Synthesis and characterization of diaminomaleonitrile-functionalized polystyrene grafts for application in pervaporation separation

2008 ◽  
Vol 62 (4) ◽  
Author(s):  
Hamada Abdel-Razik
Keyword(s):  
Chemical Structure ◽  
Thermal Characteristics ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Optimum Conditions ◽  
Scanning Calorimetry ◽  
Phenol Water ◽  
Pervaporation Separation ◽  
Thermal Stability Of

AbstractSynthesis, characterization and application of diaminomaleonitrile (DAMN)-functionalized polystyrene grafts were studied. Dibenzoyle peroxide (BP) was used as an initiator. Optimum conditions for grafting were found to be c(DAMN) = 0.5 M, c(BP) = 0.016 M, θ = 85 °C and t = 4 h. Water uptake of the polystyrene graft membranes was found to increase with the increase of the grafting yield. The chemical structure, thermal characteristics and thermal stability of the obtained membranes were investigated by means of FTIR spectroscopy, differential scanning calorimetry, and thermal gravimetric analysis. Polystyrene graft membrane with the degree of grafting of up to 96 % was found to be useful for the pervaporation separation of phenol/water mixtures.

Preparation and Characterization of Polymer/Multi-Walled Carbon Nanotube Nanocomposites

2008 ◽  
Vol 140 ◽  
pp. 97-102 ◽  
Author(s):  
M. Sarah Mohlala ◽  
Suprakas Sinha Ray
Keyword(s):  
Gravimetric Analysis ◽  
Melt Blending ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Multiwalled Carbon ◽  
Nanostructured Composite ◽  
Transmission Electron ◽  
Multi Walled Carbon Nanotube ◽  
Thermal Stability Of

This paper describes the preparation, characterization and properties of nanostructured composite materials based on poly(butylene adipate-co-polycaprolactam) (PBA-co-PCL)/multiwalled carbon nanotubes (MWCNTs) and polycaprolactone (PCL)/MWCNTs. The polymer/MWCNTs nanocomposites were prepared by mixing the polymers with various amounts of MWCNTs using both solution and melt blending processes. The dispersion of MWCNTs into the polymer matrix was analyzed by transmission electron microscopy (TEM) and the thermal stability of the nanocomposites was studied by thermal gravimetric analysis (TGA). Differential scanning calorimetry (DSC) was used to study the crystallization and melting behaviour of the polymer matrices containing the MWCNTs.

scholarly journals The Preparation and Characterization of Chitosan / Poly (Vinyl Alcohol) Blended Films

2010 ◽  
Vol 7 (4) ◽  
pp. 1212-1219 ◽  
Author(s):  
Esam A. El-Hefian ◽  
Mohamed Mahmoud Nasef ◽  
Abdul Hamid Yahaya
Keyword(s):  
Smooth Surface ◽  
Chemical Structure ◽  
Poly Vinyl Alcohol ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Blend Films ◽  
Main Component ◽  
Thermal Stability Of ◽  
Scanning Electron

In this study, chitosan and PVA were blended at different proportions (considering chitosan as the main component) in solution forms. The chemical structure and the morphology of the obtained blend films were investigated using FTIR and field emission scanning electron microscope (FESEM). The thermal stability of the blend films were also studied using thermal gravimetric analysis (TGA). Our results showed that chitosan and PVA form a compatible blend and their films displayed homogenous and smooth surface properties compared to their individual pure components. The blending of PVA with chitosan at all proportions was found to highly enhance the swelling of the obtained films compared to that of pure chitosan one.

