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Pasquale, Giovanna Di; Rosa, Angela Daniela La; Recca, A.; Carlo, S. Di; Bassani, Marco; Facchetti, S.

doi:10.1023/a:1018613709545

Cited by 3 publications

(3 citation statements)

References 5 publications

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“…Polyamide (PA) was usually studied on its degradation mechanism and kinetics of pyrolysis through the method of GC‐MS, DTA, TGA, FTIR, NMR, SEM, and so on 7–16. In recent years, oxygen uptake and chemiluminescence (CL) were also applied to the study on the oxidation mechanism of PA and the function of stabilizers, which was useful though the relationship between the CL intensity and the rate of oxygen uptake had not been very clear 17–24.…”

Section: Introductionmentioning

confidence: 99%

Study on the long‐term thermal‐oxidative aging behavior of polyamide 6

Ying

Yang

2008

J of Applied Polymer Sci

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The long-term thermal-oxidative aging behavior of polyamide 6 (PA6) was studied by comparison with the stabilized sample in this work. The variation of mechanical properties of the pure and the stabilized samples of PA6 with aging time at 1108C, 1308C, and 1508C were investigated, respectively. The aging mechanism of PA6 under heat and oxygen was studied in terms of the reduced viscosity, crystallization behavior, dynamic mechanical behavior, and chemical composition through the methods of polarized light microscopy (PLM), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), X-ray photoelectron energy spectrum (XPS), and so on. The results indicated that at the initial stage of aging, the molecular crosslinking reaction of PA6 dominated resulting in the increase of the mechanical strength, reduced viscosity, and the glass transition temperature of the sample. And the molecular degradation dominated in the subsequent aging process resulting in the decrease of the melting temperature, the increase of the crystallinity, and the formation of the oxides and peroxides products.

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Section: Introductionmentioning

confidence: 99%

Study on the long‐term thermal‐oxidative aging behavior of polyamide 6

Ying

Yang

2008

J of Applied Polymer Sci

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“…Other researchers consider that at high level of humidity, the reverse polyamidation would induce high concentrations of carboxylic groups, making decarboxylation the predominant degradation mechanism . However, this second pathway cannot explain the non‐stoichiometric CO 2 production (without apparent increase of the CP production rate, as observed by Schaffer et al).Furthermore, CP/CP derivatives may react with NH 3 /aliphatic amines or HMD through the following mechanisms: i) enolization [Reaction 10 and Reaction 16 (Table ), forming alkylated CP as 2‐ethylCP]; ii) nucleophilic addition‐elimination (Reaction 9, 14, and 15, forming imines as Schiff bases and enamines), while additional studies have proven that cyclopentanone is also quite reactive to (iii) self‐condensation (forming 2‐cyclopentylCP, 2‐cyclopentylideneCP, aromatic rings bonded to polyciclic structures); (iv) combined mechanisms leading to free pyridine (PY) and derivatives.Most experimental publications have reported that cyclopentanone is found mainly in the free form (CP). From this point of view, the mechanism proposed by Steppan et al sounds a bit inconsistent, since it considers strictly the generation of cyclopentanone as a terminal functionality ( e cp ).…”

Section: Assumptions and Modelingmentioning

confidence: 99%

“…Most experimental publications have reported that cyclopentanone is found mainly in the free form (CP). From this point of view, the mechanism proposed by Steppan et al sounds a bit inconsistent, since it considers strictly the generation of cyclopentanone as a terminal functionality ( e cp ).…”

Section: Assumptions and Modelingmentioning

confidence: 99%

Modeling of Polyamide 66 Solid State Polymerization: Drawing a Chemical Reaction Scheme

Filgueiras

Vouyiouka

Konstantakopoulou

et al. 2014

Macro Reaction Engineering

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A chemical reaction scheme is proposed here to describe the polyamide 66 (PA 66) solid state polymerization (SSP) with effective kinetic parameters. The main objective of the suggested model is to predict the maximum molecular weight attainable at each SSP isotherm, which is in turn determined by the occurrence of polymer chain degradation coupled to other important side reactions. Accordingly, a number of side reactions have been firstly considered, based on which a comprehensive particle model was constructed to predict PA 66 kinetics, equilibrium, and transport phenomena. The SSP model parameters were estimated with a maximum-likelihood estimator, using data measured under kineticand diffusion-controlled process conditions for reaction temperatures in the range of 160-200 8C and reaction times up to 8 h. Calibration models were also developed to allow the determination of PA 66 solution viscosities.

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Soto‐Valdez

Gramshaw

2000

Journal of Materials Science Letters

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Cited by 3 publications

References 5 publications

Study on the long‐term thermal‐oxidative aging behavior of polyamide 6

Study on the long‐term thermal‐oxidative aging behavior of polyamide 6

Modeling of Polyamide 66 Solid State Polymerization: Drawing a Chemical Reaction Scheme

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