NOVEL FOUR-DIMENSIONAL PRINTING OF 3D-PRINTED ABS VIA ELECTRON BEAM IRRADIATION

Abstract

The proliferation of electronic devices has given rise to electromagnetic interference (EMI), which can cause malfunction in electronic devices and disrupt wireless communication systems. Polymers in their pure form exhibit limited EMI shielding properties due to their inherently low electrical conductivity. A promising approach to address this limitation is found in four-dimensional (4D) printing, which can manipulate the intrinsic characteristics of 3D-printed objects in response to external stimuli, such as electron beam (EB) irradiation. This paper investigated the effects of electron beam irradiation (0, 125, 250 kGy) on the thermal, electrical, and mechanical properties of 3D-printed ABS samples. In addition, it evaluates the influence of EB irradiation on the shielding effectiveness (SE). Both tensile strength and modulus showed a slight decrease with the increase of EB dosage. Contrarily, thermogravimetric analysis (TGA) results indicated an improvement in thermal stability with EB irradiation. EB irradiation causes polymer chains to undergo chain scission, where the polymer backbone is broken, leading to a decrease in the mechanical properties. While chain scission might reduce tensile strength due to a weakened polymer structure, it may simultaneously increase thermal stability because shorter polymer chains are less susceptible to degradation at elevated temperatures. Moreover, a slight increase in SE value at a certain frequency is observed in the EB irradiated 3D-printed ABS. The increase in SE might be attributed to the decrease in porosity due to formation of crosslinked networks induced by EB radiation. The findings suggest that both crosslinking and chain scission take place upon EB irradiation of 3D printed ABS in this particular dosage range. Most significantly, this study demonstrates a promising method for improving the properties of 3D printed ABS intended for use in EMI shielding applications.