Sinochem launches a special epoxy resin for hydrogen storage tanks

In terms of structure, type III and type IV composite hydrogen storage bottles are mainly composed of an inner tank, a middle layer, an outer protective layer and a sealing structure. The middle layer usually uses carbon fibre/resin reinforced composite materials while the outer protective layer usually uses glass fibre/resin reinforced composite materials.

In order to further improve the performance of composite materials for high-pressure hydrogen storage cylinders, Sinochem International has developed two new epoxy resin formula products for filament winding – 9821A/B and 9824A/B, respectively suitable for type III hydrogen storage cylinders and type IV hydrogen storage cylinders.

According to Sinochem International, these two new products have excellent process formability, mechanical strength, toughness, heat resistance and other characteristics, which can extend the service life of high-pressure hydrogen storage cylinders while further improving their safety and stability. 

Viscosity and pot life

Sinochem International’s new epoxy resin products have low viscosity and good wettability. They can easily enter the gaps between carbon fibres, glass fibres and other fibres, reducing the difficulty of process molding. Lower viscosity also helps the resin to expel bubbles and avoid defects such as bubbles on the surface of the composite material and pores inside the composite material after the resin is solidified.

The pot life of the resin matrix refers to the application time of the two-component or multi-component epoxy resin after mixing. Currently, the thickness of composite materials for high-pressure hydrogen storage bottles is generally between 20-30 mm, and the molding process requires a long time, which requires the resin to have a longer pot life to ensure better product molding effects. Sinochem International’s new epoxy resin products have a long pot life, which ensures that the resin has sufficient operating time during the winding molding process and is fully infiltrated and mixed with carbon fibre and glass fibre. This ultimately has a good impact on the performance of composite materials.

Mechanical properties and toughness

During the use of high-pressure hydrogen storage bottles, with repeated filling and consumption of hydrogen, the pressure difference at the interface of the composite material can easily lead to material yielding, blistering and interface tearing.

Sinochem International claims that its new epoxy resin products have strong cohesion and a dense molecular structure. Through solidification reaction, it can form a layer of rigid and high-strength composite material with carbon fibre and glass fibre, further improving the strength of the main body of the pressurized hydrogen storage cylinder and helping gas cylinders maintain structural stability in high pressure environments.

Heat resistance and stability

Hydrogen is a flammable gas. During storage and transportation, the safety and stability of hydrogen storage bottles must be ensured to prevent hydrogen leakage or explosion caused by high temperatures.

Sinochem International’s new epoxy resin products have excellent heat resistance due to their unique chemical structure and solidified polymer network structure. Even if there are temperature changes during vehicle driving, the stability of the material structure and performance can be maintained to avoid the composite materials of high-pressure hydrogen storage cylinders to soften, expand or crack, ensuring the safe storage and transportation of hydrogen.

Cover photo:  Sinochem International.