Abstarct: The purpose of this thesis is to study and investigate the mechanical properties and thermal resistance of polymer materials by making nanocomposite materials and using nanomaterials as a filler phase. In this study, by adding surface-modified nanoclay to polylactic acid, the changes in mechanical properties and thermal resistance of nanocomposites produced by bioprinter were investigated. For this purpose, samples of neat polylactic acid, polylactic acid/ (1 wt% nanoclay), polylactic acid/ (3 wt% nanoclay), polylactic acid/ (5 wt% nanoclay) were studied. In order to achieve a uniform dispersion of surface modified nanoclay in the field of polylactic acid, an internal polymer mixer was used. Tensile strength, Young's modulus and absorbed energy per unit volume until the moment of failure were extracted from the stress-strain curve. Vicat softening point test, tensile test at room temperature and 45 °C, and field emission scanning electron microscope test were performed to check mechanical properties and thermal resistance. The results of the Vicat softening point test in laboratory samples showed that the softening point in the reference samples without nanofiller is higher than the nanocomposite samples, and the softening point decreases as the percentage of surface modified nanoclay in the polylactic acid matrix increases. After obtaining the softening point in the reference sample, without nanofillers and nanocomposites, the required temperature for the high temperature environment tensile test was determined, and its value was considered to be 45 °C. In the tensile test related to room temperature and 45 °C, the tensile strength of the reference samples was higher than the nanocomposite samples. In the tensile test with increasing temperature, the tensile strength related to the tensile test at room temperature decreased compared to the tensile test at 45 °C in the reference samples, without nanofiller and nanocomposite. The results showed that in nanocomposites containing 1% by weight of nanoclay, the modified surface does not show the characteristic baxse reflection of nanoclay, but in nanocomposites containing 3% and 5% by weight, the effect of nanoclay can be well interpreted. Also, the Young's modulus and energy absorbed per unit volume until the moment of failure of the reference sample without nanofiller in the tensile test at room temperature and 45 °C were higher than the nanocomposite samples. The results of field effect scanning electron microscope images showed that the production of laboratory samples by bioprinter creates air holes in all samples. This reduced the final strength in the laboratory samples. In the sample containing 1% by weight of surface-modified nanoclay, smaller amounts of air bubbles were observed, which increased the final strength. Also, in the sample containing 5% by weight of modified nanoclay, lumpiness of nanoparticles was observed, which can be concluded that the creation of these lumpiness causes stress concentration and reduction of fracture strength.