scholarly journals Preparation and Characterization of DOPO-ITA Modified Ethyl Cellulose and Its Application in Phenolic Foams

Polymers ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1049 ◽  
Author(s):  
Yufeng Ma ◽  
Xuanang Gong ◽  
Chuhao Liao ◽  
Xiang Geng ◽  
Chunpeng Wang ◽  
...  
Keyword(s):  
Ethyl Cellulose ◽  
Phenolic Resin ◽  
Residual Carbon ◽  
Cell Distribution ◽  
Phenolic Resins ◽  
Reaction Orders ◽  
Ft Ir ◽  
Additive Compound ◽  
Structure And Microstructure

In order to improve the performance of phenolic foam, an additive compound of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and Itaconic acid (ITA) were attached on the backbone of ethyl cellulose (EC) and obtained DOPO-ITA modified EC (DIMEC), which was used to modify phenolic resin and composite phenolic foams (CPFs). The structures of DOPO-ITA were verified by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance (1H NMR). The molecular structure and microstructure were characterized by FT-IR spectra and SEM, respectively. Compared with EC, the crystallinity of DIMEC was dramatically decreased, and the diffraction peak positions were basically unchanged. Additionally, thermal stability was decreased and Ti decreased by 24 °C. The residual carbon (600 °C) was increased by 25.7%. With the dosage of DIMEC/P increased, the Ea values of DIMEC composite phenolic resins were increased gradually. The reaction orders were all non-integers. Compared with PF, the mechanical properties, flame retardancy, and the residual carbon (800 °C) of CPFs were increased. The cell size of CPFs was less and the cell distribution was relatively regular. By comprehensive analysis, the suitable dosage of DIMEC/P was no more than 15%.

Physicochemical Characterization of Oxidatively Degraded Calcium Lignosulfonate via Alkaline Hydrogen Peroxide

2014 ◽  
Vol 887-888 ◽  
pp. 575-580 ◽  
Author(s):  
Li Hong Hu ◽  
Jing Zhou ◽  
Cai Ying Bo ◽  
Bing Chuan Liang ◽  
Yong Hong Zhou
Keyword(s):  
Hydrogen Peroxide ◽  
Phenolic Resin ◽  
Physicochemical Characterization ◽  
Oxidative Degradation ◽  
Alkaline Condition ◽  
Alkaline Hydrogen Peroxide ◽  
Phenolic Contents ◽  
H Nmr ◽  
Ft Ir

In order to increase the application prospect of calcium lignosulfonate in phenolic resin, Calcium lignosulfonate was oxidatively degraded by Hydrogen peroxide under alkaline condition. Both lignins were characterized by FT-IR, 1H NMR, UV, GC-MS and GPC. The optimal degradation conditions are: lignosulfonate:water=1:1, wt/wt, pH=10, temperature 60 °C, reaction time 2 h, and H2O2 dosage 6 wt% (based on weight of lignosulfonate). The results show that the degraded resultant is higher in phenolic contents, and lower in methoxyl content. Number molecular weight (Mn) of calcium lignosulfonate sharply decreases to 2294, versus 17774 before oxidative degradation.Guaiacly monoer content increased and kinds of phenolic compounds occurre in oxidative degradation fractions, mainly due to β-O-4 and β-5 cleavage. And reactive activity of the oxidatively degraded compounds is sharply increased.

Preparation and Characterization of Tenofovir Disoproxil-Loaded Enteric Microparticle

2020 ◽  
Vol 20 (9) ◽  
pp. 5796-5799
Author(s):  
Young Hoon Kim ◽  
Yu-Chul Kim ◽  
Jae Yeol Kim ◽  
Jimi Byeon ◽  
Han-Joo Maeng ◽  
...  
Keyword(s):  
Ethyl Cellulose ◽  
Intestinal Tract ◽  
Physicochemical Characterization ◽  
Mixed Structure ◽  
Medium Ph ◽  
Sem Image ◽  
Single Use ◽  
Ft Ir ◽  
Ir Analysis

