scholarly journals Influence of Oxidation Degree on the Physicochemical Properties of Oxidized Inulin

Polymers ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1025
Author(s):  
Franklin Afinjuomo ◽  
Paris Fouladian ◽  
Thomas G. Barclay ◽  
Yunmei Song ◽  
Nikolai Petrovsky ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Functional Group ◽  
Spherical Shape ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
Oxidation Degree ◽  
Peak Intensity ◽  
13C Nuclear Magnetic Resonance ◽  
Thermal Stability Of

This paper reports the oxidation of inulin using varying ratios of sodium periodate and the characterization of the inulin polyaldehyde. The physicochemical properties of the inulin polyaldehyde (oxidized inulin) were characterized using different techniques including 1D NMR spectroscopy, 13C Nuclear magnetic resonance (NMR), Fourier transform infrared spectroscopy (FTIR), thermal gravimetric analysis (TGA), differential scanning calorimetric (DSC), ultraviolet-visible spectroscopy (UV), and scanning electron microscopy (SEM). The aldehyde peak was not very visible in the FTIR, because the aldehyde functional group exists in a masked form (hemiacetal). The thermal stability of the oxidized inulin decreased with the increasing oxidation degree. The smooth spherical shape of raw inulin was destructed due to the oxidation, as confirmed by the SEM result. The 1HNMR results show some new peaks from 4.8 to 5.0 as well as around 5.63 ppm. However, no aldehyde peak was found around 9.7 ppm. This can be attributed to the hemiacetal. The reaction of oxidized inulin with tert-butyl carbazate produced a carbazone conjugate. There was clear evidence of decreased peak intensity for the proton belonging to the hemiacetal group. This clearly shows that not all of the hemiacetal group can be reverted by carbazate. In conclusion, this work provides vital information as regards changes in the physicochemical properties of the oxidized inulin, which has direct implications when considering the further utilization of this biomaterial.

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.

scholarly journals OXIDIZED MAIZE STARCH: CHARACTERIZATION AND EFFECT OF IT ON THE BIODEGRADABLE FILMS I. CHARACTERIZATION OF MAIZE STARCH OXIDIZED BY SODIUM HYPOCHLORITE

2016 ◽  
Vol 54 (3) ◽  
pp. 347 ◽  
Author(s):  
Dao Phi Hung ◽  
Truong Thi Nam ◽  
Mac Van Phuc ◽  
Nguyen Anh Hiep ◽  
Nguyen THien Vuong ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Gelatinization Temperature ◽  
Biodegradable Films ◽  
Maize Starch ◽  
Oxidation Degree ◽  
Sem Images ◽  
Carboxyl Content ◽  
Native Starch ◽  
Significant Difference

The effects of hypochlorite level, i.e. 0.5; 1 and 2 active chlorine g/100g starch, on the structures and physicochemical properties of oxidized maize starch were investigated. The obtained results shown that oxidation degree grew up with increasing hypochlorite concentration, specially, the carboxyl content saw higher increased than the content of carbonyl. SEM images indicated that surface of oxidized maize starches were rougher than native starch. The surface of oxidized starches saw rougher with increasing hypochlorite level. However, the DSC results illustrated that there was no significant difference of gelatinization temperature between the native starch and oxidized starches.

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.

The Synthesis and Characterization of Polybenzamides Containing Siloxanes.

1988 ◽  
Vol 134 ◽  
Author(s):  
Robert J. Kumpf ◽  
Bernard Gordon
Keyword(s):  
Block Copolymer ◽  
Random Copolymer ◽  
Optical Microscope ◽  
Gravimetric Analysis ◽  
Molecular Architecture ◽  
Thermal Stabilities ◽  
Segmented Copolymers ◽  
Reflectance Ftir ◽  
Thermal Stability Of

ABSTRACTThree different kinds of siloxane-containing polybenzamide copolymers have been prepared: a series of siloxane-containing segmented copolymers; a siloxane-poly(benzamide) random copolymer; and a poly(benzamide) - poly(dimethylsiloxane) block copolymer. The structures of these copolymers were confirmed using diffuse reflectance FTIR spectroscopy. Dilute solution viscometery showed them to be high polymers. The thermal stabilities of these copolymers were studied using thermal gravimetric analysis. Incorporation of siloxane units via a phenyl link was found to not affect the inherent thermal stability of the poly(benzamide) chain. The solution phase behavior of these copolymers in DMAC/LiCl was studied using an optical microscope fitted with cross-polars. The segmented copolymers and the block copolymer exhibited lyotropic behavior, which was influenced by the amount of siloxane and the overall molecular architecture. Solutions of the random copolymer were isotropic at all concentrations studied.

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.

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.

