Long-term durability of thermoplastic elastomer containing antiviral additives for mobility applications

Abstract

In the mobility market, there is a demand from customers for antimicrobial protection. As a result, the market has grown considerably to provide antiviral and antimicrobial polymers and coatings. This study examines how the efficacy of a non-commercial antimicrobial thermoplastic elastomer will change over the life of the application. Using an example application of an electric scooter handlebar grip, durability requirements were identified, and antiviral efficacy (exceeding a log value of 3 or >99.9 microbial growth reduction) was compared before and after testing. A scooter handlebar grip was selected as the ideal example application as it was a high-touch surface, with several different riders. During the start of this study, scooter companies were encouraging their riders to disinfect scooter handlebars before riding, use hand sanitizer, and wear gloves. If the handlebar grip could be antimicrobial, then they could eliminate these steps and provide a safe ride for the users. In order to simulate long-term durability, UV exposure, temperature, humidity, artificial sweat, sunscreen, insect repellent, and abrasion tests were performed and evaluated in terms of antiviral activity. Accelerated weathering reduced the virucidal activity of the sample versus unexposed antiviral thermoplastic elastomer (TPE). However, the efficacy increased with contact time from 90% to 96.83% at 30 and 120 min, respectively. Abrasion resistance of antiviral TPE showed a volume loss of 66 mm³ compared to control samples of 83 mm³. The antiviral TPE sample exhibited slightly lower efficacy compared to the control after exposure to the artificial sweat (99.43% vs. 99.95%). Additionally, a skin tolerance test conducted on rabbits showed that antiviral TPE was not an irritant and showed no dermal toxicity. The outcome of this study will lead to the development of long-term durable antimicrobial material for the transportation industry.