Polymer low permeability for balls

[yobacan]

I have 2 interesting questions, I believe, regarding polymer properties. I am designing a ball (pretty much like a basketball in size and appearance) to be used inside pressure vessels for certain corrosive fluids. The ball is inflated with air to a certain pressure in order to cushion extreme pressures in the pipeline (water-hammer). These balls will expand and contract according to pressure drops or pressure rises in water, respectively.

1) First question: These balls be in contact with certain corrosive fluids (under pressure) so I am looking for any or many polymers to be used as the external layer of the ball, so that it does not suffer from exposion to these special corrosive fluids. I have chemical properties of some of them, but I first ask this for any general corrosive fluid, not one in specific.

2) Second question: So far, I have been using polybutadiene as external polymer in the ball and butyl rubber as internal layer, but I believe there could be better choices in terms of lower permeability, as long as the other options can also be moulded and used as the external layer in a ball, for a reasonable cost (i.e, commercial polymers). The idea is to find also a polymer that can hold for a longer time the air inside the ball.

Regards

Felipe

 

[Navin A S]

1) For the first question, there are several polymers that may be suitable for use as the external layer of your ball. These include polyethylene, polypropylene, polyurethane, fluorinated ethylene-propylene (FEP), and polytetrafluoroethylene (PTFE). Each of these polymers have different chemical and mechanical properties which will affect their suitability for your application. Additionally, a range of coatings can be applied to these polymers to further improve their resistance to corrosive fluids. 2) For the second question, there are several possible options for a polymer with low permeability which could be used as the external layer of your ball. Examples of these include FEP, PTFE, and other fluoropolymers. Additionally, some proprietary blends of elastomers, such as EPDM or Viton, can offer good barrier properties against air and fluids. As with the previous question, each of these materials has different mechanical and chemical properties which will affect their suitability for your application. It is important to consider all of these factors when selecting the most appropriate material for your ball.