Mechanical properties of nylon 6 subjected to photodegradation

Mai, Yiu‐Wing; Head, D. R.; Cotterell, B.; Roberts, Bryan W.

doi:10.1007/bf00550376

Cited by 10 publications

(5 citation statements)

References 11 publications

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“…Instead, other methods such as molecular weight analysis, DSC, X-ray diffraction (XRD), electron spin resonance (ESR) or UV-Vis spectroscopy should be used. 25,39 Some studies 37,40,41 on polyamide degradation have attributed a reduction in elongation at break along with constant or increasing strength to the crosslinking of the polymer structure. Other studies 38,[41][42][43][44] showed a decrease in maximum tensile strength, along with a decrease in elongation at break, which was explained by the chain scission reactions as the main process leading to degradation.…”

Section: Discussionmentioning

confidence: 99%

“…25,39 Some studies 37,40,41 on polyamide degradation have attributed a reduction in elongation at break along with constant or increasing strength to the crosslinking of the polymer structure. Other studies 38,[41][42][43][44] showed a decrease in maximum tensile strength, along with a decrease in elongation at break, which was explained by the chain scission reactions as the main process leading to degradation. In the present study, a decrease in breaking force along with a small reduction in elongation at break were observed, which suggest that chain scission is the main degradation process.…”

Section: Discussionmentioning

confidence: 99%

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Ageing of climbing ropes with and without hydrophobic coating

Sedláček

Roso

Viel³

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part P:

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The effects of 4 months of weather exposure on the ageing of dynamic climbing ropes made of polyamide 6 were studied and differences between ropes with and without hydrophobic coating were examined. The polyamide degradation of the rope yarns was studied using infrared spectroscopy and a quasi-static tensile test. The number of falls to failure and the maximum force on the climber in a fall were evaluated with a drop test according to the UIAA 101 standard. Moreover, changes in the length of the ropes due to weathering were measured. The following results were found. After 4 months of weathering, sheath yarns of the coated rope showed a greater decrease in breaking force than those of the uncoated rope, which might be due to reactions of polyamide with radicals formed during the photo-induced oxidation of the coating. In contrast, the core yarns from the uncoated rope showed a greater decrease in breaking force than those from the coated rope, probably due to prolonged exposure of the uncoated core to water with possibly dissolved atmospheric acids. Furthermore, the decrease in the number of falls to failure was greater in the uncoated than in the coated rope. This difference was explained by a mechanism of changes in radial pressure of the sheath on the core. Regarding the maximum force on the climber, no significant changes due to ageing were observed during the drop test. Thus, it was concluded that 4 months of weather exposure do not pose a safety risk for climbing ropes, but the negative effect of coating on the ageing of polyamide might be detrimental when it comes to static personal safety equipment, such as slings or accessory cords.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Ageing of climbing ropes with and without hydrophobic coating

Sedláček

Roso

Viel³

et al. 2021

Proceedings of the Institution of Mechanical Engineers, Part P:

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“…The degradation of Nylon 6 is a well‐researched [ 30–53 ] irreversible process. In this environment, the UV radiation acting as an initiator starts a radical oxidation process in the Nylon that could lead to (depending on the wavelength) chain breaking [ 35–37 ] or crosslinking (under 300 nm [ 38,39 ] ).…”

Section: Introductionmentioning

confidence: 99%

The effect of the titanium dioxide nanoparticles on the morphology and degradation of polyamide 6 prepared by anionic ring‐opening polymerization

Semperger

Osváth

Pásztor

et al. 2022

Polymer Engineering & Sci

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Thermoplastic Resin Transfer Molding can be used to produce polyamide 6-based composites from ε-caprolactam by anionic ring-opening polymerization. However, the service life and applicability of these composites are limited because polyamide 6 is sensitive to UV radiation. Therefore, we analyzed the effect of nanosized titanium dioxide on the UV stability of polyamide 6 produced from ε-caprolactam. Despite the very low viscosity of caprolactam, we dispersed nanoparticles homogeneously in it before producing polyamide 6 from it. We have shown that both structural and chemical changes occur in the material under UV exposure. We proved that UV irradiation increases the crystalline fraction of the samples. This is caused by the shortening of the polymer chains. The crystalline fraction increases less with the addition of TiO 2 , which shows its UV protective effect. The particles prevent the rays from reaching the inside of the sample, producing a chalking effect on the surface.We analyzed and proved the chemical change in the samples by FTIR and color measurement. Our results showed that surface-treated titanium dioxide was more stable, and the ideal filler content was about 0.6 w/w%, above which photodegradation accelerated. This can be attributed to the photocatalytic activity of the titanium dioxide particles.

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“…UV irradiation is believed to clean the polymer surface by removing the organic contamination and to change the molecular structure of the shallowsurface region [12][13][14][15] . Therefore, during the UV exposure, the polyamide undergoes degradation of the polymer chain 13,16,17) .…”

Section: Introductionmentioning

confidence: 99%

“…Therefore, during the UV exposure, the polyamide undergoes degradation of the polymer chain 13,16,17) . As a result, the UV-irradiated polyamide surface region can easily be dissolved or swelled by an organic solvent.…”

Section: Introductionmentioning

confidence: 99%

Effect of ultraviolet light irradiation and sandblasting treatment on bond strengths between polyamide and chemical-cured resin

et al. 2014

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The aim of this study was to evaluate the effects of ultraviolet light (UV) irradiation and sandblasting treatment on the shear bond strength between polyamide and chemical-cured resin. Three types of commercial polyamides were treated using UV irradiation, sandblasting treatment, and a combining sandblasting and UV irradiation. The shear bond strength was measured and analyzed using the Kruskal-Wallis test (α=0.05). Comparing shear bond strengths without surface treatment, from 4.1 to 5.7 MPa, the UV irradiation significantly increased the shear bond strengths except for Valplast, whose shear bond strengths ranged from 5.2 to 9.3 MPa. The sandblasting treatment also significantly increased the shear bond strengths (8.0 to 11.4 MPa). The combining sandblasting and UV irradiation significantly increased the shear bond strengths (15.2 to 18.3 MPa) comparing without surface treatment. This combined treatment was considered the most effective at improving the shear bond strength between polyamide and chemical-cured resin.

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Mechanical properties of nylon 6 subjected to photodegradation

Cited by 10 publications

References 11 publications

Ageing of climbing ropes with and without hydrophobic coating

Ageing of climbing ropes with and without hydrophobic coating

The effect of the titanium dioxide nanoparticles on the morphology and degradation of polyamide 6 prepared by anionic ring‐opening polymerization

Effect of ultraviolet light irradiation and sandblasting treatment on bond strengths between polyamide and chemical-cured resin

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