Hydrolytic ageing of polyamide 11—effect of carbon dioxide on polyamide 11 hydrolysis

Merdas, I.; Thominette, F.; Verdú, J.

doi:10.1016/s0141-3910(02)00358-0

Cited by 44 publications

(27 citation statements)

References 5 publications

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“…Therefore, the pH mainly affects the equilibrium process of the system. These results are in agreement with those reported by Merdas et al, 5 where two main acid effects on hydrolysis are reported: catalysis, of which the main consequence is an increase of hydrolysis rate, and amine scavenging with essentially, a shift of the equilibrium toward higher conversions, i.e., lower viscosities. To presume the effect of catalysis by H þ ions, the degradation kinetic (r) is given by eq.…”

Section: Resultssupporting

confidence: 93%

“…Hence, at high conversions, i.e., close to equilibrium, another process, e.g., amine scavenging, can play an important role. 5 The DSC curves of samples of virgin and aged PA-11 at 120 C in oilfield water are shown in Figure 5. The first heating cycle, Figure 5(a), shows a slight increase in the melting point (T m ) of the PA-11 with ageing time.…”

Section: Resultsmentioning

confidence: 99%

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Ageing of polyamide 11 used in the manufacture of flexible piping

Romão

Castro

Filho

et al. 2009

J of Applied Polymer Sci

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The influence of temperature and pH on the ageing of piping made from polyamide 11 (PA-11) was studied using water from an oilfield (pH ¼ 5.5) and deionized water (pH ¼ 7.0) with monitoring by corrected inherent viscosity (CIV) measurements. The hydrolytic degradation was more extensive at high temperatures in oilfield water. When the system reaches equilibrium, the pH affects mainly the CIV plateau values. Thermogravimetry, energydispersive X-ray spectroscopy, differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy measurements were also used to investigate aspects involved in the ageing PA-11. The hydrolytic degradation of PA-11 leads to formation of low molar mass compounds, such as oligomers dispersed in the polymeric matrix. This is a process that occurs preferentially in the amorphous domain of PA-11, which leads to an increase in the degree of crystallinity and the formation of a new c-phase.

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Section: Resultssupporting

confidence: 93%

Section: Resultsmentioning

confidence: 99%

Ageing of polyamide 11 used in the manufacture of flexible piping

Romão

Castro

Filho

et al. 2009

J of Applied Polymer Sci

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“…The tests were performed at two different temperatures, 110 and 120 C, during a total immersion time of 50 days. [5] After, thermal properties [thermogravimetry and differential thermal analysis (TG/DTA), DSC, and DMA] and multielemental analyses (ED-XRF) were used in PA-11 characterization according to the ageing time: 0, 3,5,7,13,16,19,21,25,30,35,42, and 50 days (for 110 C); and 0, 3,5,7,9,13,16,19,22,25,30,35,42, and 50 days (for 120 C).…”

Section: Ageing Testmentioning

confidence: 99%

“…[3,4] Generally, the PA-11 is plasticized with N-butyl-benzenesulfonamide in 12 wt.% concentration to improve flexibility and to reduce hardness. [3,5,6] However, the PA-11 and other polyamides in the presence of water undergo hydrolytic degradation process, [3,5,[7][8][9] being accelerated under high temperatures (>90 C) and/or in acid medium (carbon dioxide, hydrogen sulfide, and organic and inorganic acids), pH < 7. This degradation mechanism causes mainly a decrease in weight average molar mass, M w , and the loss of plasticizer and mechanical properties of PA-11.…”

Section: Introductionmentioning

confidence: 99%

Monitoring the polyamide 11 degradation by thermal properties and X‐ray fluorescence spectrometry allied to chemometric methods

et al. 2012

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The influence of temperature (110 and 120 °C) on the ageing of piping made from polyamide 11 (PA‐11) containing 10–12% of plasticizer was studied using deionized water (pH ≈ 7.0). A clean analytical methodology has been employed for quality control of polymeric materials: energy‐dispersive X‐ray fluorescence spectrometry (ED‐XRF). It provides a fast and suitable technique to characterize chemical elements because of its multielemental capability, good sensitivity, high precision, short analytical time, and nondestructive nature. Herein, the content of additive in PA‐11 was monitored from ED‐XRF measurements where the abundance of the S line is directly related to the ageing time, agreeing with the thermogravimetric analysis. The XRF data were allied to chemometric treatment to classify PA‐11 samples according to the amount of additive and weight average molar mass change, predicting the ageing time, and viscosity values of PA‐11. Therefore, the XRF can be used as a clean analytical methodology to monitor the PA‐11 degradation, thus eliminating the use of toxic organic solvents (necessary to viscosity measurements) and reducing the working time. Also, the effect of hydrolysis on the structure over time and the material morphology were monitored through measurements of dynamic mechanical analysis and differential scanning calorimetry. Copyright © 2012 John Wiley & Sons, Ltd.

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“…belong to this category. then, the reverse reaction cannot be neglected and the kinetic model is somewhat more complicated (Jacques et al, 2002;El Mazry et al, 2012), especially when acids are present (Merdas et al, 2003). it can be easily shown that the equilibrium molar mass M We (when t AE •) is given by:…”

Section: Mechanisms Of Chemical Ageing: Hydrolytic Processesmentioning

confidence: 99%

Understanding the durability of advanced fibre-reinforced polymer (FRP) composites for structural applications

Benzarti¹,

Colin²

2013

Advanced Fibre-Reinforced Polymer (FRP) Composites for Structural Applications

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Fibre-reinforced polymer (FrP) composites are increasingly being used in the field of civil engineering, either for the rehabilitation/retrofitting of existing infrastructures or for the construction of new structural elements. However, such applications are still recent and there are still unresolved questions regarding the long-term durability of FrP reinforcements or structural elements under service conditions, and their behaviour under accidental fire events as well. In this chapter, it is proposed to highlight the basic mechanisms involved in the environmental degradation of FrP composites, with a large emphasis on ageing mechanisms of the polymer matrix and their consequences on the mechanical properties. the last section is specifically devoted to the fire behaviour of polymer composites and also recalls existing fire-proofing solutions.

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Hydrolytic ageing of polyamide 11—effect of carbon dioxide on polyamide 11 hydrolysis

Cited by 44 publications

References 5 publications

Ageing of polyamide 11 used in the manufacture of flexible piping

Ageing of polyamide 11 used in the manufacture of flexible piping

Monitoring the polyamide 11 degradation by thermal properties and X‐ray fluorescence spectrometry allied to chemometric methods

Understanding the durability of advanced fibre-reinforced polymer (FRP) composites for structural applications

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