scholarly journals Synergistic interaction of renewable nipagin and eugenol for aromatic copoly(ether ester) materials with desired performance

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao

AbstractNaturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) polymers. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11−xE1x and PHN11−xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability, high boiling point, and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggested that properties of this kind of poly(ether ester)s could be finely tuned by the relative content of two components for the desired applications (elastomer, rubbery) suitable for different scenarios from polyethylene glycol terephthalate (PET) and polybutylene terephthalate (PBT).

2021 ◽  
Author(s):  
Keling Hu ◽  
Huachao Sui ◽  
Dongping Zhao

Abstract Naturally occurring nipagin and eugenol were used as the collaborative starting materials for poly(ether ester) materials. In this study, two series of nipagin and eugenol-derived copoly(ether ester)s, PHN11-xE1x and PHN11-xE2x (x = 0%, 5%, 10%, 15%, 20%), were prepared with renewable 1,6-hexanediol as a comonomer. The nipagin-derived component acts as the renewable surrogate of petroleum-based dimethyl terephthalate (DMT), while the eugenol-derived component acts as the cooperative property modifier of parent homopoly(ether ester) PHN1. 1,6-Hexanediol was chosen as the spacer because of its renewability and short chain to enhance the glass transition temperatures (Tgs) of materials. The molecular weights and chemical structures were confirmed by gel permeation chromatograph (GPC), NMR and FTIR spectroscopies. Thermal and crystalline properties were studied by thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC) and wide-angle X-ray diffraction (WXRD). The tensile assays were conducted to evaluate the mechanical properties. The results suggest that properties of such kind of poly(ether ester)s can be finely tuned by the relative content of two components. Synergistic interaction of two structurally distinctive parts endows the materials with high performance.


2019 ◽  
Vol 31 (5) ◽  
pp. 580-589 ◽  
Author(s):  
Wei Wang ◽  
Guofei Chen ◽  
Xingzhong Fang

Most of the existing polyimide oligomers for resin transfer molding (RTM) processing exhibited high melt viscosity, which can only maintain below 1 Pa·s at 280°C for 2 h, leading to very high process temperatures. So novel RTM-type oligomers with lower and stable melt viscosities are more desirable. Three series of thermoset oligoimides derived from 1,4-bis(3,4-dicarboxy phenoxy)benzene dianhydride and three different aromatic diamines were prepared herein. The diamines included 4,4′-oxydianiline, 2,2′-bis(trifluoromethyl)benzidine (TFDB), and 2-phenyl-4,4′-diaminodiphenyl ether ( p-ODA). 4-Phenylethynylphthalic anhydride was used as an endcapping reagent. Effects of the chemical structures and molecular weights of the oligoimides on their aggregated structures, melt processability, and the thermal and mechanical properties of the cured films were then systematically investigated. X-Ray diffraction results indicated that ODA series oligoimides and TFDB series oligoimides showed crystallinity in various degrees. However, the asymmetric p-ODA enables the p-ODA series oligoimides to exhibit amorphous forms. It was found that the p-ODA-based oligoimide with a molecular weight of 750 g mol−1 showed very low melt viscosity of 1 Pa·s even at 210°C, and the melt viscosity could maintain below 1 Pa·s after isothermal aging for 2 h at any temperature in the range of 200–280°C by rheological measurements. The cured film also showed a high glass transition temperature of 355°C by dynamic mechanical analysis, very good thermal stability by thermogravimetric analysis, and good mechanical properties. It might be more suitable for RTM processes in the future.


2014 ◽  
Vol 1004-1005 ◽  
pp. 409-414 ◽  
Author(s):  
Shuai Yong Jin ◽  
Kang Kang Guo ◽  
Hui Min Qi ◽  
Ya Ping Zhu ◽  
Fan Wang

The processible and high yield polyborosilazane (PBSZ) precursor for SiBN ceramics was prepared by coammonolysis reaction of dichlorosilane and trichloroborazine. The synthesized PBSZ precursor was characterized by Fourier Transform Infrared spectroscopy (FTIR),1H,11B, and29Si Nuclear Magnetic Resonance (NMR), and its ceramic conversion chemistry was investigated by differential scanning calorimetric (DSC), X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and thermal gravimetric analysis (TGA). The PBSZ precursor is a viscous liquid and changes to an insoluble solid via a cross-linking reaction between the N-H group and Si-H group as post-heated from 60 to 180°C. The insoluble solid is transformed to Si3N4and BN amorphous structures with an approximately 95% ceramic yield after being pyrolyzed to 1000°C.


