scholarly journals Application of Zinc Oxide to Obtain and Modify Properties of Adipate Plasticizer of Polyvinyl Chloride

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1728
Author(s):  
Aliya K. Mazitova ◽  
Irina N. Vikhareva ◽  
Guliya K Aminova ◽  
Juliya N. Savicheva
Keyword(s):  
Thermal Stability ◽  
Zinc Oxide ◽  
Heterogeneous Catalysts ◽  
Basic Research ◽  
Scanning Calorimetry ◽  
Modern Times ◽  
Mineral Oxides ◽  
Analysis Instrument ◽  
Pvc Compositions

Heterogeneous catalysts are widely used in basic research and in the petrochemical industry due to their effectiveness. In modern times, interest in this type of catalyst and, in particular, in mineral oxides is associated with the technological design of the process, namely: The absence of waste emissions, and the possibility of regeneration and reuse of the catalyst, which meets the criteria of green chemistry. For this reason, the preparation of non-toxic adipate plasticizers is expediently carried out under conditions of heterogeneous catalysis. Zinc oxide was chosen for this purpose, and as initial reagents: Adipic acid, butoxyethanol, and phenoxyethanol. For synthesized butoxyethylphenoxyethyl adipate by thermogravimetry on a TGA-DSC-combined thermal analysis instrument and differential scanning calorimetry on a DSC-1 instrument («Mettler Toledo»), the following properties were studied: Thermal stability, melting and crystallization temperatures, polymer compatibility. An analysis of the data in comparison with di-2-ethylhexylphthalate confirmed the possibility of using it as a plasticizing additive in PVC compositions. The zinc compound obtained in situ as part of the developed plasticizing composition contributes to increasing the color and thermal stability of the obtained PVC compositions.

Preparation and Properties of PLLA-co-bis A/VMT Nanocomposites

2010 ◽  
Vol 150-151 ◽  
pp. 1466-1469
Author(s):  
Ya Li Bai ◽  
Hong Xu ◽  
Zhi Ping Mao
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
Crystallization Rate ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
Thermogravimetric Analyzer ◽  
Melt Polycondensation ◽  
The Fourier Transform

Poly(L-lactic acid)-co-bisphenol-A epoxy resin/vermiculite nanocomposites（PLLA-co-bis A /VMT）were prepared by in-situ melt polycondensation of L-LA in the presence of amino-modified vermiculite. The fourier transform infrared (FTIR) spectra were used to investigate molecular interactions between the modified vermiculite and PLLA. The detailed thermal property and crystallization behavior of samples were studied by using polarized optical microscopy (POM), differential scanning calorimetry (DSC) and thermogravimetric analyzer (TGA). The result indicated that the thermal stability, overall crystallization rate and spherulitic texture of PLLA-co-bis A were strongly influenced in the presence of vermiculite particles.

scholarly journals The Use of Epoxy Silanes on Montmorillonite: An Effective Way to Improve Thermal and Rheological Properties of PLA/MMT Nanocomposites Obtained via “In Situ” Polymerization

2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Valentina Sabatini ◽  
Hermes Farina ◽  
Luca Basilissi ◽  
Giuseppe Di Silvestro ◽  
Marco A. Ortenzi
Keyword(s):  
Thermal Stability ◽  
Rheological Properties ◽  
In Situ Polymerization ◽  
Rheological Behaviour ◽  
Size Exclusion ◽  
Melt Crystallization ◽  
Scanning Calorimetry ◽  
Molecular Weights ◽  
Exclusion Chromatography

Polylactic acid (PLA) nanocomposites were prepared via “in situ” ring opening polymerization (ROP) of lactide using a montmorillonite, Cloisite 15A, employed after surface treatment with 3-Glycidoxypropyltrimethoxysilane. The dispersion of the nanoparticles was checked using Wide Angle X-Ray Scattering (WAXS) and Transmission Electron Microscopy (TEM); both the effects of different amounts of montmorillonite and silane were measured on molecular weights and on thermal and rheological properties, using Size Exclusion Chromatography (SEC), Differential Scanning Calorimetry (DSC), thermogravimetric analyses (TGA), and rheological analyses. It was found that even very low amounts (0.1% w/w) of nanoparticles greatly affect nanocomposites properties. Unmodified montmorillonite tends to decrease molecular weights, deactivating the catalytic system used for ROP of lactide, but when epoxy silane is present molecular weights increase. Melt crystallization temperatures increase with modified nanoparticles, which enhance crystallization process. TGA analyses show that when pure montmorillonite is present, nanocomposites have lower thermal stability with respect to standard PLA; when silane is used thermal stability can get much higher than standard PLA as silane content increases. The rheological behaviour of nanocomposites shows that melt viscosity is far higher than that of standard PLA at low shear rates and also a marked shear thinning behaviour can be achieved.

