Smart Polymeric Foams Based on LDPE/EVA/MWCNT Nanocomposite:Correlation Between Micromorphology and Shape Memory Behavior

In the present work, smart shape memory polymer (SMP) foams were produced via melt-compressionmolding based on crosslinked blends of low-density polyethylene (LDPE) and ethylene-vinyl acetate(EVA) copolymer containing multi-wall carbon nanotube (MWCNT). For this purpose, blendcompounds with various phase ratios and corrosponding nanocomposites with differentconcentrations from MWCNT (۱.۵, ۲.۵ and ۴ phr) were prepared via melt-mixing process. Thepresence of MWCNT nano particles led to significant increase of cell density and decrease on cellsize in both LDPE-rich and EVA-rich generated foams, which revealed further micromorphologychanges in EVA-rich foams due to the more thermodynamically interest of carbon nanotubes andlocalization in EVA phase. Thermomechanical shape memory test exhibited a great shape memoryeffect (SME) obtained by ۴ phr MWCNT in LDPE-rich foam (%Rr=۹۸) and EVA-rich foam(%Rf=۹۶), which depicts elastic cell walls with higher cell density made by formation of MWCNTphysical networks above percolation threshold could enhance shape fixity and shape recovery of SMPfoams.

کلیدواژه ها:

Foams ، Smart Polymers ، Shape Memory ، MWCNT ، EVA