scholarly journals Regular Polymeric Microspheres with Highly Developed Internal Structure and Remarkable Thermal Stability

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2240
Author(s):  
Małgorzata Maciejewska ◽  
Barbara Gawdzik ◽  
Magdalena Rogulska
Keyword(s):  
Thermal Stability ◽  
Internal Structure ◽  
Suspension Polymerization ◽  
Nitrogen Adsorption ◽  
Distribution Analysis ◽  
Scanning Calorimetry ◽  
Polymeric Microspheres ◽  
Functional Monomers ◽  
Good Thermal Stability ◽  
Adsorption Desorption

In this study, the synthesis and characterization of permanently porous polymeric microspheres was presented. The microspheres were obtained via suspension polymerization using diverse functional monomers, such as 4,4′-bis(methacryloyloxymethylphenyl)sulphone, 1,4-bis(methacryloyloxymethyl)benzene, 4,4′-bis(methacryloyloxymethylphenyl)methane, N-vinylpyrrolidone, ethylene glycol dimethacrylate, and divinylbenzene as a co-monomer. As porogenic solvents, toluene and chlorobenzene were applied. The main aim of the research was to synthesize polymers having a highly developed internal structure and a good thermal stability. The synthesized materials were characterized by ATR-FTIR, scanning electron microscopy, a size distribution analysis, a low-temperature nitrogen adsorption–desorption method, differential scanning calorimetry, and thermogravimetry coupled with FTIR and inverse gas chromatography. It was found that, depending on the functional monomer, regular microspheres with a specific surface area in the range of 418–746 m2/g can be successfully synthesized. Moreover, all the synthesized copolymers showed a good thermal stability. In helium, they exhibited 5% mass losses at temperatures over 300 °C, whereas in air these values were only slightly lower. In addition, the presence of miscellaneous functional groups promoted diverse kinds of interactions. Therefore, the microspheres can be possibly use in many adsorption techniques including high temperature processes.

scholarly journals Silver nanoparticles deposited on pyrogenic silica solids: Preparation and textural properties

2017 ◽  
Vol 35 (7-8) ◽  
pp. 714-720 ◽  
Author(s):  
M Zienkiewicz-Strzałka ◽  
M Błachnio ◽  
A Deryło-Marczewska ◽  
RB Kozakevych ◽  
YM Bolbukh ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silicon Dioxide ◽  
Noble Metal ◽  
Materials Science ◽  
Textural Properties ◽  
Nitrogen Adsorption ◽  
Nanostructured Material ◽  
Scanning Calorimetry ◽  
Adsorption Desorption ◽  
Pyrogenic Silicon Dioxide

Silver-based nanomaterials and composites are important components in materials science and engineering due to the reactivity of silver nanophase based on exceptional surface effects. Ag-doped SiO2 nanocomposites were synthesized by wet impregnation procedure of aminopropyl-functionalized silica materials with submicrometer structure. Aminopropyl-functionalized pyrogenic silicon dioxide with amount of amino groups established as half and close to full monolayer was used to immobilize the nanosilver phase obtained from ammoniacal silver complex as a noble metal precursor. Pyrogenic silicon dioxide as an inexpensive nanostructured material with useful properties including adsorptive affinity for noble metal ions and organic macromolecules was applied as a support for diamminesilver(I) ions and finally for silver nanoparticles. In the present study, the effect of amino-functionalization and silver nanoparticles deposition was monitored by investigation of the textural properties and thermal stability of obtained nanocomposites. The properties of the nanocomposites were investigated by transmission electron microscopy, nitrogen adsorption–desorption isotherms, and thermal analysis (thermogravimetry/differential scanning calorimetry).

scholarly journals Electrospun Silk-Boron Nitride Nanofibers with Tunable Structure and Properties