Preparation and Thermal Stability of Pyrrole and m-Toluidine Copolymer/Montmorillonite Composites

2014 ◽  
Vol 915-916 ◽  
pp. 780-783
Author(s):  
Hong Wang ◽  
Ming Tian Li ◽  
Yue Lu ◽  
Di Liu
Keyword(s):  
Thermal Stability ◽  
Interfacial Interaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
X Ray ◽  
Ft Ir ◽  
Clay Layers ◽  
Thermal Stability Of

Pyrrole and m-toluidine copolymer (P(PY/MT)) / montmorillonite (MMT) Composites were prepared by in situ chemical polymerization of pyrrole with m-toluidine monomer in the presence of montmorillonite. The structural, morphological and thermal properties of these composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). X-ray diffraction result for P(PY/MT)-MMT illuminated the intercalation of P(PY/MT) copolymer between the clay layers. The FT-IR result showed the successful incorporation of montmorillonite clay in the prepared P(PY/MT)/MMT composite. The higher thermal stability of high MMT content rate might be attributed to its higher chain compactness due to the interfacial interaction between the P(PY/MT) and the clay.

scholarly journals Reactive Energetic Plasticizers Utilizing Cu-Free Azide-alkyne 1,3-dipolar Cycloaddition for In-Situ Preparation of Poly(THF-co-GAP)-Based Polyurethane Energetic Binders

2018 ◽  
Author(s):  
Mingyang Ma ◽  
Younghwan Kwon
Keyword(s):  
Thermal Stability ◽  
Dipolar Cycloaddition ◽  
Resonance Spectroscopy ◽  
Solid Propellants ◽  
Scanning Calorimetry ◽  
In Situ Preparation ◽  
1H Nuclear Magnetic Resonance ◽  
Energetic Plasticizers ◽  
Thermal Stability Of

Reactive energetic plasticizers (REPs) coupled with hydroxy-telechelic poly(glycidyl azide-co-tetrahydrofuran) (PGT)-based energetic polyurethane (PU) binders for use in solid propellants and plastic-bonded explosives (PBXs) were investigated. The generation of gem-dinitro REPs along with a terminal alkyne stemmed from a series of finely designed approaches to not only satisfy the common demands as conventional energetic plasticizers but prevent the migration of plasticizers. The miscibility and rheological behavior of a binary mixture of PGT/REP with various REP fractions were quantitatively determined by differential scanning calorimetry (DSC) and rheometer, respectively, highlighting the promising performance of REPs in the formulation process. The kinetics on the distinct reactivity of propargyl vs. 3-butynyl species of REPs towards the azide group of the PGT prepolymer in terms of Cu-free azide-alkyne 1,3-dipolar cycloaddition (1,3-DPCA) was studied by monitoring 1H nuclear magnetic resonance spectroscopy and analyzing the activation energies (Ea) obtained using DSC. The thermal stability of the finally cured energetic binders with the incorporation of REPs indicated that the thermal stability of the REP/PGT-based PUs was maintained independently of the REP content. The tensile strength and modulus of the PUs increased with increasing the REP content. In addition, the energetic performance and sensitivity of REP and REP triazole species was predicted.

Synthesis and characterization of siloxane-containing benzoxazines with high thermal stability

2019 ◽  
Vol 32 (3) ◽  
pp. 268-275 ◽  
Author(s):  
Hui Li ◽  
Jilei Xu ◽  
Kai Zeng ◽  
Yuntao Li ◽  
Chunxia Zhao Gaoxu Li
Keyword(s):  
Thermal Stability ◽  
Infrared Spectra ◽  
Modulated Dsc ◽  
Resonance Imaging ◽  
Scanning Calorimetry ◽  
Ether Linkage ◽  
Low Viscosity ◽  
Aromatic Content