Tenofovir disoproxil (TD) has narrow absorption site mostly in upper intestinal tract where tenofovir rapidly decomposes. The aim of this work was to prepare and evaluate tenofovir disoproxil-loaded enteric microparticles (TDEMs) for the enhanced duodenal delivery. TDEMs were composed of TD, eudragit L-100 (EL) and ethyl cellulose (EC) as release-controlling polymers. For the physicochemical characterization, TDEMs were evaluated in terms of encapsulation efficiency (EE%), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR). The dissolution test was also performed while continuously changing the medium pH. The EE% of TD in TDEMs was good and more than 90%. The EC and EL formed a physically mixed structure and maintained their respective properties in TDEMs as confirmed by SEM image and FT-IR analysis. Combination of EL and EC gave higher enteric properties to TDEMs than the single use of EL or EC. The optimized TDEM (TD/EL/EC = 0.2/1/1, w/w/w ratio) yielded mean dissolution rate less than 10% in 1 h at pH 1.2, but completed dissolution with a dissolution more than 85% within 1 h at pH 6.5. Thus, the suggested TDEM would be promising enteric microparticles for the intensive delivery of TD to the duodenum.

scholarly journals Preparation and Characterization of Phenolic Foam Modified with Bio-Oil

Materials ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 2228 ◽  
Author(s):  
Yuxiang Yu ◽  
Yufei Wang ◽  
Pingping Xu ◽  
Jianmin Chang
Keyword(s):  
Phenolic Resin ◽  
Oh Groups ◽  
Phenolic Foam ◽  
Bio Oil ◽  
Residual Masses ◽  
Ft Ir ◽  
Flame Retardant Properties ◽  
Mechanical Performances ◽  
The Fourier Transform

Bio-oil was added as a substitute for phenol for the preparation of a foaming phenolic resin (PR), which aimed to reduce the brittleness and pulverization of phenolic foam (PF). The components of bio-oil, the chemical structure of bio-oil phenolic resin (BPR), and the mechanical performances, and the morphological and thermal properties of bio-oil phenolic foam (BPF) were investigated. The bio-oil contained a number of phenols and abundant substances with long-chain alkanes. The peaks of OH groups, CH2 groups, C=O groups, and aromatic skeletal vibration on the Fourier transform infrared (FT-IR) spectrum became wider and sharper after adding bio-oil. These suggested that the bio-oil could partially replace phenol to prepare resin and had great potential for toughening resin. When the substitute rate of bio-oil to phenol (B/P substitute rate) was between 10% and 20%, the cell sizes of BPFs were smaller and more uniform than those of PF. The compressive strength and flexural strength of BPFs with a 10–20% B/P substitute rate increased by 10.5–47.4% and 25.0–50.5% respectively, and their pulverization ratios decreased by 14.5–38.6% in comparison to PF. All BPFs maintained good flame-retardant properties, thermal stability, and thermal isolation, although the limited oxygen index (LOI) and residual masses by thermogravimetric (TG) analysis of BPFs were lower and the thermal conducticity was slightly greater than those of PF. This indicated that the bio-oil could be used as a renewable toughening agent for PF.

Synthesis and Characterization of Acrylamide Based Benzoxazine

2012 ◽  
Vol 621 ◽  
pp. 11-16
Author(s):  
Erigene Bakangura ◽  
Zhong Yu Luo ◽  
Guang Kai Wang ◽  
Yang Bin ◽  
Yan Ping Yue ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Phenolic Resin ◽  
Curing Temperature ◽  
Hydroxyl Group ◽  
Synthesis And Characterization ◽  
Oxazine Ring ◽  
Ft Ir ◽  
Thermal Stability Of ◽  
Direct Condensation

Novel benzoxazine monomers, acrylamide based benzoxazine, have been prepared from direct condensation of phenols with acrylamide and formaldehyde. 1H NMR and FT-IR, DSC and TGA were used to analysis the structure, compositions and investigate the curing behaviour and thermal stability, respectively. Solvent effects were studied. Solventless method is good for higher formation ratio of benzoxazine to the corresponding phenolic resin. The ratio for P-AA is 36.4% by solventless method, while it’s about 26% by toluene solvent; and 44% and 20% for B-AA, respectively. The monomers mixtures exhibit curing temperature (ca.187oC) without catalysts lower than their related allyl-benzoxazine. The FT-IR of different curing temperature shows the disappearance of double bond absorption at 1668 cm-1 and oxazine ring at 1232 cm-1 and appearance of hydroxyl group at 3446 cm-1. Thermal stability of cured benzoxazine show good char residues compared with traditional benzoxazine of aniline.

Spectral Investigation on the Growth and Characterization of NLO Crystals of Thiourea Succinic Acid Single Crystal.