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1093
Author(s):  
Ye Xue ◽  
Xiao Hu
Keyword(s):  
Thermal Stability ◽  
Boron Nitride ◽  
Hexagonal Boron Nitride ◽  
Environmental Research ◽  
Strong Interactions ◽  
Helical Structures ◽  
Scanning Calorimetry ◽  
Modulated Differential Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Thermal Stability Of

In this study, hexagonal boron nitride (h-BN) nanosheets and Bombyx mori silk fibroin (SF) proteins were combined and electrospun into BNSF nanofibers with different ratios. It was found that the surface morphology and crosslinking density of the nanofibers can be tuned through the mixing ratios. Fourier transform infrared spectroscopy study showed that pure SF electrospun fibers were dominated by random coils and they gradually became α-helical structures with increasing h-BN nanosheet content, which indicates that the structure of the nanofiber material is tunable. Thermal stability of electrospun BNSF nanofibers were largely improved by the good thermal stability of BN, and the strong interactions between BN and SF molecules were revealed by temperature modulated differential scanning calorimetry (TMDSC). With the addition of BN, the boundary water content also decreased, which may be due to the high hydrophobicity of BN. These results indicate that silk-based BN composite nanofibers can be potentially used in biomedical fields or green environmental research.

scholarly journals Thermal characterization of novel aliphatic polyesters with ether and thioether linkages

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Soccio ◽  
N. Lotti ◽  
L. Finelli ◽  
A. Munari
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Chemical Structure ◽  
Room Temperature ◽  
Crystallization Rate ◽  
Thermal Characterization ◽  
Scanning Calorimetry ◽  
Aliphatic Polyesters ◽  
Good Thermal Stability

AbstractSeveral novel ether or thioether linkage containing aliphatic polyesters and poly(alkylene dicarboxylate)s were synthesized for comparison and characterized in terms of chemical structure and molecular weight. The thermal behavior was examined by thermogravimetric analysis and differential scanning calorimetry. All the polymers showed a good thermal stability, even though lower for the ether or thioether linkage-containing polyesters. The decrement of the thermal stability appears to be more relevant in the case of the presence of sulphur atoms. At room temperature the samples appeared semicrystalline, except PTTDG and PDEDG, which were viscous oils; the effect of the introduction of ether or thioether group was an increment of the Tgvalue, a decrement of the melting temperature and a significant decrease of the crystallization rate. The entity of the variations was found to be affected by the kind of group introduced, and the trend observed can be explained on the basis of atom electronegativity and dimensions

Heat-resistant and photoluminescent indole-based poly(ether sulfone)s

2017 ◽  
Vol 30 (4) ◽  
pp. 475-479 ◽  
Author(s):  
Wenxuan Wei ◽  
Li Yang ◽  
Guanjun Chang
Keyword(s):  
Thermal Stability ◽  
High Performance ◽  
Proton Nuclear Magnetic Resonance ◽  
Resonance Spectroscopy ◽  
Condensation Polymerization ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
High Performance Polymers ◽  
Good Agreement

Indole-based poly(ether sulfone)s (PINESs), as novel high-performance polymers, have been obtained by the condensation polymerization of 4-hydroxyindole and hydroquinone with activated difluoro monomers via a catalyst-free nucleophilic substitution reaction. The structures of the polymers are characterized by means of Fourier transform infrared and proton nuclear magnetic resonance spectroscopy, and the results show good agreement with the proposed structures. Differential scanning calorimetry and thermogravimetric analysis measurements exhibit that polymers possess high glass transition temperature ( Tgs > 245°C) and good thermal stability with high decomposition temperatures ( Tds > 440°C). In addition, due to their special structure, PINESs are endowed with significantly strong photonic luminescence in N, N-dimethylformamide.

scholarly journals Photocatalytic and adsorption properties of TiO2-pillared montmorillonite obtained by hydrothermally activated intercalation of titanium polyhydroxo complexes

