antimicrobial activity of the random copolyester. In vitro anticancer activity against lung cancer (Hep-2) cell line was investigated.

Formation mechanism of spinel LiTi2O4 prepared by carbon thermal reduction reaction

RSC Advances ◽  
2015 ◽  
Vol 5 (118) ◽  
pp. 97720-97723 ◽  
Author(s):  
Guijun Yang ◽  
Jianwen Yang ◽  
Lingzhi Zhang
Keyword(s):  
Formation Mechanism ◽  
Variable Temperature ◽  
Thermal Reduction ◽  
Reduction Reaction ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
System P

The formation mechanism of LiTi2O4 is investigated by in situ variable temperature X-ray diffraction and thermal gravimetric analysis/differential scanning calorimetry system.

In-situ stabilization of silver nanoparticles in polymer hydrogels for enhanced catalytic reduction of macro and micro pollutants

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Luqman Ali Shah ◽  
Rida Javed ◽  
Mohammad Siddiq ◽  
Iram BiBi ◽  
Ishrat Jamil ◽  
...  
Keyword(s):  
Catalytic Reduction ◽  
Thermo Gravimetric Analysis ◽  
Activation Parameters ◽  
Reduction Reaction ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
In Situ Stabilization ◽  
Hybrid Hydrogels ◽  
Kinetics Of

AbstractThe in-situ stabilization of Ag nanoparticles is carried out by the use of reducing agent and synthesized three different types of hydrogen (anionic, cationic, and neutral) template. The morphology, constitution and thermal stability of the synthesized pure and Ag-entrapped hybrid hydrogels were efficiently confirmed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and thermo gravimetric analysis (TGA). The prepared hybrid hydrogels were used in the decolorization of methylene blue (MB) and azo dyes congo red (CR), methyl Orange (MO), and reduction of 4-nitrophenol (4-NP) and nitrobenzene (NB) by an electron donor NaBH4. The kinetics of the reduction reaction was also assessed to determine the activation parameters. The hybrid hydrogen catalysts were recovered by filtration and used continuously up to six times with 98% conversion of pollutants without substantial loss in catalytic activity. It was observed that these types of hydrogel systems can be used for the conversion of pollutants from waste water into useful products.

Synthesis and properties of a benzoxazine monomer containing maleimide and biphenyl groups

2021 ◽  
pp. 095400832199674
Author(s):  
Tao Guo ◽  
Yang Fan ◽  
Chang Bo ◽  
Zhang Qi ◽  
Han Tao ◽  
...  
Keyword(s):  
Weight Loss ◽  
Loss Rate ◽  
Proton Nuclear Magnetic Resonance ◽  
Significant Weight Loss ◽  
Scanning Calorimetry ◽  
Weight Loss Rate ◽  
Reaction Heat ◽  
H Nmr ◽  
Curing Reaction ◽  
Dsc Curves

Benzoxazine resin exhibits excellent properties and is widely used in many fields. Herein, the synthesis of a novel compound, the bis(2,4-dihydro-2 H-3-(4- N-maleimido)phenyl-1,3-benzoxazinyl)biphenyl (BMIPBB), has been reported, which was synthesized by reacting N-(4-aminophenyl)maleimide (APMI), formaldehyde, and 4,4’-dihydroxybiphenyl. 1,3,5-three(4-(maleimido)phenyl)-1,3,5-triazine (TMIPT) was formed as an intermediate during the reaction. The proton nuclear magnetic resonance (1H-NMR) and Fourier transform-infrared (FTIR) spectroscopy experiments were conducted to determine the structure of BMIPBB. BMIPBB was obtained as a reddish-brown solid in 40.1% yield. The thermal properties of BMIPBB were investigated using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) techniques. Analysis of the DSC curves revealed that the broad peak representing the release of curing reaction heat appeared in the temperature range of 140–330°C. The peak temperature was 242.59°C and the heat of the reaction was 393.82 J/g, indicating that the rate of the curing reaction was low and the heat of the reaction was high. Analysis of the TGA results revealed that the weight loss rate was 5% at 110°C. The monomer exhibited a significant weight loss in the range of 320–500°C. The compound lost 50% of its weight at a temperature of 427°C.

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

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