Spherical PF resin beads prepared from phenol-liquefied Bambusa dolichoclada with suspension polymerization

Holzforschung ◽  
2011 ◽  
Vol 65 (2) ◽  
Author(s):  
Wen-Jau Lee ◽  
Chao-Yun Yu ◽  
Kuo-Chun Chang ◽  
Ying-Pin Huang ◽  
Ching-Hui Chang ◽  
...  
Keyword(s):  
Phenol Formaldehyde ◽  
Suspension Polymerization ◽  
Raw Material ◽  
Molar Ratio ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Free Phenol ◽  
Resin Beads ◽  
Dimensional Distribution

Abstract Bambusa dolichoclada Hayata (long-shoot bamboo) was liquefied in phenol with H2SO4 as a catalyst. The phenol-liquefied bamboo was then used as a raw material to prepare spherical phenol-formaldehyde (PF) resin beads by a suspension polymerization in a two-step process. The influence of the stirring speed (300, 350 and 400 rpm), the stabilizer dosage (3%, 4% and 5%) and the total molar ratio of formaldehyde to free phenol (F/P) (3.0/1, 3.5/1 and 4.0/1) on the properties of spherical PF beads was investigated. The results show that the yield, diameter and dimensional distribution of prepared PF beads were influenced by reaction conditions. The diameter of beads decreased as the stabilizer dosage increased. It had a more uniform dimensional distribution when stirred with a speed of 400 rpm. Differential scanning calorimetry analysis shows that PF beads obtained were not completely cured and the post-curing reaction took place at temperatures exceeded 150°C. As revealed by thermal gravimetric analysis, the char yield was over 60% after heating to 800°C.

scholarly journals Synthesis and thermal properties of some phenolic resins

2019 ◽  
Vol 7 (1) ◽  
pp. 1-15
Author(s):  
Alshawi F M ◽  
Abdul Razzq K ◽  
Hanoosh W S
Keyword(s):  
Phenol Formaldehyde ◽  
Chemical Properties ◽  
Decomposition Temperature ◽  
Industrial Applications ◽  
Stability Study ◽  
Curing Temperature ◽  
Molar Ratio ◽  
Scanning Calorimetry ◽  
Phenolic Resins ◽  
Physical And Chemical

Introduction: Phenolic resins have been in use since the early twentieth century and are considered the first class of synthetic polymers to achieve commercial success, moreover phenolic resins continue to succeed and attract special interest in a large range of industrial applications such as adhesives, paints, and composites; because of their unique physical and chemical properties. Materials and Methods: Prepolymers resol resins (RR, RH, RP, and RC) were synthesized by the reaction of phenolic compounds (resorcinol, hydroquinone, phloroglucinol, and catechol) respectively, with formaldehyde at molar ratio phenol/ formaldehyde 1/1.5, using sodium hydroxide as a catalyst. These resins were characterized by FTIR. The curing reaction of these resins was evaluated using differential scanning calorimetry (DSC), while the thermal stability study was evaluated using thermogravimetric analysis (TGA). Results and Discussion:From the results showing that these prepolymers have different curing temperatures and curing energy, while the TGA study showed that the cured resins have decomposition temperature more than 300 ºC, and char residue at 650 ºC more than 60%. Conclusions: These resol resins have different gel times (8-55) min, and viscosities (435-350) mpa.s. The curing temperature of these resin obtained from DSC curves was (120, 129, 105 and 127 °C), while the thermal behavior of the cured resins obtained from TGA curves showed that these cured resin have two decomposition temperatures and the rate of decomposition in the order of RC < RR< .

Borax Modify Phenol-Formaldehyde Resin as Wood Adhesives

2012 ◽  
Vol 610-613 ◽  
pp. 507-513 ◽  
Author(s):  
Rui Hang Lin ◽  
Xiao Feng Zhu ◽  
Xiao Bo Wang ◽  
Zhen Zhong Gao
Keyword(s):  
Phenol Formaldehyde ◽  
Thermodynamic Characteristics ◽  
Phenol Formaldehyde Resin ◽  
Curing Temperature ◽  
Alkaline Condition ◽  
Formaldehyde Resin ◽  
Scanning Calorimetry ◽  
Free Phenol ◽  
Thermo Gravimetric Analyzer ◽  
Infrared Spectrometer

