Compared with poly(butylene terephthalate)/glycidyl methacrylate grafted poly(ethylene-octene) (PBT/POE-g-GMA) binary blends, supertough PBT-based ternary blends with little rigidity loss were successfully obtained by adding rigid polypropylene (PP) into PBT/POE-g-GMA blends to construct core-shell particles during melt blending. The effects of PP content and type on the phase morphology and mechanical properties of the blends were systematically investigated. Theoretical predictions and scanning electron microscopy observation showed that a core-shell structure was formed in PBT matrix with PP as the core and POE-g-GMA as the shell. The mechanical property tests showed that POE-g-GMA and PP had significant synergistic toughening effect. When PP with high melt flow index (H-PP) was used, PBT/POE-g-GMA/H-PP (70/15/15) blends possessed the highest Izod notched impact strength, which was 1.9-fold compared with PBT/POE-g-GMA (70/30) binary blends, while the tensile performance loss was little. The essential work of fracture tests was performed to evaluate the fracture resistance of different samples. The results demonstrated that PBT/POE-g-GMA/ PP ternary blends possessed much better resistance to crack propagation than PBT/POE-g-GMA binary blends. The decrease of interparticle distance and the fibrillation of core-shell particles activated intense matrix shear yielding, which was the reason for the high crack resistance of ternary blends.

A comparative study of morphology and properties of poly(butylene terephthalate)/carbon nanotubes (PBT/CNTs) nanocomposites with non-reactive and reactive elastomers was comprehensively performed. The carboxyl-functionalized CNTs showed uniform dispersion and formed an interconnecting network structure at relatively high content in both nanocomposites. However, the location of CNTs and the resulting morphology were different in these two nanocomposites as a result of chemical interactions between the reactive elastomer and functionalized CNTs. Evaluation of mechanical performance demonstrated that CNTs enhanced the tensile strength and modulus of both nanocomposites. However, the incorporation of CNTs did not enhance the toughness of the two nanocomposites, although elastomer particle size decreased in the nanocomposites with the non-reactive elastomer. The volume resistivity of both nanocomposites was extremely reduced with CNTs, but the volume resistivity of the nanocomposites with the non-reactive elastomer decreased more due to the more significant volume exclusion effect of the non-reactive elastomer. With the addition of a reactive elastomer and CNTs, electrical conductive PBT nanocomposites with balanced toughness−rigidity were obtained.

To promote the anti-aging performance of thermoplastic vulcanizates (TPVs) versus ultraviolet (UV)/O3 exposure, a nano-TiO2-loaded antioxidant (TiO2-KH570-MB) was prepared by a thiol–ene reaction between 2-mercaptobenzimidazole (MB) and modified nano-TiO2 (TiO2-KH570). Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis demonstrated the chemical linkage between MB and modified nano-TiO2, and the loading amount of MB was approximately 5.19 wt %. The contact angle test showed that the surface hydrophobicity of TiO2-KH570-MB was significantly increased due to the immobilization of MB. Scanning electron microscopy revealed that TiO2-KH570-MB was uniformly distributed in the TPV matrix. The anti-aging property of TPV compounds was tested in the device with high-intensity ultraviolet radiation and high-concentration ozone. The effects of UV/O3 comprehensive aging on the TPV compounds were evaluated by means of the variations of surface morphology, tensile test, hardness, gel content, and carbonyl index with aging time. On the basis of the aging behavior, we concluded that TPV/TiO2-KH570-MB exhibited excellent stability against UV/O3 aging, due to the homogeneous dispersion, low level of migration, and low volatility of TiO2-KH570-MB.