scholarly journals Thermal Degradation Studies of Terpolymer Derived from 2-Aminothiophenol, Hexamethylenediamine, and Formaldehyde

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
P. U. Belsare ◽  
A. B. Zade ◽  
P. P. Kalbende ◽  
M. S. Dhore
Keyword(s):  
Activation Energy ◽  
Average Molecular Weight ◽  
Conductometric Titration ◽  
Frequency Factor ◽  
Characteristic Functions ◽  
Spectral Techniques ◽  
H Nmr ◽  
Ft Ir ◽  
Relative Thermal Stability

Terpolymer (2-ATPHMDAF-I) has been synthesized by the condensation of 2-aminothiophenol and hexamethylenediamine with formaldehyde in the presence of 2 M hydrochloric acid as a catalyst with 1 : 1 : 2 molar proportion of reacting monomers. The structure of newly synthesized terpolymer has been elucidated and confirmed on the basis of elemental analysis and various spectral techniques, that is, UV-visible, FT-IR, and 1H-NMR spectroscopy. Number average molecular weight (Mn¯) has been determined by conductometric titration in nonaqueous medium. The viscosity measurements in dimethyl sulfoxide (DMSO) have been carried out to ascertain the characteristic functions and constants. The studies have been further extended to nonisothermal thermogravimetric analysis for determination of their mode of decomposition and relative thermal stability. Activation energy Ea, order of reaction (n), and frequency factor (z) were calculated by Friedman, Chang, Sharp-Wentworth and Freeman-Carroll methods. Activation energy calculated by Friedman and Chang methods are in close agreement with each other while the results obtained from Freeman-Carroll and Sharp-Wentworth’s methods are found to be in a similar order.

scholarly journals Study of Non-Isothermal Decomposition and Kinetic Analysis of 2,4-Dihydroxybenzoic Acid- Melamine-Formaldehyde Copolymer

2010 ◽  
Vol 7 (3) ◽  
pp. 1101-1107 ◽  
Author(s):  
S. S. Butoliya ◽  
W. B. Gurnule ◽  
A. B. Zade
Keyword(s):  
Kinetic Parameters ◽  
Average Molecular Weight ◽  
Acid Catalyst ◽  
Conductometric Titration ◽  
Frequency Factor ◽  
Entropy Change ◽  
Dihydroxybenzoic Acid ◽  
H Nmr ◽  
Uv Visible

A copolymer (2,4-DHBAMF) synthesized by the condensation of 2,4-dihydroxybenzoic acid and melamine with formaldehyde in the presence of acid catalyst using varied molar proportions of the reactants. A composition of the copolymer has been determined by elemental analysis. The number average molecular weight has been determined by conductometric titration in non-aqueous medium. The copolymer has been characterized by UV-Visible, IR and1H NMR spectral analysis. Thermogravimetric analysis was carried out to study the decomposition and various kinetic parameters. Freeman Carroll and Sharp Wentworth methods have been applied for the calculation of kinetic parameters while the data from Freeman Carroll method have been used to determine various thermodynamic parameters such as order of reaction, energy of activation, frequency factor, entropy change, free energy change and apparent entropy change. The results indicate that given copolymer have potential as matrix resin for long term applications at temperature up to 350°C.

scholarly journals Preparation, Characterization, and Thermal Degradation Studies ofp-Nitrophenol-Based Copolymer

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Pawan P. Kalbende ◽  
Mangesh V. Tarase ◽  
Anil B. Zade
Keyword(s):  
Thermal Degradation ◽  
Thermal Activation ◽  
Frequency Factor ◽  
Spectral Studies ◽  
H Nmr ◽  
Degradation Pattern ◽  
Degradation Step ◽  
Ft Ir ◽  
Uv Visible ◽  
Most Probable Structure

