Mehmet Kodal

Micro and Nanofillers in Rubbers

As a most general definition, filler is a finely divided solid that is used to modify the properties of a material in which it is dispersed. From the inception of the rubber industry, fillers have a crucial role in either providing durability and performance or in reducing the price by decreasing the rubber partition in the compound. The fillers used in rubbers can be divided into two main groups such as black and non-black fillers. Besides the conventional micron size fillers, nanofillers recently have gained both academic and industrial importance. In this chapter, it is aimed to introduce the fillers used in rubbers. Their characteristics and their impact on properties of rubbers are discussed by giving examples from the recently published literature. In addition to the conventional ones, the new emerging nano-fillers and their added value to the rubbers are given in detail by highlighting some selected studies.

Effects of epoxy-POSS nanoparticles on the properties of PLA/TPU blends

In this study, the influence of epoxy functionalized polyhedral oligomeric silsesquioxanes (G-POSS) loading level on the mechanical, thermal and rheological properties of poly(lactic acid) (PLA)/thermoplastic polyurethane (TPU) blends were investigated. The blends were prepared in an Xplore Instruments MC15 twin-screw microcompounder at 200°C barrel temperature and 100 rpm screw speed. Mechanical properties were characterized by tensile and impact tests, thermal properties were determined via differential scanning calorimeter (DSC) and thermogravimetric analysis (TGA). Rheological properties were examined by oscillatory rheometer. A decreasing trend in tensile strength and thermal degradation temperature were obtained for PLA/TPU blends at high G-POSS loading levels. G-POSS loading level did not exhibit significant effect on glass transition, crystallization and melting temperatures of the blends.

Correlation between crystallization behaviour and interfacial interactions in plasticized PLA/POSS nanocomposites

In this study, the correlation between crystallization behavior and surface chemistry of polyhedral oligomeric silsesquioxanes (POSS) for plasticized poly(lactic acid) (PLA)/POSS nanocomposites was investigated. Four different kinds of POSS particles having different chemical structures were used. Poly(ethylene glycol) (PEG, 8000 g/mol) was utilized as the plasticiser. The nanocomposites were melt-compounded in an Xplore Instruments 15 cc twin screw microcompounder at 180°C barrel temperature and 100 rpm screw speed. Non-isothermal crystallization behaviour of PLA/PEG/POSS nanocomposites were evaluated from common kinetic models such as Avrami and Avrami-Ozawa and Kissinger by using the thermal data obtained from differantial scanning calorimetry (DSC). A polarized optical microscope (POM) equipped with a hot-stage was used to examine the morphology during the crystal growth. In order to investigate the interfacial interactions between POSS particles and plasticized PLA, thermodynamic work of adhesion app...