water, hydrogen, carbon dioxide, natural gas, permeability, permeation, liquid to gas diffusion, solubility and time lag regarding polymer, plastics, water and composite materials

more on diffusion

Diffusion of liquids, vapours and gases in polymer and composite materials is usually an important design parameter. Service life of civil structures and chemical processing equipment , shelf life of electronic packages, functioning of membrane and controlled release applications, and so on: they all - more or less - depend on diffusion time and diffusion nature. Hence, one can imagine that rigorous determination of diffusion phenomena in your application, can make a difference of one, ten or perhaps a hundred years of safe operation. Our analysis capabilities include complex diffusion and permeability determinations regarding multilayer materials - laminates and composites - and multicomponent (like inks, alkaline acqueous solutions, solutions containing herbicides, chemical processing mixtures) diffusion.
case stories
Glass Reinforced Polyamide Liner on a High Strength Steel Pipeline
A major concern for future, high capacity hydrogen pipelines is long term durability at internal gas pressure at 100 bar. It is well known that, already at one third of this pressure, carbon steels are susceptible to hydrogen embrittlement and cracking. In this case we describe integrated diffusion and mechanical considerations in case we would like to increase the lifetime of such a pipeline. Here, we will specifically focus on relining of an existing natural gas pipeline by glass reinforced polyamide, for future – high pressure - transport of hydrogen.
100% Nitrogen in Tyre Composites
Usually we fill our tyres with Air. Nowadays there are several discussions in magazines and internet on whether it would be better to fill tyres with 100% Nitrogen or Carbon Dioxide instead of Air. The diffusion resistance layer of tyres are made from a polymer rubber called Polyisobutylene, and a few percent of Isoprene. In this case history it is shown that this polymer has a better diffusion resistance against Nitrogen than Oxygen. Moreover the practical implications of this difference are described.
Methanol Diffusion in GFRP
Here we demonstrate how mass transfer of liquids and saturated vapours is applied in an industrial application. We were commissioned to assess whether it is possible to use a GFRP (Unsaturated Polyester Glass Fibre Reinforced Plastic) pipeline for the transport of methanol. Apart from past effects of alkaline water transport on sustainability of this pipeline, it is shown how the methanol flux changes in the time period evaluated. In this example the counter diffusion of polluting chemicals in ground water was not taken into account.
Carbon Dioxide Diffusion through PET
In this case history we see the effect of diffusion of carbon dioxide through PET bottle walls. Especially at lower gas pressures, the swelling of the polymer due to gas diffusion is less important than in case of liquid and vapour diffusion. But here, the shelf life of the bottled product is affected. For assistance with food and pharma packaging do not hesitate to contact us.
Biodiesel Diffusion through Containment Materials
Biodiesel is one of the promising developments with regard to sustainable energy. In this case the influence of ethanol content in biodiesel on the permeation and chemical resistance of a car's fuel system, based on performance polymers like PEEK, PPS and PA/PI, is assessed. This extensive case shows how we deal with topics like: effect of different component of a chemical mixture on the break through / lag time, diffusivity coefficient, (maximum) solubility, swelling behaviour, permeability and mechanical performance.
related forum threads
- laboratory techniques to determine diffusivity, solubility, permeability
- the meaning of diffusion coefficient? - comprehensive explanation
- diffusion of small molecules into plastics filled with inorganic fillers
- software for chemicals diffusion in multilayer laminate for packaging?
- gas stream diffusion - hydrogen sulfide - in polyvinylidene fluoride
- diffusion rate of monoethylene glycol (meg) in hydraulic oil (brayco)
- dichloromethane diffusion in high density polyethylene (hdpe)
- inflate your isobutylene tyres with air, carbon dioxide or pure nitrogen?
- diffusion, permeability of hydrogen in epoxy, polyester, polyurethane..
- water diffusion, solubility in advanced multilayer laminate: pe, metal, pet
- different perspectives regarding diffusion of hydrogen in of polyethylene
- effect of temperature on the diffusion coefficient (arrhenius law)
- radon diffusivity in polyvinylchloride (pvc)
- anomalous diffusion of water / carbon dioxide in pdms (silicone rubber)
- gasoline diffusion in polymer and reinfored plastic materials
more on our permeation capabilities
We are specialized in diffusion, solubility and permeation characteristics of coatings, linings and structural polymers & composites. Our analysis facilities include gravimetric, chromatographic and electrical impedance spectroscopy, all in compliance with ASTM test methodology. This enables us to obtain permeability, solubility, diffusion, swelling and time lag properties of gases, vapours, solvents and mixtures with regard to your cast polymer materials, but also combinations of plastics with metals, fibres, fillers, nanoparticles, etc. Furthermore, our referenced simulation programmes in combination with above described experimental results, allow us to assess the permeability behaviour of your polymer material in industrial conditions or other real life applications. Visit support for more information or click here to send us your inquiry, without any obligation. For discussion on permeability (such as water, hydrogen, carbon dioxide and lpg), but also chemical resistance and mechanical properties of plastic and composite materials, visit the materials forum. To give an indication of diffusion rates of gases, vapours and liquids, solubility and permeability we tabled a selection of our figures under "library" in the upper menu bar. Below you will find some of the related case stories. If you want to learn more on the physical fundamentals of diffusion, please click this forum message.