Development of thermoplastic based self-healing smart elastomers and investigation of their performance properties

In this thesis study, the production of functionalized styrene block copolymer-based thermoplastic elastomer (TPE) blends using three different cyclic amine compounds and an aliphatic diamine compound by reactive blending method in melt state and their self-healing properties with the effect of external thermal stimulation were examined. Poly(styrene-b-ethylene/butylene-b-styrene) (SEBS) and maleic anhydride grafted SEBS (SEBS-g-MAh) as TPE phase, paraffinic oil as plasticizer, 3-amino,1,2,4-triazole (TA), aminopyrazine(APz) and 2-aminopyrimidine (APm) as cyclic amine compounds, and 1,12 diaminododecane (DA) as aliphatic diamine compound, and zinc nitrate as metal salt to form metal-ligand interactions were used. Reactive compounds were prepared by a three-stage blending process in a twin-screw melt mixing device without using any catalyst, and the structural, morphological, rheological, viscoelastic, mechanical and self-healing properties of functional TPEs were examined. The healing efficiencies of reactive compounds were determined depending on the composition and healing conditions. Experimental studies and results indicated that imide bonds were formed as a result of the reactions between cyclic amine compounds and maleic anhydride groups onto copolymer chain and amide bonds were formed as a result of the reactions between aliphatic diamine and maleic anhydride and proceed crosslinking reactions based on the FTIR, dissolution tests, DMA and rheometer tests. Moreover, it was found that the functional TPEs prepared using aliphatic diamine did not show self-healing behaviour efficiently due to the formation of chain restriction effect of crosslinking but the functional TPEs prepared with cyclic amine compounds exhibited enhanced mechanical properties and self-healing behaviour induced with temperature triggering in the range of 80-120 ºC due to the formation of dynamic interactions such as hydrogen interactions and metal-ligand bonds.