Polycondensation reaction was employed to synthesize a new copolymer resin (p-NP-4,4′-MDA-F) from p-nitrophenol (p-NP) and 4,4′-methylene dianiline (4,4′-MDA) with formaldehyde (F) in presence of 2 M hydrochloric acid as a catalyst at130±1°C. The resin was characterized by elemental analysis and spectral studies such as UV-visible, FT-IR, and1H-NMR spectra which were used to confine the most probable structure of synthesized copolymer. Thermal degradation pattern and kinetics have been investigated by thermogravimetric analysis. Thermal degradation curve have been studied with minute detail for each degradation step. Friedman, Chang, Sharp-Wentworth, Freeman-Carroll, and Coat-Redfern methods have been implemented in order to compute the kinetic parameters, that is, thermal activation energy (Ea), order of reaction (n), and frequency factor (z).

Cationic copolymerization of 1,3-pentadiene with α-pinene

2014 ◽  
Vol 34 (7) ◽  
pp. 583-589 ◽  
Author(s):  
Ai-Yuan Li ◽  
Xiang-Dong Sun ◽  
Hui-Bo Zhang ◽  
Yong-Chun Zhang ◽  
Bin Wang ◽  
...  
Keyword(s):  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Polymerization Temperature ◽  
Scanning Calorimetry ◽  
Gardner Color ◽  
H Nmr ◽  
Cationic Copolymerization ◽  
Ft Ir ◽  
Better Than ◽  
C Nmr

Abstract The cationic copolymerization of 1,3-pentadiene (PD) with α-pinene (AP) initiated by aluminum trichloride (AlCl3) was carried out in N-pentane solvent. The effects of the polymerization temperature and the comonomer composition on the yield of the copolymer, softening point, Gardner color scale and number-average molecular weight (Mn) are discussed. The performance of the copolymer was better than that of AP homopolymer (PAP) and PD homopolymer (PPD). The structure of the copolymer was characterized by Fourier transform infrared spectroscopy (FT-IR), 1H-nuclear magnetic resonance (1H-NMR), 13C-NMR, differential scanning calorimetry (DSC) and gel permeation chromatography (GPC). In addition, the reactivity ratios for AP (M1) and PD (M2) determined by the Kelen-Tudos method from low-conversion data are r1=0.58 and r2=5.92, respectively.

scholarly journals Non-isothermal Kinetic Study ofp-Cresol-Dithiooxamide-Formaldehyde Terpolymer

2010 ◽  
Vol 7 (4) ◽  
pp. 1380-1390 ◽  
Author(s):  
W. B. Gurnule ◽  
S. S. Katkamwar
Keyword(s):  
Activation Energy ◽  
Thermal Stability ◽  
Thermal Degradation ◽  
Kinetic Study ◽  
Elemental Analysis ◽  
Frequency Factor ◽  
Entropy Change ◽  
H Nmr ◽  
Uv Visible ◽  
Isothermal Kinetic

Terpolymer (p-CDF) has been prepared by using the monomerp-cresol, dithiooxanude and formaldehyde in 1:1:2 molar proportions. The structure ofp-CDF terpolymer has been elucidated on the basis of elemental analysis and various physicochemical technique like UV-visible, FTIR,1H NMR and TG analysis. Detailed thermal degradation curve is discussed which shows four steps decomposition. The activation energy (Ea) and thermal stability calculated by using the Sharp Wentworth, Frceman-Carroll methods. Thermodynamics parameters such as entropy change (ΔS), apparent entropy change (S*) and frequency factor (z) have also been evaluated on the basis of the data of Freeman-Carroll method. The order of reaction (n) is found to be 1.05.