2015 ◽  
Vol 2 (2) ◽  
pp. 70-73
Author(s):  
Kannan.P ◽  
Thambidurai.S ◽  
Suresh.N
Keyword(s):  
Single Crystal ◽  
Succinic Acid ◽  
Slow Evaporation Technique ◽  
Absorption Studies ◽  
Dta Analysis ◽  
Evaporation Technique ◽  
Ft Ir ◽  
Ir Spectroscopic ◽  
Thermal Stability Of

Growth of optically transparent single crystals of thiourea succinic acid (TUSA) was grown successfully from aqueous solution by slow evaporation technique. The crystal structure was elucidated using the single crystal XRD. The various functional groups and the modes of vibrations were identified by FT-IR spectroscopic analysis. The optical absorption studies indicate that the optical transparency window is quite wide making its suitable for NLO applications. Thermal stability of the crown crystal carried out by TGA-DTA analysis.

Characterization of Vacuum Pyrolysis Products from Phenolic Resin Laminate Substrate

2010 ◽  
Vol 38 (1) ◽  
pp. 72-76
Author(s):  
Wen-Biao WU ◽  
Ke-Qiang QIU ◽  
Cheng-Long LI ◽  
Xiao-Qun XU
Keyword(s):  
Phenolic Resin ◽  
Pyrolysis Products ◽  
Vacuum Pyrolysis

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.

Preparation and Characterization of Soybean Oil-based Flame Retardant Rigid Polyurethane Foams Containing Phosphaphenanthrene Groups

2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang
Keyword(s):  
Soybean Oil ◽  
Flame Retardant ◽  
Chemical Structure ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Degradation Activation Energy ◽  
Ft Ir

A phosphaphenanthrene groups containing soybean oil based polyol (DSBP) was synthesized by epoxidized soybean oil (ESO) and 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Soybean oil based polyol (HSBP) was synthesized by ESO and H2O. The chemical structure of DSBP and HSBP were characterized with FT-IR and 1H NMR. The corresponding rigid polyurethane foams (RPUFs) were prepared by mixing DSBP with HSBP. The results revealed apparent density and compression strength of RPUFs decreased with increasing the DSBP content. The cell structure of RPUFs was examined by scanning electron microscope (SEM) which displayed the cells as spherical or polyhedral. The thermal degradation and flame retardancy of RPUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL 94 vertical burning test. The degradation activation energy (Ea) of first degradation stage reduced from 80.05 kJ/mol to 37.84 kJ/mol with 80 wt% DSBP. The RUPF with 80 wt% DSBP achieved UL94 V-0 rating and LOI 28.3. The results showed that the flame retardant effect was mainly in both gas phase and condensed phase.

Isolasi Dan Karakterisasi Bentonit Alam Menjadi Nanopartikel Monmorillonit

2018 ◽  
Vol 3 (1) ◽  
pp. 12 ◽  
Author(s):  
Zaimahwati Zaimahwati ◽  
Yuniati Yuniati ◽  
Ramzi Jalal ◽  
Syahman Zhafiri ◽  
Yuli Yetri
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Particle Size ◽  
Surface Morphology ◽  
Average Diameter ◽  
Particle Size Analyzer ◽  
Ft Ir ◽  
Scanning Electron ◽  
Sedimentation Processes

<p>Pada penelitian ini telah dilakukan isolasi dan karakterisasi bentonit alam menjadi nanopartikel montmorillonit. Bentonit alam yang digunakan diambil dari desa Blangdalam, Kecamatan Nisam Kabupaten Aceh Utara.  Proses isolasi meliputi proses pelarutan dengan aquades, ultrasonic dan proses sedimentasi. Untuk mengetahui karakterisasi montmorillonit dilakukan uji FT-IR, X-RD dan uji morfologi permukaan dengan Scanning Electron Microscopy (SEM). Partikel size analyzer untuk menganalisis dan menentukan ukuran nanopartikel dari isolasi bentonit alam. Dari hasil penelitian didapat ukuran nanopartikel montmorillonit hasil isolasi dari bentonit alam diperoleh berdiameter rata-rata 82,15 nm.</p><p><em>In this research we have isolated and characterized natural bentonite into montmorillonite nanoparticles. Natural bentonite used was taken from Blangdalam village, Nisam sub-district, North Aceh district. The isolation process includes dissolving process with aquades, ultrasonic and sedimentation processes.  The characterization of montmorillonite, FT-IR, X-RD and surface morphology test by Scanning Electron Microscopy (SEM). Particle size analyzer to analyze and determine the size of nanoparticles from natural bentonite insulation. From the research results obtained the size of montmorillonite nanoparticles isolated from natural bentonite obtained an average diameter of 82.15 nm.</em></p>

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