Systematic Characterization of Different Quaternary Ammonium Salts to be Used in Organoclays

2012 ◽  
Vol 727-728 ◽  
pp. 1552-1556
Author(s):  
Renata Barbosa ◽  
Dayanne Diniz Souza ◽  
Edcleide Maria Araújo ◽  
Tomás Jefférson Alves de Mélo
Keyword(s):  
Thermal Stability ◽  
Quaternary Ammonium ◽  
Chemical Structure ◽  
Quaternary Ammonium Salts ◽  
Ammonium Salts ◽  
Degradation Mechanisms ◽  
Scanning Calorimetry ◽  
Higher Temperature ◽  
Thermal Stability Of

Studies of degradation have verified that the decomposition of some quaternary ammonium salts can begin to be significant at the temperature of about 180 ° C and like most thermoplastics are processed at least around this temperature, the thermal stability of the salt in clay should always be considered. Some salts are more stable than others, being necessary to study the degradation mechanisms of each case. In this work, four quaternary ammonium salts were characterized by differential scanning calorimetry (DSC) and thermogravimetry (TG). The results of DSC and TG showed that the salts based chloride (Cl-) anion begin to degrade at similar temperatures, while the salt based bromide (Br-) anion degrades at higher temperature. Subsequently, a quaternary ammonium salt was chosen to be used in organoclays, depending on its chemical structure and its thermal behavior.

Synthesis and thermal stability studies of polyaniline/silver nanocomposite based on reduction of silver ions using polyaniline

2011 ◽  
Vol 23 (7) ◽  
pp. 513-517 ◽  
Author(s):  
Mohsen Ghorbani ◽  
Mohammad Soleimani Lashkenari ◽  
Hossein Eisazadeh
Keyword(s):  
Thermal Stability ◽  
Chemical Structure ◽  
Aqueous Media ◽  
Silver Ions ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Stability Studies ◽  
Scanning Calorimetry ◽  
Chemical Polymerization ◽  
Silver Nanocomposite

This study investigated the preparation and properties of polyaniline/silver (PAn/Ag2O) nanocomposite in aqueous media by chemical polymerization of aniline in the presence of ammonium peroxydisulphate as an oxidant. The products were investigated in terms of morphology, chemical structure, thermal stability and thermal degradation using scanning electron microscopy, Fourier transform infrared, thermal gravimetric analysis and differential scanning calorimetry, respectively. The results indicated that the properties of products were dependent on the nanocomposite structure.

scholarly journals Characterization of polydimethylsiloxane rubber upon photochemical, thermal, salt-fog ageings and exposure to acid vapours

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
F. Delor-Jestin ◽  
N. S. Tomer ◽  
R.P. Singh ◽  
J. Lacoste
Keyword(s):  
Ir Spectroscopy ◽  
Chemical Structure ◽  
Mesh Size ◽  
Cross Linking ◽  
Scanning Calorimetry ◽  
New Knowledge ◽  
Salt Fog ◽  
Complementary Analysis ◽  
Thermal Stability Of

AbstractThe changes in the chemical structure and the physical properties of a filled crosslinked polydimethylsiloxane rubber were monitored as a function of various ageing factors. The variables included photochemical, thermal, salt-fog ageings and exposure to acid vapours. Unaged and aged samples were studied by IR spectroscopy, hardness measurements, Differential Scanning Calorimetry (DSC) and thermogravimetric analysis (TGA) coupled with IR spectroscopy. No significant oxidation was detected after all ageings, except for nitric acid treatment. The presence of aluminium trihydrate was clearly identified as responsible for the observed chemical changes. Then an important vulnerability of this filled silicone rubber towards the cross-linking reactions provoked by usual ageings was also detected. The DSC-thermoporosimetry measurements of the mesh size distribution gave a comparison of cross-linking densities for each ageing. The complementary analysis with TGAIR allowed us to differenciate the thermal stability of the formulation after various ageings and to acquire new knowledge about thermal decomposition.

Experimental Investigation of Kevlar KM2Plus Nano-Reinforced Laminated Composite Thermo-Mechanical Properties

2016 ◽  
Author(s):  
Abdel-Hamid I. Mourad ◽  
Omar G. Ayad ◽  
Ashfakur Rahman ◽  
Ali Hilal-Alnaqbi ◽  
Basim I. Abu-Jdayil
Keyword(s):  
Mechanical Properties ◽  
Thermo Gravimetric Analysis ◽  
Laminated Composite ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Three Point Bending ◽  
Multi Walled Carbon Nanotube ◽  
Thermal Stability Of

This work is concerned with the synthesis and characterization of Multi-Walled Carbon Nanotube (MWCNT) reinforced Kevlar KM2Plus composites with various MWCNT contents (0.2, 0.3, 0.4, 0.5, 0.6, and 0.8 wt. %), by the wet lay-up technique. These samples were experimentally investigated for their thermo-mechanical properties using Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry (DSC), tensile testing and three-point bending techniques. The mechanical properties showed remarkable improvement with increasing MWCNT wt.% up to certain content. The results revealed that the addition of MWCNT fillers has no significant effect on the thermal stability of the composites.