Author(s):  
W. W. Barker ◽  
W. E. Rigsby ◽  
V. J. Hurst ◽  
W. J. Humphreys

Experimental clay mineral-organic molecule complexes long have been known and some of them have been extensively studied by X-ray diffraction methods. The organic molecules are adsorbed onto the surfaces of the clay minerals, or intercalated between the silicate layers. Natural organo-clays also are widely recognized but generally have not been well characterized. Widely used techniques for clay mineral identification involve treatment of the sample with H2 O2 or other oxidant to destroy any associated organics. This generally simplifies and intensifies the XRD pattern of the clay residue, but helps little with the characterization of the original organoclay. Adequate techniques for the direct observation of synthetic and naturally occurring organoclays are yet to be developed.


Processes ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 1238
Author(s):  
Garven M. Huntley ◽  
Rudy L. Luck ◽  
Michael E. Mullins ◽  
Nick K. Newberry

Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m2/g and NV-Na 19.0(4) to 158(7) m2/g. 29Si and 27Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K+ ion pretreatment in the HCl modified zeolites.


Marine Drugs ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 35
Author(s):  
Mohamed Shaaban ◽  
Ghada S. E. Abou-El-Wafa ◽  
Christopher Golz ◽  
Hartmut Laatsch

Analysis of the air-dried marine red alga Laurencia papillosa, collected near Ras-Bakr at the Suez gulf (Red Sea) in Egypt delivered five new halogenated terpene derivatives: aplysiolic acid (1), 7-acetyl-aplysiol (2), aplysiol-7-one (3), 11,14-dihydroaplysia-5,11,14,15-tetrol (5a), and a new maneonene derivative 6, named 5-epi-maneolactone. The chemical structures of these metabolites were characterized employing spectroscopic methods, and the relative and absolute configurations were determined by comparison of experimental and ab initio-calculated NMR, NOE, ECD, and ORD data, and by X-ray diffraction of 2 and 6. The antimicrobial activities of the crude extract and compounds 1–3, 5a and 6 were studied.


BMC Chemistry ◽  
2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Arefeh Dehghani Tafti ◽  
Bi Bi Fatemeh Mirjalili ◽  
Abdolhamid Bamoniri ◽  
Naeimeh Salehi

AbstractNano-eggshell/Ti(IV) as a novel naturally based catalyst was prepared, characterized and applied for the synthesis of dihydropyrano[2,3-c]pyrazole derivatives. The characterization of nano-eggshell/Ti(IV) was performed using Fourier Transform Infrared spectroscopy, X-ray Diffraction, Field Emission Scanning Electron Microscopy, Energy-Dispersive X-ray Spectroscopy, and Thermo Gravimetric Analysis. Dihydropyrano[2,3-c]pyrazoles were synthesized in the presence of nano-eggshell/Ti(IV) via a four component reaction of aldehydes, ethyl acetoacetate, malononitrile and hydrazine hydrate at room temperature under solvent free conditions. The principal affairs of this procedure are mild condition, short reaction times, easy work-up, high yields, reusability of the catalyst and the absence of toxic organic solvents.


Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1712
Author(s):  
Appusamy Muthukrishnaraj ◽  
Salma Ahmed Al-Zahrani ◽  
Ahmed Al Otaibi ◽  
Semmedu Selvaraj Kalaivani ◽  
Ayyar Manikandan ◽  
...  

Towards the utilization of Cu2O nanomaterial for the degradation of industrial dye pollutants such as methylene blue and methyl orange, the graphene-incorporated Cu2O nanocomposites (GCC) were developed via a precipitation method. Using Hummers method, the grapheme oxide (GO) was initially synthesized. The varying weight percentages (1–4 wt %) of GO was incorporated along with the precipitation of Cu2O catalyst. Various characterization techniques such as Fourier-transform infra-red (FT-IR), X-ray diffraction (XRD), UV–visible diffused reflectance (UV-DRS), Raman spectroscopy, thermo gravimetric analysis (TGA), energy-dispersive X-ray analysis (EDX), and electro chemical impedance (EIS) were followed for characterization. The cabbage-like morphology of the developed Cu2O and its composites were ascertained from field-emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HR-TEM). In addition, the growth mechanism was also proposed. The results infer that 2 wt % GO-incorporated Cu2O composites shows the highest value of degradation efficiency (97.9% and 96.1%) for MB and MO at 160 and 220 min, respectively. Further, its catalytic performance over visible region (red shift) was also enhanced to an appreciable extent, when compared with that of other samples.


1992 ◽  
Vol 45 (12) ◽  
pp. 2089 ◽  
Author(s):  
EL Ghisalberti ◽  
BW Skelton ◽  
AH White

The structure of the compound obtained on heating the naturally occurring clerodane furanoditerpene (1) had been formulated as (2) on the basis of spectroscopic studies. A single-crystal X-ray diffraction study on the dihydro derivative of (2) has confirmed this and provides support for the stereochemistry previously assigned to (1) on the basis of chemical evidence.


2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.


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