Determination of Molecular Weight and Structure Characterization of Canna Amylose Purified Using the Method of n-Butanol Recrystallization

2012 ◽  
Vol 554-556 ◽  
pp. 1216-1222
Author(s):  
Hai Xin Shi ◽  
Yan Zhen Yin ◽  
Xiao Xi Hu ◽  
Shu Fei Jiao
Keyword(s):  
Molecular Weight ◽  
Average Molecular Weight ◽  
Structure Characterization ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Granule Surface ◽  
Chemical Groups ◽  
Ubbelohde Viscometer

The canna amylose (CAM) was separated from canna starch grown in China and purified both using the method of n-butanol recrystallization. The purity, morphology, spectral properties and molecular weight of CAM were characterized by ultraviolet and visible spectrophotometer (UV/Vis), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscope (FT-IR) and Ubbelohde viscometer. Maximum absorption wavelength of the purified CAM (635－638 nm) and it’s blue values (BV) (1.167 ± 0.209) prove that the purification of the CAM by n-butanol recrystallization was successfully carried out. The SEM results show that CAM granule surface become rougher and the CAM granule size become smaller than that of canna starch. The XRD results suggest that most of CAM granule is amorphous. And the FT-IR results show that the basic chemical groups of canna starch are also presented in CAM. However, the amorphous area of CAM is increased. The intrinsic viscosity and viscosity-average molecular weight of CAM is 78.5 mL/g and 1.65×105, respectively.

scholarly journals The Optimum Reaction Time, Activation Energy and Frequency Factor of Methyl Ricinoleate Nitration

2013 ◽  
Vol 13 (1) ◽  
pp. 36-40 ◽  
Author(s):  
Abdullah Abdullah ◽  
Triyono Triyono ◽  
Wega Trisunaryanti ◽  
Winarto Haryadi
Keyword(s):  
Activation Energy ◽  
Reaction Time ◽  
Methyl Ricinoleate ◽  
Frequency Factor ◽  
Optimum Reaction

Determination of the optimum reaction time, activation energy (Ea) and frequency factor (A) of methyl ricinoleate nitration has been done. The nitration was conducted with the mole ratio of methyl ricinoleate to HNO3 of 1:15. The reaction was conducted at temperatures of 29 and 64 °C with a variation of reaction time for 10, 20, 30, 60, 90, 120, and 150 min. Determination of activation energy and frequency factor was performed in a temperature of 29, 33, 38, 44, 49, 57 and 64 °C. The results showed that the optimum reaction time is 90 min. The activation energy (Ea) and frequency factor (A) was 44.5 kJ/mol and 4.780 x 103 sec-1, respectively.

Thermal Oligomerisation of Cardanol

e-Polymers ◽  
2006 ◽  
Vol 6 (1) ◽  
Author(s):  
Francisco Helder A. Rodrigues ◽  
José Roberto R. Souza ◽  
Francisco Célio F. França ◽  
Nágila M. P. S. Ricardo ◽  
Judith P. A. Feitosa
Keyword(s):  
Activation Energy ◽  
Double Bond ◽  
Average Molecular Weight ◽  
Hydrocarbon Chain ◽  
Relative Mass ◽  
Cashew Nut Shell Liquid ◽  
Flow Activation Energy ◽  
H Nmr ◽  
Cashew Nut ◽  
Flow Activation

AbstractCardanol was extracted from technical Cashew Nut Shell Liquid (CNSL), a naturally occurring meta-substituted long chain phenol and oligomerized by heating at 140 °C. Products were characterized by rheology, infrared and 1H NMR spectroscopy and thermogravimetric analysis (TGA). Increase in viscosity and the flow activation energy was found with increasing time of heating. The relative absorbance of double bond of the hydrocarbon chain decreased with time of heating and indicated that the oligomerization is taking place through the unsaturation of the side chain. Decrease in internal double bond as well as in vinyl bond, observed by 1H NMR, pointed out to the participation of these two kinds of unsaturation as well as monoene, diene and triene. The oligomerization is a slow process. With 40 h of heating, the average molecular weight increases only by 46%. Great differences were found in TGA curves of cardanol with different times of oligomerization. Thermal stability increases with time of heating. The degree of oligomerization could be determined from relative mass loss of the first event of TG, or from flow activation energy.

scholarly journals Synthesis, Characterization and Thermal Analysis of a New Acetic Acid (2-Hydroxy-benzylidene)-hydrazide and its Complexes with Hg(II) and Pd(II)