To understand the influence of phenyl substituents on silicon and to improve the glass transition temperature ( T g) and thermal stability, phenol/bis ( p-aminophenoxyl) dimethylsiloxane-based benzoxazine (P-adms), phenol/bis ( p-aminophenoxyl) methylphenylsiloxane-based benzoxazine (P-amps), and phenol/bis ( p-aminophenoxyl) diphenylsiloxane-based benzoxazine (P-adps) were designed and synthesized. The structure of the siloxane-containing benzoxazines were confirmed by proton and carbon nuclear magnetic resonance imaging and Fourier transform infrared spectra. The curing reaction of the obtained benzoxazines was studied by differential scanning calorimetry (DSC) and in situ infrared spectra. The influence of the aromatic content on the T g and thermal stability were investigated by modulated DSC and thermogravimetric analysis. Compared to aminopropylsiloxane-based benzoxazines, the bis ( p-aminophenoxyl) siloxane-based benzoxazines possessed relatively higher T g about 140°C due to the replacement of flexible propyl chain by phenoxyl chain. With increasing phenyl substituents on silicon, the polybenzoxazines possessed lower T g and higher thermal stability. It is notedthat the phenol/bis ( p-aminophenoxyl) diphenylsiloxane-based benzoxazine (P-adps) still has low viscosity despite high aromatic content due to the flexible ether linkage (Ar–O–Si).

Preparation of Poly(m-toluidine)/Montmorillonite Composites and its Thermal Stability

2014 ◽  
Vol 941-944 ◽  
pp. 334-337
Author(s):  
Hong Wang ◽  
Rui Song Yang ◽  
Ying Wang
Keyword(s):  
Thermal Stability ◽  
Interfacial Interaction ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
X Ray ◽  
Ft Ir ◽  
Clay Layers ◽  
Thermal Stability Of

Poly (m-toluidine)(PMT) / montmorillonite (MMT) Composites with thermal stability were synthesized by in situ chemical polymerization of m-toluidine monomer in the presence of montmorillonite. The PMT /MMT composites were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). The FT-IR result displayed the successful incorporation of montmorillonite clay in the prepared PMT/MMT composite. X-ray diffraction result for PMT/MMT showed the intercalation of PMT between the clay layers. The higher thermal stability of high MMT content rate might be attributed to its higher chain compactness due to the interfacial interaction between the PMT and the .MMT.

Mechanical Alloying of Ti-Al-Si-C Powders, their Thermal Stability, Phase Evolution, and Synthesis and Deformation of In Situ Produced Titanium Aluminide Composites

2007 ◽  
Vol 340-341 ◽  
pp. 83-88 ◽  
Author(s):  
K.P. Rao ◽  
A. Vyas
Keyword(s):  
Thermal Stability ◽  
Mechanical Alloying ◽  
Titanium Aluminide ◽  
Structural Changes ◽  
Elevated Temperatures ◽  
Elemental Powder ◽  
Stable Phase ◽  
Dispersion Strengthening ◽  
Scanning Calorimetry

Addition of silicon promotes the development of a stable phase Ti5Si3 through thermomechanical treatment in TiAl-based alloys develop, while carbon seems to be a promising element for generating both solid solution effect and dispersion strengthening by precipitation of TiC or Ti2AlC during subsequent processing of such alloys. In this study, elemental powder mixture of 58Ti-30Al-6Si-6C (at%) was selected to find the structural changes during mechanical alloying (MA) process in order to understand the mechanism of alloying as well as study the subsequent thermal stability and evolution of phases. The results obtained would be useful towards in situ synthesis of titanium aluminide composites that are targeted to serve applications involving high tempearture. Such route will enable precipitation of harder Ti5Si3 and TiC particles within a matrix of TiAl through hot isostatic pressing (HIP). Firstly, MA of the chosen powder mix was performed up to 40 hours. The structural evolution of MA powders and/or annealed powders was characterized by X-ray diffraction (XRD). The stability of milled powders was investigated by differential scanning calorimetry (DSC) to study the phase transformations. Then, 10% of MA powder or the so called ‘precursor’ was incorporated into Ti-45Al-2Cr-4Nb-1.5Mn (at%) baseline matrix or baseline elemental powder, and was packed into stainless steel tubes after thorough blending. The sealed tubes were subjected to HIPing under a pressure of 150 MPa at 1100°C for 4 hours, followed by furnace cooling to room temperature. After HIPing, the resulted composites were annealed at 1150°C for 4 hours. The composites were evaluated for their mechanical properties and deformability at room and elevated temperatures. The results indicate that the synthesized composites have indicated extensive workability at a temperature of 800 oC as well as good mechanical proporties up to this temperature.