2018 ◽  
Vol 9 ◽  
pp. 364-378 ◽  
Author(s):  
Mikhail F Butman ◽  
Nikolay L Ovchinnikov ◽  
Nikita S Karasev ◽  
Nataliya E Kochkina ◽  
Alexander V Agafonov ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Nitrogen Adsorption ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
New Approach ◽  
Pillared Montmorillonite ◽  
Degussa P25 ◽  
Adsorption Desorption ◽  
High Degree

We report on a new approach for the synthesis of TiO2-pillared montmorillonite, where the pillars exhibit a high degree of crystallinity (nanocrystals) representing a mixture of anatase and rutile phases. The structures exhibit improved adsorption and photocatalytic activity as a result of hydrothermally activated intercalation of titanium polyhydroxo complexes (i.e., TiCl4 hydrolysis products) in a solution with a concentration close to the sol formation limit. The materials, produced at various annealing temperatures from the intercalated samples, were characterized by infrared spectroscopy, differential scanning calorimetry (DSC)/thermogravimetric analysis (TGA), X-ray diffraction, dynamic light scattering (DLS) measurements, and liquefied nitrogen adsorption/desorption. The photocatalytic activity of the TiO2-pillared materials was studied using the degradation of anionic (methyl orange, MO) and cationic (rhodamine B, RhB) dyes in water under UV irradiation. The combined effect of adsorption and photocatalysis resulted in removal of 100% MO and 97.5% RhB (with an initial concentration of 40 mg/L and a photocatalyst-sorbent concentration of 1 g/L) in about 100 minutes. The produced TiO2-pillared montmorillonite showed increased photocatalytic activity as compared to the commercially available photocatalyst Degussa P25.

Novel polyimides based on diamine containing thiazole units with thioether linkage and pyridine as pendent group

2017 ◽  
Vol 30 (7) ◽  
pp. 840-846 ◽  
Author(s):  
Jafar Rezania ◽  
Abbas Shockravi ◽  
Morteza Ehsani ◽  
Vahid Vatanpour
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Pyridine Ring ◽  
Polar Solvent ◽  
Nitrogen Atmosphere ◽  
Scanning Calorimetry ◽  
Glass Transition Temperatures ◽  
Good Thermal Stability ◽  
Pendent Group ◽  
High Yields

Three new organic-soluble polyimides (PIs) bearing flexible thioether linkages, thiazole, and pyridine ring units were synthesized from a novel thioether-bridged diamine monomer and commercially available aromatic dianhydrides (1–3) via chemical imidization method. The resulting polymers were obtained in high yields and possessed inherent viscosities in the range of 0.67–0.89. The PIs are characterized by Fourier-transform infrared (FTIR), nuclear magnetic resonance (NMR), differential scanning calorimetry, and thermogravimetric analysis (TGA). All of the PIs exhibited excellent solubility in polar solvent. The polymers showed good thermal stability with glass transition temperatures ( Tgs) in the range of 194–244°C, and decomposition temperatures ( T5%) exceeding 300°C were observed using TGA in nitrogen atmosphere for the current polymers.

Thermal properties of a series of tetrafunctional fluorene-based oxazines/P-a blends

2016 ◽  
Vol 29 (10) ◽  
pp. 1139-1147 ◽  
Author(s):  
Zi Sang ◽  
Tiantian Feng ◽  
Wenbin Liu ◽  
Jun Wang ◽  
Mehdi Derradji
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Mechanical Analysis ◽  
Proton Nuclear Magnetic Resonance ◽  
Primary Amines ◽  
Resonance Spectroscopy ◽  
High Glass Transition Temperature ◽  
Scanning Calorimetry ◽  
Good Thermal Stability

A new series of aniline and aniline-mixed tetrafunctional fluorene-based oxazine monomers were synthesized using 2,7-hydroxy-9,9-bis-(4-hydroxyphenyl) fluorene, paraformaldehyde, and primary amines (including aniline or aniline mixed with n-butylamine or n-octylamine composition). Fourier transform infrared spectroscopy and proton nuclear magnetic resonance spectroscopy were used to characterize the structure of the monomers. The copolymers were obtained by adding the monomers into a typical monofunctional polybenzoxazine (phenol-aniline-based benzoxazine). Differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis were performed to study the thermal properties of the copolymers. The copolymers exhibited high glass transition temperature values (164–201°C). A good thermal stability was also obtained with a 5% weight loss temperature over 355°C and high char yields at 800°C (42–50%).

