Non-isothermal kinetics of thermal degradation of chitin

Georgieva, Velyana G.; Zvezdova, Dilyana; Vlaev, L. T.

doi:10.1007/s10973-012-2359-6

Cited by 82 publications

(46 citation statements)

References 37 publications

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“…If the correct g() is used, a plot of ln[g()/T 2 ] against 1/T should give a straight line from which the values of the activation energy E and the pre-exponential factor A in Arrhenius equation can be calculated. The formal expressions of the functions g() depend on the conversion mechanism and its mathematical model [10][11][12]15,17]. The latter usually represents the limiting stage of the reaction-the chemical reactions; random nucleation and nuclei growth; phase boundary reaction or diffusion.…”

Section: Theoretical Approach and Calculation Proceduresmentioning

confidence: 99%

“…From the theory of the activated complex (transition state) of Eyring [10][11][12]15,20,21], it is known that:…”

Section: Theoretical Approach and Calculation Proceduresmentioning

confidence: 99%

“…Overall kinetics can be easily obtained by measuring the change in mass of a sample with time based on isothermal or non-isothermal thermogravimetric data [10][11][12]. Some valuable parameters, such as apparent activation energy E, pre-exponential factor A, and reaction order n can be calculated from a thermogravimetric curve.…”

Section: Introductionmentioning

confidence: 99%

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Non-Isothermal Degradation Kinetics of Hybrid Copolymers Containing Thermosensitive and Polypeptide Blocks

Ivanova¹,

Dimitrov²,

Georgieva³

et al. 2012

OJPChem

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Novel, self-associating hybrid copolymers were synthesized via controlled ring-opening polymerization of -carboxyanhydride of Z-L-lysine (Z-L-Lys-NCA), initiated by amino-functional macroinitiators. A poly(N-isopropylacrylamide) (PNIPAm)-based macroinitiator containing 10 mol% of polyoxyethylene grafts and a terminal primary amine group in the form of ammonium hydrochloride (PNIPAm-g-PEО) was synthesized and used to initiate the ammoniummediated ring-opening polymerization of NCA described by Dimitrov and Schlaad [1]. Thus, hybrid copolymers ((PNIPAm-g-PEO)-b-PLys) with controlled molar-mass characteristics and functionality were obtained. The potential applications of PNIPAm-based copolymers in the systems for controlled drug release, immobilization of enzymes and protein purification have aroused great interest in the studies of their properties and behaviour. The thermal stability and thermodynamic properties of the copolymers obtained were studied. The differential thermal analysis of polyfunctional hybrid copolymers (PNIPAm-g-PEO)-b-PLys) showed that thermooxidative destruction occurs in two stages: primary, of the unstable fragments (grafted chains of PEO); and secondary, of the main polymer chains of poly(N-isopropylacrylamide) and poly(L-lysine). The kinetics of thermal degradation was evaluated and the values of the activation energy of the degradation process, changes of Gibbs free energy, enthalpy and entropy for the formation of the activated complex were also calculated.

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Section: Theoretical Approach and Calculation Proceduresmentioning

confidence: 99%

“…From the theory of the activated complex (transition state) of Eyring [10][11][12]15,20,21], it is known that:…”

Section: Theoretical Approach and Calculation Proceduresmentioning

confidence: 99%

See 1 more Smart Citation

Non-Isothermal Degradation Kinetics of Hybrid Copolymers Containing Thermosensitive and Polypeptide Blocks

Ivanova¹,

Dimitrov²,

Georgieva³

et al. 2012

OJPChem

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“…Synthesized compounds were evaluated for their antimicrobial activity and all the compounds showed significant activity [11]. Non-isothermal kinetics of chitosan [12], chitin [13], cephalosporins [14], procaine and benzocaine [15] and theobromine [16] were studied in details and appropriate the decomposition kinetics models were proposed.…”

Section: Introductionmentioning

confidence: 99%

Kinetics of Thermal Decomposition of a Spirooxindole Compound under Non-Isothermal Condition

2016

Can Chem Trans

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A spirooxindole compound, namely 2′-amino-6′-(1H-indol-3-yl)-2-oxospiro[indole-3,4′-pyran]-3′, 5′-dicarbonitrile (AIOIPD) has been synthesized and characterized by microanalysis, FT-IR, mass spectrum and NMR ( 1 H and 13 C) techniques. The thermal decomposition of the compound was studied by thermogravimetric analysis under dynamic nitrogen atmosphere at different heating rates of 10, 15, 20 and 30 K min -1 . The kinetic parameters were calculated using model fitting (Coats-Redfern, CR) and model-free methods (Friedman, Kissinger-Akahira-Sunose, KAS and Flynn-Wall-Ozawa, FWO). The decomposition process of AIOIPD followed a single step mechanism as evidenced from the data. Existence of compensation effect is noticed for the decomposition of AIOIPD. Invariant kinetic parameters are consistent with the average values obtained by Friedman and KAS inconversional methods.

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“…The unique structural features of spirooxindoles together with diverse biological activities have made them privileged structures in new drug discovery [10]. Non-isothermal decomposition kinetics of chitosan [11], chitin [12], cephalosporins [13], procaine and benzocaine [14], theobromine [15] and spirooxindole [16] were studied in detail and appropriate kinetic models were proposed. 3-Chloro oxindoles are versatile starting materials for asymmetric organo catalytic synthesis of spirooxindoles.…”

Section: Introductionmentioning

confidence: 99%

Synthesis, characterization and thermal decomposition of 2’-amino-6’-(1H-indol-3-yl)-1-methyl-2-oxospiro-[indoline-3,4’-pyran]-3’,5’-dicarbonitrile under non-isothermal condition in nitrogen atmosphere

Nalini¹,

Jayachandramani²,

Suresh

et al. 2016

Eur. J. Chem.

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Non-isothermal kinetics of thermal degradation of chitin

Cited by 82 publications

References 37 publications

Non-Isothermal Degradation Kinetics of Hybrid Copolymers Containing Thermosensitive and Polypeptide Blocks

Non-Isothermal Degradation Kinetics of Hybrid Copolymers Containing Thermosensitive and Polypeptide Blocks

Kinetics of Thermal Decomposition of a Spirooxindole Compound under Non-Isothermal Condition

Synthesis, characterization and thermal decomposition of 2’-amino-6’-(1H-indol-3-yl)-1-methyl-2-oxospiro-[indoline-3,4’-pyran]-3’,5’-dicarbonitrile under non-isothermal condition in nitrogen atmosphere

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