Thermal gravimetric analysis of in-situ crosslinked nanocellulose whiskers • poly(methyl vinyl ether-co-maleic acid) • polyethylene glycol

TAPPI Journal ◽  
2011 ◽  
Vol 10 (4) ◽  
pp. 29-33
Author(s):  
LEE A. GOETZ ◽  
AJI P. MATHEW ◽  
KRISTIINA OKSMAN ◽  
ARTHUR J. RAGAUSKAS
Keyword(s):  
Thermal Stability ◽  
Polyethylene Glycol ◽  
Vinyl Ether ◽  
Thermal Gravimetric Analysis ◽  
Maleic Acid ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Methyl Vinyl ◽  
Methyl Vinyl Ether

The thermal stability and decomposition of in-situ crosslinked nanocellulose whiskers – poly(methyl vinyl ether-co-maleic acid) – polyethylene glycol formulations (PMVEMA-PEG), (25%, 50%, and 75% whiskers) – were investigated using thermal gravimetric analysis (TGA) methods. The thermal degradation behavior of the films varied according to the percent cellulose whiskers in each formulation. The presence of cellulose whiskers increased the thermal stability of the PMVEMA-PEG matrix.

Thermal Stability of N-Heterocycle-Stabilized Iodanes – A Systematic Investigation

2019 ◽  
Author(s):  
Andreas Boelke ◽  
Yulia A. Vlasenko ◽  
Mekhman S. Yusubov ◽  
Boris Nachtsheim ◽  
Pavel Postnikov
Keyword(s):  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Thermogravimetric Analysis ◽  
Systematic Investigation ◽  
Scanning Calorimetry ◽  
Thermal Stability Of

<p>The thermal stability of pseudocyclic and cyclic <i>N</i>-heterocycle-stabilized (hydroxy)aryl- and mesityl(aryl)-l<sup>3</sup>-iodanes (NHIs) through thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is investigated. NHIs bearing <i>N</i>-heterocycles with a high N/C-ratio such as triazoles show among the lowest descomposition temperatures and the highest decomposition energies. A comparison of NHIs with known (pseudo)cyclic benziodoxolones is made and we further correlated their thermal stability with reactivity in a model oxygenation. </p>

Injectable in-situ Forming Depot Of Doxycycline Hyclate/α-Cyclodextrin Complex using PLGA for Periodontitis Treatment: Preparation, Charac-terization, and In-Vitro Evaluation

2020 ◽  
Vol 17 ◽  
Author(s):  
Elham Khodaverdi ◽  
Farhad Eisvand ◽  
Mohammad Sina Nezami ◽  
Seyedeh Nesa Rezaeian Shiadeh ◽  
Hossein Kamali ◽  
...  
Keyword(s):  
Complex Form ◽  
Docking Studies ◽  
Morphological Properties ◽  
Burst Release ◽  
Cyclodextrin Complex ◽  
Doxycycline Hyclate ◽  
Scanning Calorimetry ◽  
In Situ Forming

Background:: Doxycycline (DOX) is used in treating a bacterial infection, especially for periodontitis treatment. Objective: To reduce irritation of DOX for subgingival administration and increase the chemical stability and against enzy-matic, the complex of α-cyclodextrin with DOX was prepared and loaded into injectable in situ forming implant based on PLGA. Methods:: FTIR, molecular docking studies, X-ray diffraction, and differential scanning calorimetry was performed to char-acterize the DOX/α-cyclodextrin complex. Finally, the in-vitro drug release and modeling, morphological properties, and cellular cytotoxic effects were also evaluated. Results:: The stability of DOX was improved with complex than pure DOX. The main advantage of the complex is the al-most complete release (96.31 ± 2.56 %) of the drug within 14 days of the implant, whereas in the formulation containing the pure DOX and the physical mixture the DOX with α-cyclodextrin release is reached to 70.18 ± 3.61 % and 77.03 ± 3.56 %, respectively. This trend is due to elevate of DOX stability in the DOX/ α-cyclodextrin complex form within PLGA implant that confirmed by the results of stability. Conclusion:: Our results were indicative that the formulation containing DOX/α-cyclodextrin complex was biocompatible and sustained-release with minimum initial burst release.

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