2011 ◽  
Vol 8 (s1) ◽  
pp. S13-S18
Author(s):  
Hajar Sahebalzamani ◽  
Shahriare Ghammamy ◽  
Shaghayegh Dexhkam ◽  
Alireza Hemati Moghadam ◽  
Farhod Siavoshifar
Keyword(s):  
Thermal Analysis ◽  
Thermal Decomposition ◽  
Acetic Acid ◽  
Thermal Properties ◽  
Nmr Spectroscopy ◽  
Coordination Mode ◽  
Spectral Techniques ◽  
H Nmr ◽  
Multi Stage ◽  
Ft Ir

The new complexes have been synthesized by the reaction of Hg(II) and Pd(II) with acetic acid(2-hydroxy-benzylidene)- hydrazide (L). These new complexes were characterized by elemental analysis, IR, H NMR spectroscopy and UV spectral techniques. The changes observed between the FT-IR, H NMR and UV-Vis spectra of the ligands and of the complexes allowed us to establish the coordination mode of the metal in complexes. Thermal properties, TG-DTA of these complexes were studied. TG- DTA and other analytical methods have been applied to the investigation of the thermal behavior and structure of the compounds [M(L)2]Cl2M= Hg, Pd. Thermal decomposition of these compounds is multi-stage processes.

A New Green Process for Synthesising High Quality PLLA Materials

2013 ◽  
Vol 750-752 ◽  
pp. 1377-1380 ◽  
Author(s):  
Hui Li Shao ◽  
Xian Jue Zhou ◽  
Xue Chao Hu
Keyword(s):  
Molecular Weight ◽  
Ring Opening ◽  
Average Molecular Weight ◽  
Gel Permeation Chromatography ◽  
Ring Opening Polymerization ◽  
Green Process ◽  
Weight Average Molecular Weight ◽  
H Nmr ◽  
Ft Ir ◽  
C Nmr

Synthesis of Poly(L-lactide) (PLLA) by the ring-opening polymerization (ROP) of L-lactides in supercritical carbon dioxide (SC-CO2) with co-solvent were studied. Effects of kinds of co-solvent on the molecular weight (MW) and the molecular weight distribution (MWD) of the resultant polymers were investigated by the gel permeation chromatography (GPC). The resultant polymers were also characterized with1H NMR,13C NMR and FT-IR. It was found that PLLA with high purity and almost without racemization could be obtained by this technology and the acetone is the best co-solvent for this kind of polymerization. By using stannous octoate as initiator and acetone as co-solvent, PLLA having a weight-average molecular weight (Mw) near to 9×104and polydispersity index (PDI) of 1.7 was successfully synthesized.

scholarly journals Preparation of Higher Molecular Weight Poly (L-lactic Acid) by Chain Extension

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Chenguang Liu ◽  
Yuliang Jia ◽  
Aihua He
Keyword(s):  
Molecular Weight ◽  
Lactic Acid ◽  
Average Molecular Weight ◽  
Hexamethylene Diisocyanate ◽  
Chain Extension ◽  
Poly Lactic Acid ◽  
Weight Changes ◽  
H Nmr ◽  
Left Handed ◽  
Ft Ir

High molecular weight poly (lactic acid) (PLA) was obtained by chain extending with hexamethylene diisocyanate (HDI). The influences of the amount of chain extender, reaction time, and molecular weight changes of prepolymers on the poly(lactic acid) were investigated. PLA prepolymer with a viscosity, average molecular weight (Mη) of 2 × 104 g/mol was synthesized froml-lactide using stannous octoate as the catalyst. After 20 min of chain extension at 175°C, the resulting polymer hadMwof 20.3 × 104 g/mol andMnof 10.5 × 104 g/mol. Both FT-IR and1H-NMR verified that the structure of PLA did not change either before chain extending or after. The optically active characterized that the chain extending-product was left handed. DSC and XRD results showed that both theTgand the crystallinity of PLA were lowered by chain-extension reaction. The crystalline transformation happened in PLA after chain extending, crystallineα′form toαform.

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