A modified phenol-formaldehyde (PF) resin was synthesized under alkaline condition in varying proportion of borax up to 21% (w/w). All the prepared resin were characterized by free phenol content, free formaldehyde content as well as hydroxymethyl content. It was proved by Fourier transform infrared spectrometer (FTIR) that B-O bond had been successfully introduced into the structure of PF resin. Thermo gravimetric analyzer (TGA) and different scanning calorimetry (DSC) were used to characterize the thermodynamic characteristics of the PF resin. The result showed that when the mass fraction of borax was 9wt.% of PF resin, the heat resistance was the best and the curing temperature of the modified PF resin was higher than that of the unmodified PF resin.

scholarly journals Kinetic Study on the CsXH3−XPW12O40/Fe-SiO2Nanocatalyst for Biodiesel Production

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Mostafa Feyzi ◽  
Leila Norouzi ◽  
Hamid Reza Rafiee
Keyword(s):  
Kinetic Study ◽  
Biodiesel Production ◽  
Molar Ratio ◽  
Esterification Reaction ◽  
Gravimetric Analysis ◽  
Time Data ◽  
Scanning Calorimetry ◽  
Experimental Conditions ◽  
Heterogeneous Catalytic ◽  
Operation Conditions

The kinetic of the transesterification reaction over theCsXH3−XPW12O40/Fe-SiO2catalyst prepared using sol-gel and impregnation procedures was investigated in different operational conditions. Experimental conditions were varied as follows: reaction temperature 323–333 K, methanol/oil molar ratio = 12/1, and the reaction time 0–240 min. The H3PW12O40heteropolyacid has recently attracted significant attention due to its potential for application in the production of biodiesel, in either homogeneous or heterogeneous catalytic conditions. Although fatty acids esterification reaction has been known for some time, data is still scarce regarding kinetic and thermodynamic parameters, especially when catalyzed by nonconventional compounds such as H3PW12O40. Herein, a kinetic study utilizing Gc-Mas in situ allows for evaluating the effects of operation conditions on reaction rate and determining the activation energy along with thermodynamic constants includingΔG,ΔS, andΔH. It indicated that theCsXH3−XPW12O40/Fe-SiO2magnetic nanocatalyst can be easily recycled with a little loss by magnetic field and can maintain higher catalytic activity and higher recovery even after being used 5 times. Characterization of catalyst was carried out by using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), N2adsorption-desorption measurements methods, thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC).

Synthesis and Characterization of Poly (styrene-co-butyl acrylate)/Silica Aerogel Nanocomposites by in situ AGET ATRP: Investigating Thermal Properties

2017 ◽  
Vol 36 (10) ◽  
pp. 955-962 ◽  
Author(s):  
Khezrollah Khezri ◽  
Yousef Fazli
Keyword(s):  
Molecular Weight ◽  
Butyl Acrylate ◽  
Silica Aerogel ◽  
Size Exclusion ◽  
Proton Nuclear Magnetic Resonance ◽  
Molar Ratio ◽  
Resonance Spectroscopy ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Exclusion Chromatography

AbstractHydrophilic silica aerogel nanoparticles surface was modified with hexamethyldisilazane. Then, the resultant modified nanoparticles were used in random copolymerization of styrene and butyl acrylate via activators generated by electron transfer for atom transfer radical polymerization. Conversion and molecular weight determinations were performed using gas and size exclusion chromatography respectively. Addition of modified nanoparticles by 3 wt% results in a decrease of conversion from 68 to 46 %. Molecular weight of copolymer chains decreases from 12,500 to 7,500 g.mol–1 by addition of 3 wt% modified nanoparticles; however, PDI values increase from 1.1 to 1.4. Proton nuclear magnetic resonance spectroscopy results indicate that the molar ratio of each monomer in the copolymer chains is approximately similar to the initial selected mole ratio of them. Increasing thermal stability of the nanocomposites is demonstrated by thermal gravimetric analysis. Differential scanning calorimetry also shows a decrease in glass transition temperature by increasing modified silica aerogel nanoparticles.

Research on Synthesis Regularity of Epoxysuccinic Acid

2013 ◽  
Vol 316-317 ◽  
pp. 942-945
Author(s):  
Qing He Gao ◽  
Yi Can Wang ◽  
Zhi Feng Hou ◽  
Hui Juan Qian ◽  
Yuan Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Maleic Anhydride ◽  
Reaction Temperature ◽  
Raw Material ◽  
Molar Ratio ◽  
Mass Ratio ◽  
Synthesis System ◽  
Reaction Conditions ◽  
Sodium Hydrate