Synthesis and Thermal Stability of Unsaturated Polyamides

1992 ◽  
Vol 4 (2) ◽  
pp. 67-71
Author(s):  
N. R. Patel ◽  
N. Z. Patel ◽  
R. M. Patel
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Scanning Calorimetry ◽  
Aromatic Diamines ◽  
Good Thermal Stability ◽  
Kinetics Of Decomposition ◽  
Glutaconic Acid ◽  
Kinetics Of ◽  
Thermal Stability Of

Unsaturated polyamides were prepared by condensing /3(4-ethoxyphenyl) glutaconic acid with various aromatic diamines. The polycondensates were characterized by IR spectroscopy, vapor phase osmometry, thermogravimetric analysis, differential scanning calorimetry and elemental analysis. All resins were found to decompose in the range '-210-600 °C. The kinetics of decomposition were studied. The results indicated that the resins possess reasonably good thermal stability.

scholarly journals Granulation Of Porous Materials with Phase Change Material (PCM)

2021 ◽  
Vol 20 (3) ◽  
pp. 135-144
Author(s):  
Tomasz Bien
Keyword(s):  
Mechanical Strength ◽  
Phase Change ◽  
Construction Industry ◽  
Phase Change Materials ◽  
Nitrogen Adsorption ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Method Of Production ◽  
Adsorption Desorption ◽  
Change Material

The paper describes the research on the method of production of granulated phase-change materials (PCM) used in construction industry for the accumulation of thermal energy. As mineral materials for the granules preparation zeolite from fly ash Na-P1 and natural diatomite dust were used which were impregnated with paraffinic filtration waste and granulated using a combined granulation method. Obtained granules were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption/desorption isotherm, and differential scanning calorimetry (DSC). Mechanical strength of the materials was determined in a “drop strength” test. Performed analyses revealed that mineral composition and micromorphology of the diatomite and zeolite granules were varied, with zeolite granules having higher mechanical strength.

scholarly journals Synthesis and Characterization of Nanocrystalline Aluminophosphate AlPO4-5 Molecular Sieve

2018 ◽  
Vol 24 (3) ◽  
pp. 161
Author(s):  
Asir Alnaama
Keyword(s):  
Molecular Sieves ◽  
Ammonium Hydroxide ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Synthesis Parameters ◽  
Bet Analysis ◽  
Xrd Patterns ◽  
Adsorption Desorption

Nanocrystalline aluminophosphate AlPO4-5 molecular sieves were synthesized by hydrothermal method (HTS). Synthesis parameters like time and temperature of crystallization were investigated. Type of template (R) and ratio of R/P2O5 were studied also. Characterization of the synthesized AlPO4-5 were done by powder X-ray diffraction (XRD), scanning electron microscopy (SEM/EDX), Fourier transform infrared (FTIR), differential scanning calorimetry-thermogravimetry analysis (DSC-TGA), and N2 adsorption-desorption BET analysis. XRD patterns results showed excellent crystallinity for two types of templates, di-n-propylamine (DPA) and tetrapropyl ammonium hydroxide (TPAOH) for alumminophosphate five (AFI) structure. Nano-level for particle size of 66 nm was revealed by AFM test. Good thermal stability was obtained in DSC-TGA results. Best time and temperature of crystallization of 24h and 190 O C were got. Optimum R/P2O5 for two kind of template was established.  

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