Investigation of the internal structure, combustion, and thermal resistance of the rigid polyurethane materials reinforced with vermiculite

2020 ◽  
pp. 089270572093915
Author(s):  
İbrahim Kirbaş
Keyword(s):  
Thermal Stability ◽  
Fire Retardant ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Inorganic Mineral ◽  
Combustion Behaviors ◽  
The Cost ◽  
Thermal Stability Of

In this study, 5%, 10%, and 15% vermiculite was added to the rigid polyurethane (PU) structure as a fire retardant. The scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), limiting oxygen index, thermal gravimetric analysis, differential scanning calorimetric (DSC) curves, and combustion behavior of the composite materials were investigated. When SEM/EDS analyses were examined, it was observed that surface morphology was affected by the amount of additive material. When XRD analyses were examined, peaks appeared in three different groups. Thermogravimetric analysis was used to determine the thermal stability of PU material with the addition of vermiculite. When the DSC analysis was examined, four temperature zones were obtained. The combustion behaviors of the vermiculite added PU samples with single-flame source and the flammability classes were determined with TS EN ISO 11925-2 standard. It can be said that the usage of inorganic mineral, which is harmless to the environment, can enhance the thermal stability of the material and also reduce the cost of production.

scholarly journals Cashew Nut Shell Liquid (CNSL) Based Bio-Derived Resin And Composites for Advanced Structural, Automotive, Electronic Packaging and Medical applications- A Review.

2020 ◽  
Vol 1 (2) ◽  
Author(s):  
Padmanabhan Krishnan
Keyword(s):  
Natural Resources ◽  
Electronic Packaging ◽  
Thermo Gravimetric Analysis ◽  
Petroleum Engineering ◽  
Differential Scanning Calorimetric ◽  
Gravimetric Analysis ◽  
Cashew Nut Shell Liquid ◽  
Cashew Nut ◽  
Cashew Nut Shell

As India is a world class producer of sugarcane, sugar beet, other tubers like potato and vegetables with  starch, cashew and badam, castor oil and soybean, the quantum of bio resins and bio plastics that can be produced from these conventional, organic and genetically modified plants is immense. As on date, advanced and state of the art plastics and composites are being used in many applications as there is no incentive for farmers to produce plants and vegetables for the plastics and resins market exclusively. The use of advanced composites in varied applications escalates costs and shifts the material consumption that would deplete the natural resources, through  excessive usage at one end and lack of demand for natural resources at the other end as bio derived composites become under-utilized. This review paper attempts to project the actual possibilities of the bio resin and bio plastic market in this country and provides the knowhow for the production of  bio-phenolic cashew nut shell resin which are more than a substitute for the synthetically produced epoxies. Their true potentialities in composites product applications involving structural, thermal, electronic, pharmaceutical and petroleum engineering markets is discussed in this paper. A novel working model with an economically feasible option is also provided for those concerned about their safe disposal, recycling, reuse and conversion into useable fuel with virtually no impact to the environment. Cashew Nut Shell Liquid (CNSL) is an abundant natural source for synthesizing phenolic compounds. The excellent monomer, Cardanol is isolated from CNSL for polymer production. These are polymerized with aldehydes and acids at a particular mole fraction in the presence of catalysts like alkalis to convert into rigid resins. Differential Scanning Calorimetric (DSC) and Thermo Gravimetric Analysis (TGA) were studied for the thermal characterization of the synthesized CNSL Resins. Characterization of the synthesized resins was also carried out with respect to the evaluated mechanical properties such as hardness, strength, elastic modulus and fracture toughness. The synthesized CNSL resins yielded many interesting compositions with varied properties increasing the possibilities of various resin formulations which could be used for composites applications in vibrational damping. The electronic packaging applications of nano-composites with high dielectric strength produced with the   CNSL matrix are also highlighted.

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.

scholarly journals Synthesis of microcrystalline cellulose from pretreated cotton obtained from Bombax ceiba L. and its characterization

2015 ◽  
Vol 50 (3) ◽  
pp. 199-204 ◽  
Author(s):  
SM Haque ◽  
AA Chowdhury ◽  
AA Rana ◽  
SM Masum ◽  
T Ferdous ◽  
...  
Keyword(s):  
Acid Hydrolysis ◽  
Microcrystalline Cellulose ◽  
Cellulose Content ◽  
Gravimetric Analysis ◽  
Particle Characterization ◽  
Polymeric Form ◽  
Commercial Grade ◽  
Hausner Ratio ◽  
Thermal Stability Of

Microcrystalline cellulose (MCC) is an important ingredient in pharmaceutical, food, cosmetic and other industries. Microcrystalline cellulose was synthesized from the alpha cellulose content of pretreated cotton, Bombax ceiba L. by hydrochloric acid hydrolysis. The prepared microcrystalline cellulose was characterized by determining some physicochemical properties such as pH, angle of response, Carr’s index, Hausner ratio, moisture content etc and compared with commercial-grade microcrystalline cellulose that is used in pharmaceutical industry as excipient. Scanning electron microscope (SEM) and FTIR data represented the structure and particle characterization of sample. Thermal gravimetric analysis (TGA) showed the thermal stability of the sample. The results showed that the yield of microcrystalline cellulose was about 85% and compared favorably with the commercial grade microcrystalline cellulose as well as conformed official specifications for microcrystalline cellulose in British Pharmacopeia. It was also found that the duration of acid hydrolysis affected the polymeric form of the processed alpha cellulose.Bangladesh J. Sci. Ind. Res. 50(3), 199-204, 2015

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