The yield of epoxysuccinic acid was obtained by determining the content of unreacted maleic anhydride and tartaric acid as a by-product in synthesis system. This method could calculate the yield of epoxysuccinic acid precisely and overcome the disadvantage of obtaining inpure product by recrystallization method. Epoxysuccinic Acid was synthesized using maleic anhydride as raw material, hydrogen peroxide as oxidizer and tungstate as catalyst. The effects of reaction temperature, reaction time, ratio of materials, dosage of oxidizer and catalyst on epoxidation and hydrolysis reaction was investigated. The results showed that the yield of epoxysuccinic acid was 88% when the reaction conditions were as follows: reaction temperature 65°C, reaction time 1.5h, catalyst dosage 3%(based on mass of maleic anhydride), molar ratio of sodium hydrate to maleic anhydride 2:1, mass ratio of hydrogen peroxide to maleic anhydride 1:1.

scholarly journals Fluconazole-tartaric acid co-crystal formation and its mechanical properties

2021 ◽  
pp. 116-122
Author(s):  
Fikri Alatas ◽  
Nia Suwartiningsih ◽  
Hestiary Ratih ◽  
Titta Hartyana Sutarna
Keyword(s):  
Mechanical Properties ◽  
Tartaric Acid ◽  
Crystal Morphology ◽  
Active Pharmaceutical Ingredient ◽  
Raw Material ◽  
Molar Ratio ◽  
Crystal Formation ◽  
Polarization Microscopy ◽  
Scanning Calorimetry ◽  
Pxrd Pattern

Introduction: The formation of co-crystal is widely studied to obtain more favourable physicochemical properties than the pure active pharmaceutical ingredient (API). The co-crystal formation between an anti-fungal drug, fluconazole (FLU), and tartaric acid (TAR) has been investigated and its impact on mechanical properties has also been studied. Methods: The co-crystal of FLU-TAR (1:1) molar ratio was prepared by ultrasound-assisted solution co-crystallization (USSC) method with ethanol as the solvent. Polarization microscopy was used to observe the crystal morphology. Meanwhile, powder X-ray diffraction (PXRD) and differential scanning calorimetry (DSC) methods were used to characterise the co-crystal formation. The mechanical properties of the co-crystal, such as flowability and tablet-ability, were compared with pure FLU. Results: Photomicroscopes revealed the unique crystal morphology of the USSC product was different from the two starting components. The typical PXRD pattern was shown by the USSC product, which indicated the formation of FLU-TAR co-crystal. In addition, the DSC thermogram revealed 169.2°C as the melting point of the FLU-TAR co-crystal, which is between the melting points of FLU and TAR. It indicates that FLU-TAR co-crystal has better flowability and tablet-ability than pure FLU. Conclusion: FLU-TAR co-crystal is one of the alternative solid forms for a raw material in pharmaceutical tablet preparation because it has better mechanical properties than pure fluconazole.

scholarly journals Heterocyclic Hypervalent Iodine(III) Compounds with Fused Benziodazole and Tetrazole Rings (I-Substituted Tetrazolo[1,5-b][1,2]Benziodazoles)

2020 ◽  
Author(s):  
Rajesh Kumar ◽  
Kapil Dev Sayala ◽  
Lejla Lejla Camdzic ◽  
Maxime Siegler ◽  
Avichal Vaish ◽  
...  
Keyword(s):  
Room Temperature ◽  
Hypervalent Iodine ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Thermal Stabilities ◽  
X Ray ◽  
X Ray Crystallography ◽  
Derivatives Of ◽  
C Nmr

A series of heterocyclic hypervalent (HV) iodine(III) compounds containing fused tetrazole and benziodazole rings, i.e., derivatives of benziodazolotetrazole (BIAT) with various ligands (L) attached to the iodine atom (BIAT-L) were prepared and studied. They were characterized by <sup>1</sup>H and <sup>13</sup>C NMR spectroscopy, ESI-HRMS, and X-ray crystallography. The thermal stabilities of all BIAT derivatives (L= Cl, OH, OAc, OMe) were studied and the degradation patterns as well as the enthalpies of degradation were measured by thermal gravimetric analysis coupled with differential scanning calorimetry. The reaction of various alkenes with BIAT-Cl in the presence of Cu(OTf)<sub>2</sub> at room temperature yielded chloro-tetrazolylated products. The oxidation of thioanisole with BIAT-Cl under various reaction conditions is also reported.

scholarly journals Fluoropolymer/Glycidyl Azide Polymer (GAP) Block Copolyurethane as New Energetic Binders: Synthesis, Mechanical Properties, and Thermal Performance

