Changes of Corn Flour by Different Treatments

2012 ◽  
Vol 554-556 ◽  
pp. 1017-1020
Author(s):  
De Jing Wang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Gel Permeation Chromatography ◽  
Bimodal Distribution ◽  
Wet Milling ◽  
Corn Flour ◽  
Scanning Calorimetry ◽  
Gel Permeation ◽  
Chain Lengths

The properties of corn flour prepared by fermenting, wet-milling and extruding were investigated. The results showed that RVA parameters of the corn flours by fermenting compared with wet-milling decreased but enthalpies slightly increased. Extruded samples had no peak (RVA) and no differential scanning calorimetry (DSC) endotherm. In fermenting and wet milling starches a bimodal distribution of chain lengths( fractionⅠand Ⅱ) were found by gel permeation chromatography but extruded starches only one fraction.

scholarly journals A New Method for Synthesis of Poly(2,6-dimethyl-1,4-phenylene oxide) and Poly(2,6-diphenyl-1,4-phenyl oxide)

2013 ◽  
Vol 2013 ◽  
pp. 1-4
Author(s):  
Naser M. Al Andis
Keyword(s):  
Differential Scanning Calorimetry ◽  
Nmr Spectroscopy ◽  
Microwave Heating ◽  
Molar Mass ◽  
Gel Permeation Chromatography ◽  
High Yield ◽  
Scanning Calorimetry ◽  
Phenylene Oxide ◽  
Gel Permeation ◽  
Amine Complex

The polymerization of two monomers 2,6-dimethylphenol and 2,6-diphenylphenol was carried out by an oxidative route in the presence of Cu(I) as a catalyst and amine complex as a solvent assisted by microwave heating. The synthesized polymers were characterized by NMR spectroscopy, differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). It was observed that this process of polymerization gives high yield (98 wt%) of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and poly(2,6-diphenyl-1,4-phenylene oxide) (PPPO) with a molar mass of 1180 (M¯n), 1400 (M¯w) and 28000 (M¯n), 46500 (M¯w) gm/mol, respectively. A negligible amount of diphenoquinone was also observed and its dispersity was rather moderate, 1.17 and 1.68, respectively.

scholarly journals 1-n-Butyl-3-methylimidazolium-2-carboxylate: a versatile precatalyst for the ring-opening polymerization of ε-caprolactone and rac-lactide under solvent-free conditions

2013 ◽  
Vol 9 ◽  
pp. 647-654 ◽  
Author(s):  
Astrid Hoppe ◽  
Faten Sadaka ◽  
Claire-Hélène Brachais ◽  
Gilles Boni ◽  
Jean-Pierre Couvercelle ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Ring Opening ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Solvent Free ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Solvent Free Conditions ◽  
Gel Permeation

The ring-opening polymerization of ε-caprolactone (ε-CL) and rac-lactide (rac-LA) under solvent-free conditions and using 1-n-butyl-3-methylimidazolium-2-carboxylate (BMIM-2-CO2) as precatalyst is described. Linear and star-branched polyesters were synthesized by successive use of benzyl alcohol, ethylene glycol, glycerol and pentaerythritol as initiator alcohols, and the products were fully characterized by 1H and 13C{1H} NMR spectroscopy, gel permeation chromatography (GPC), and differential scanning calorimetry (DSC). BMIM-2-CO2 acts as an N-heterocyclic carbene precursor, resulting from in situ decarboxylation, either by heating under vacuo (method A) or by addition of NaBPh4 (method B). Possible catalytic and deactivation mechanisms are proposed.

The Preparation and Characterization of Polycaprolactone Elastomer Polymer

2013 ◽  
Vol 641-642 ◽  
pp. 201-205
Author(s):  
Hong Su ◽  
Li Mei Guo ◽  
Lian Yong Wang
Keyword(s):  
Molecular Structure ◽  
Mechanical Property ◽  
Molecular Weight ◽  
Differential Scanning Calorimetry ◽  
Citric Acid ◽  
Gel Permeation Chromatography ◽  
Scanning Calorimetry ◽  
Elastomeric Material ◽  
Gel Permeation

polycaprolactone diols (MW=540, 1000, 2000) and citric acid were used as monomers, polycaprolactone-citric acid preformed polymer was preparated firstly by the heating polycondensation, then the preformed polymer was heated and cross-linked to obtain biodegradable elastomeric material. The molecular structure and Molecular weight was proved respectively by 1-HNMR and Gel Permeation Chromatography (GPC). The shape and glass transition temperature (Tg) of polycaprolactone-citric acid polymer was certified by differential scanning calorimetry(DSC). The hydrophilicity of the polymer was evaluated by its contact angle. The polymer’s mechanical property and degradation speed was also investigated.

