PhD thesis defence Indriasari

On Wednesday, October 20th 2021, Ms. Indriasari has successfully defended her PhD thesis entitled: “Tailoring rubber compound and processing for balancing the properties of aircraft tire retreads”.

Short Summary

Aircraft (AC) tires are one of the primary components in an aircraft that have to undergo frequent replacement due to the harsh operating conditions. To extend the service life of the AC tire tread, it is of utmost importance to optimize the performance. The key requirements are low hysteresis, excellent mechanical properties, high wear resistance, good adhesion to the reinforcing fabric, and good processability. The goals of the thesis are to develop AC tire retreads with good processability and high tackiness for good retreadability, additionally to tailor the above-mentioned properties. This thesis covers the process optimization of NR/BR-based rubbers filled with carbon black, silica, and their blends. DOE was used to determine the significant parameters which influence the properties of AC tire retreads. Among four types of BR investigated, High-Cis Long Chain Branched BR (HC LCB BR) significantly improve the processability and the dispersion of fillers. The use of HC LCB BR and silica lower the hysteresis which is crucial for AC tire treads. The aging properties also improve considerably when silica is added while maintaining high stress-strain properties. Tackiness can be enhanced by the incorporation of resins which is beneficial in the retreading process. Furthermore, Terpene phenol and hydrocarbon C9 resin in silica-filled NR/BR vulcanizates show a promising improvement in overall tire performance: ice traction, wet skid resistance as well as heat build-up, justifying more in-depth investigations into this possibility in real AC tire retreads.