Synthesis and characterization of poly(arylene ether)s and poly(arylene ether imidazole)s

1995 ◽  
Vol 7 (1) ◽  
pp. 69-79 ◽  
Author(s):  
P R McDaniel ◽  
R A Orwoll ◽  
J W Connell
Keyword(s):  
Epoxy Resins ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Structure Property ◽  
Neat Resin ◽  
Scanning Calorimetry ◽  
High Toughness ◽  
Arylene Ether ◽  
Structure Property Relationship

Poly(arylene ether)s, poly(arylene ether imidazole)s and poly(arylene ether coimidazole)s are under investigation as part of a structure/property relationship study. The objective of this study is to identify polymers or copolymers with an attractive combination of properties for use as toughening agents for epoxies. The copolymers are being studied as possible toughness modifiers for epoxy resins because of their high glass transition temperatures, their high toughness and the ability of the active hydrogen on the imidazole moiety to react with the oxirane ring of epoxies. Homopolymers and copolymers were characterized by differential scanning calorimetry, thermal gravimetric analysis, thin-film tensile properties and neat resin flexural and toughness properties.

scholarly journals Preparation and Characterization of Chitosan/Agar Blended Films: Part 2. Thermal, Mechanical, and Surface Properties

2012 ◽  
Vol 9 (2) ◽  
pp. 510-516 ◽  
Author(s):  
Esam A. Elhefian ◽  
Mohamed Mahmoud Nasef ◽  
Abdul Hamid Yahaya
Keyword(s):  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Water Contact ◽  
Elongation At Break ◽  
Angle Measurements ◽  
Static Water Contact Angle ◽  
Contact Angle Measurements ◽  
Static Water ◽  
Thermal Stability Of

Chitosan/agar (CS/AG) films were prepared by blending different proportions of chitosan and agar (considering chitosan as the major component) in solution forms. The thermal stability of the blended films was studied using thermal gravimetric analysis (TGA). It was revealed that chitosan and agar form a compatible blend. Studying the mechanical properties of the films showed a decrease in the tensile strength and elongation at break with increasing agar content. Blending of agar with chitosan at all proportions was found to form hydrogel films with enhanced swelling compared to the pure chitosan one. Static water contact angle measurements confirmed the increasing affinity of the blended films towards water suggesting that blending of agar with chitosan improves the wettability of the obtained films.

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.

Effect of chemical treatment on thermal properties of bagasse fiber-reinforced epoxy composite

2017 ◽  
Vol 24 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Varun Mittal ◽  
Shishir Sinha
Keyword(s):  
Thermal Stability ◽  
Thermal Properties ◽  
Chemical Treatment ◽  
Epoxy Composite ◽  
Gravimetric Analysis ◽  
Thermal Gravimetric ◽  
Scanning Calorimetry ◽  
Chemical Treatments ◽  
Bagasse Fiber ◽  
Thermal Stability Of

AbstractThe present paper deals with a study of the thermal properties of bagasse fiber (BF)-reinforced epoxy composites. BFs are subjected to untreated and chemical treatments with 1% sodium hydroxide followed by 1% acrylic acid at ambient temperature before the composites are made. The thermal stability of the components was studied by thermogravimetric analysis and differential scanning calorimetry, as well as by differential thermal gravimetric analysis. Thermal analysis results of untreated BF-reinforced epoxy composite were compared with treated BF-reinforced epoxy composite. The chemical treatment of BF induces reasonable changes in the thermal stability of the polymer composites.

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