Urea-formaldehyde (UF) resins prepared by means of the aqueous phase of the catalytic pyrolysis of European beech wood. COST Action FP1105

Holzforschung ◽  
2016 ◽  
Vol 70 (12) ◽  
pp. 1139-1145 ◽  
Author(s):  
Electra Papadopoulou ◽  
Sotiris Kountouras ◽  
Zoe Nikolaidou ◽  
Konstantinos Chrissafis ◽  
Chrysoula Michailof ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Aqueous Phase ◽  
Catalytic Pyrolysis ◽  
Urea Formaldehyde ◽  
Beech Wood ◽  
Gel Permeation Chromatography ◽  
European Beech ◽  
Thickness Swelling ◽  
Scanning Calorimetry ◽  
Gel Permeation

Abstract The aqueous phase resulting from the catalytic pyrolysis (AQcatPy) of biomass has been successfully applied for acidification of urea-formaldehyde (UF) resins. The resins were synthesized at a laboratory scale and characterized by gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The bonding ability of the resins was tested through the preparation of particle boards (PBs). It was found that the UF resins prepared with AQcatPy as acidification medium have a similar performance to typical UF resins, where conventional chemicals like formic acid (FA) or acetic acid (AA) serve for pH adjustments. The new resins give PBs with somewhat improved thickness swelling (TS) values, while all other properties are at the same level.

Photosensitive polyrotaxanes: New comb-like polymethacrylamides containing 1,3- diphenyl-2-propen-1-one (chalcone) functions and noncovalently bound cyclodextrin in the side-chains

e-Polymers ◽  
2002 ◽  
Vol 2 (1) ◽  
Author(s):  
Christian Goretzki ◽  
Helmut Ritter
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Methyl Methacrylate ◽  
Gel Permeation Chromatography ◽  
Side Chain ◽  
Scanning Calorimetry ◽  
Chloride Dihydrate ◽  
Retarding Effect ◽  
Gel Permeation ◽  
Tetrahydrofuran Solution

AbstractThe synthesis and free radical polymerization of a methacrylamide monomer, 5, bearing non-covalently attached cyclodextrins and the chalcone function with a barrier group, is described. The first step of preparation of the monomer was the condensation of 4-(N-methacryloyl-6-aminohexanoylamino)- acetophenone, 1, with 4-nitrobenzaldehyde. The resulting 1-(N-methacryloyl-6- aminohexanoyl-4-aminophenyl)-3-(4-nitrophenyl)-2-propen-1-one, 2, was reduced with tin(II) chloride dihydrate to the corresponding 1-(N-methacryloyl-6-aminohexanoyl- 4-aminophenyl)-3-(4-aminophenyl)-2-propen-1-one, 3. After this, the aminochalcone was condensed with a barrier group, triphenylacetyl chloride, yielding 1-(N-methacryloyl-6-aminohexanoyl-4-aminophenyl)-3-(N’-triphenylacetyl- 4-aminophenyl)-2-propen-1-one, 4. Monomer 4 was copolymerized with methyl methacrylate to the model polymer poly[4-co-methyl methacrylate], 6, and also complexed with dimethylated β-cyclodextrin to the semi-rotaxane (4 / 2,6-Me2-β- CD) 5, which was copolymerized with methyl methacrylate, yielding a polyrotaxane (5-co-methyl methacrylate) 7, containing a cyclodextrin ring in the side-chain. The semi-rotaxane 5 and both copolymers 6 and 7 were characterized spectroscopically and also by means of differential scanning calorimetry, gel permeation chromatography and thermogravimetrical analysis, and - in the case of 5 - by mass spectrometry. Furthermore, the UV-induced E/Z-isomerization of both polymers 6 and 7 was examined in tetrahydrofuran solution. A retarding effect of the noncovalently attached cyclodextrin was finally detected.

New Arylidene—Siloxane Polyesters

2003 ◽  
Vol 15 (3) ◽  
pp. 231-242 ◽  
Author(s):  
Carmen Racles ◽  
Vasile Cozan ◽  
Maria Cazacu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Nmr Spectroscopy ◽  
Liquid Crystalline ◽  
Gel Permeation Chromatography ◽  
Polymer Structure ◽  
Scanning Calorimetry ◽  
Polarized Optical Microscopy ◽  
H Nmr ◽  
Gel Permeation ◽  
Thermotropic Liquid Crystalline Behavior

New siloxane-containing polyesters with arylidene mesogenic moieties were prepared by copolycondensation reactions between bis(hydroxybuthyl)siloxanes, 2,6-bis(4-hydroxybenzylidene)cyclohexanone, and diacid chlorides such as sebacoyl and terephthaloyl. The polymer structure was confirmed by IR and 1H-NMR spectroscopy. They were characterized by gel permeation chromatography and ultraviolet analyses. The thermotropic liquid crystalline behavior was investigated by differential scanning calorimetry and polarized optical microscopy.

Synthesis and characterization of 4-chloromethylstyrene polymers containing bulky organosilicon groups

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Kazem Dindar Safa ◽  
Mirzaagha Babazadeh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Gel Permeation Chromatography ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Gel Permeation ◽  
Covalently Linked ◽  
C Nmr

Abstract The homopolymer of 4-chloromethylstyrene and its copolymers with styrene (in 1:3 and 1:1 mole ratio) were synthesized by bulk and solution freeradical polymerisations, respectively, at 70±1°C using α,α'-azoisobutyronitrile as an initiator. Highly sterically hindered tris(trimethylsilyl)methyl (Tsi) substituents were then covalently linked to the obtained homopolymer and copolymers. The polymers were characterized by IR, 1H NMR and 13C NMR, differential scanning calorimetry (DSC) and gel permeation chromatography. DSC showed that incorporation of Tsi substituents in the side chains of homopolymer and copolymers increases the rigidity of the polymers and, subsequently, their glass transition temperature.

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