Accelerated ageing behaviour of poly ether block amide (PEBAX) and polybutylene terephthalate polyester (arnitel) thermoplastic elastomers

The thermoplastic elastomers-PEBAX (PA1074) and two grades of Arnitel (VT3108, VT7812) which are commonly used in a range of medical devices, were aged at temperatures of 40 -100℃ for a period of up-to 324 days, and at 60℃ with elevated humidity.Understanding the effects of ageing on the behaviour of these thermoplastic elastomers used commonly in safety medical applications is crucial.The samples were characterised during ageing via mechanical testing, TGA (Thermogravimetric analysis) and DSC (Differential scanning calorimetry).It was observed that the samples discoloured during ageing with greater changes being observed at the higher ageing temperatures.The materials also displayed an increase in brittleness as a result of ageing, with the PEBAX showing more pronounced changes compared to the two grades of Arnitel tested.