Effect of processing method on the shielding effectiveness of electromagnetic interference of MWCNT/PMMA composites

MWCNT/PMMA composites were prepared by in situ and ex situ methods. SEM microphotographs reveal that the MWCNT/PMMA composites that are prepared in situ adhere better than those prepared ex situ. MWCNT/PMMA composites prepared in situ exhibit a lower electrical resistivity and a lower percolation threshold than those prepared ex situ. The effects of the method of processing the MWCNT/PMMA, the MWCNT content and the composite stacking process on the shielding effectiveness (SE) of the electromagnetic interference (EMI) of the MWCNT/PMMA composites were examined. The SE of EMI of MWCNT/PMMA increased with MWCNT content. The composites prepared in situ have higher SE values. Additionally, composites prepared by stacking ten layers of 0.1 mm MWCNT/PMMA have a higher SE than that prepared from a single 1.0-mm-thick piece of bulk MWCNT/PMMA. The characteristic SE spectra of all systems were also discussed.