Polymers ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2706
Author(s):  
Minghui Xu ◽  
Xianming Lu ◽  
Ning Liu ◽  
Qian Zhang ◽  
Hongchang Mo ◽  
...  
Keyword(s):  
Thermal Performance ◽  
Mechanical Performance ◽  
Gel Permeation Chromatography ◽  
Raw Material ◽  
Toluene Diisocyanate ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Glycidyl Azide Polymer ◽  
The Impact ◽  
Glycidyl Azide

In order to enhance the application performance of glycidyl azide polymer (GAP) in solid propellant, an energetic copolyurethane binder, (poly[3,3-bis(2,2,2-trifluoro-ethoxymethyl)oxetane] glycol-block-glycidylazide polymer (PBFMO-b-GAP) was synthesized using poly[3,3-bis(2,2,2-trifluoro-ethoxymethyl)oxetane] glycol (PBFMO), which was prepared from cationic polymerization with GAP as the raw material and toluene diisocyanate (TDI) as the coupling agent via a prepolymer process. The molecular structure of copolyurethanes was confirmed by attenuated total reflectance-Fourier transform-infrared spectroscopy (ATR–FTIR), nuclear magnetic resonance spectrometry (NMR), and gel permeation chromatography (GPC). The impact sensitivity, mechanical performance, and thermal behavior of PBFMO-b-GAP were studied by drop weight test, X-ray photoelectron spectroscopic (XPS), tensile test, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and thermal gravimetric analysis (TGA), respectively. The results demonstrated that the introduction of fluoropolymers could evidently reduce the sensitivity of GAP-based polyurethane and enhance its mechanical behavior (the tensile strength up to 5.75 MPa with a breaking elongation of 1660%). Besides, PBFMO-b-GAP exhibited excellent resistance to thermal decomposition up to 200 °C and good compatibility with Al and cyclotetramethylene tetranitramine (HMX). The thermal performance of the PBFMO-b-GAP/Al complex was investigated by a cook-off test, and the results indicated that the complex has specific reaction energy. Therefore, PBFMO-b-GAP may serve as a promising energetic binder for future propellant formulations.

scholarly journals Alkali Activation of Waste Clay Bricks: Influence of The Silica Modulus, SiO2/Na2O, H2O/Na2O Molar Ratio, and Liquid/Solid Ratio

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 383 ◽  
Author(s):  
R. A. Gado ◽  
Marek Hebda ◽  
Michal Łach ◽  
Janusz Mikuła
Keyword(s):  
Compressive Strength ◽  
Raw Material ◽  
Molar Ratio ◽  
Alkali Activation ◽  
Optimum Conditions ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Solid Ratio ◽  
Clay Bricks

This study was conducted to investigate the influence of various reaction conditions, namely the silica modulus SiO2/Na2O, H2O/Na2O molar ratio, and liquid/solid ratio on the geopolymerization reaction of the waste fired clay bricks (Grog). The starting raw material and the generated geopolymer specimens produced by different geopolymerization reaction conditions have been characterized using different techniques: X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and thermal analysis. Furthermore, physico–mechanical characterization has been carried out through the determination of bulk density, porosity, water absorption, and compressive strength for each sample at interval curing times of up to 28 days. The results indicated that the geopolymerization system of the waste fired clay bricks is influenced by the investigated reaction conditions at room temperature. The compressive strength of the geopolymer sample produced at optimum conditions increased significantly by up to 37.5 MPa, in comparison with 4.5 MPa for other conditions. Finally, an optimum recommendation and useful conclusions concerning the recycling and utilization of this waste material through the geopolymerization process are made for compatibility with construction applications.

Synthesis and Characterization of Diaminophenylindane Based Polyimides via Ester-Acid Solution Imidization

1997 ◽  
Vol 9 (3) ◽  
pp. 345-352 ◽  
Author(s):  
I V Farr ◽  
T E Glass ◽  
Q Ji ◽  
J E McGrath
Keyword(s):  
Acid Solution ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Short Term ◽  
Scanning Calorimetry ◽  
Film Forming ◽  
Solution Polycondensation

The solution polycondensation of 1-(4-aminophenyl)-5(6)-aminoindane (DAPI) with a number of commercially available dianhydrides using the two-step ester-acid solution imidization route is described. High molecular weight polyimides were successfully synthesized from a 1:1 molar ratio of dianhydride to diamine. These film-forming systems have high glass transition temperatures (331–368 °C) and very good short-term thermal stability as judged by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The fully cyclized polyimides are also highly soluble in common solvents.

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