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Metal oxide nano additives are widely used as a second phase modifier as they improve the properties of the matrix materials. Nano additives also supply various advantages for polymers which can be employed in additive manufacturing methods. Among the additive manufacturing methods, stereolithography is one of the most remarkable to produce nano-modified polymers because of the easy nano modification of the photocurable resins. In the present study, we mixed the metal oxide particles; Fe 2 O 3 , ZnO, NiO, Al 2 O 3 , TiO 2 , and MgO with the photocurable epoxy and used the mixtures to print the specimens. We investigated the structural morphology, thermal and mechanical properties of the printed specimens with an optical microscope, scanning electron microscope, Fourier transform infrared spectroscopy, differential scanning calorimeter, differential thermogravimetric analysis, and microhardness, respectively. Findings proved the dilute agglomeration of the nano additives. Besides, nano additives can improve the thermal stability of the photo-cured polymer. The microhardness of the Fe 2 O 3 added polymers reached 27.63 HV levels while it was measured as 16.16 HV for the pristine samples (~70% raise was experienced). The maximum degradation temperatures of the polymer nanocomposite structures were measured in the range of 396-420 C.

Three types of carboxyl‐functionalized multi‐walled carbon nanotubes (MWCNTs) were used to manufacture MWCNT‐modified laminates. The effects of the MWCNTs on the mode I interlaminar fracture toughness and the fracture propagation were investigated experimentally. Fractured surfaces were inspected with SEM micrographs to justify the effects of MWCNTs on the mode I fracture of the laminate. The short‐thin MWCNTs in a weight ratio of 0.3% increases mode I interlaminar fracture resistance of the laminate by about 2 times. The effects of long‐thin and long‐thick MWCNTs are quite low. Polymer crazing is the most important mechanism to improve interlaminar fracture properties.

In this study, mode I critical strain energy release rate (G Ic) of unidirectional E-glass/epoxy was determined by double cantilever beam (DCB) test. Calculated G Ic was used to initiate delamination in numerical models. The effect of stacking sequence and fiber orientation of the sublaminates and the effect of thickness on mode I delamination crack length and G Ic distribution along the specimen width in 0 o //0 o interface have been studied using ANSYS ®. 3-D 8-node linear interface element INTER 205 is used to create a predefined crack path. To investigate the fiber orientation effect, composites with [+θ 2 , 90 2 ,-θ 2 , 0 2 ] s stacking sequences were modeled. Interlaminar fracture analyses were performed by Virtual Crack Closure Technique (VCCT). Experimental and numerical critical loads (P cr) showed a good agreement. According to the results, while fiber orientation affects significantly the extended crack length and the G Ic distribution along the specimen width, stacking sequence only affects the G Ic distribution.