Mechanical and fracture properties of hyperbranched polymer covalent functionalized multiwalled carbon nanotube-reinforced epoxy composites

• Published in: Chemical physics letters Vol. 706; pp. 31 - 39
• Main Authors: Wang, Lulu, Tan, Yefa, Wang, Xiaolong, Xu, Ting, Xiao, Chufan, Qi, Zehao
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 16.08.2018
• Subjects: Epoxy composites; HTDE; IFSS; Mechanical properties; MWCNTs; Toughening mechanism; Epoxy composites; Mechanical properties; MWCNTs; HTDE; Toughening mechanism; IFSS
• ISSN: 0009-2614; 1873-4448
• DOI: 10.1016/j.cplett.2018.05.071

[Display omitted] •HTDE was grafted on MWCNTs by covalent functionalization strategy.•The HTDE-g-MWCNTs are homogeneously dispersed in the epoxy matrix.•Interfacial shear stress enhancing and residual stress relieving improve property.•Main toughening mechanisms are pull-out and breakage of HTDE-g-MWCNTs. Using a covalent functionalization strategy, hyperbranched poly (trimellitic anhydride-diethylene glycol) ester epoxy resin (HTDE) was grafted on multiwalled carbon nanotubes (MWCNTs). Then the HTDE grafted MWCNTs (HTDE-g-MWCNTs) were used as toughener to prepare epoxy composites (HTDE-g-MWCNT/EP). The results show that the HTDE-g-MWCNTs are homogeneously dispersed in the epoxy matrix and the tensile strength and fracture toughness of HTDE-g-MWCNT/EP composites are enhanced. The property improvements are due to the enhanced interfacial shear stress and relieved internal residual stress. The main toughening mechanisms are pull-out, breakage of HTDE-g-MWCNTs, and their bridging effect to crack, and shear failure of epoxy matrix around HTDE-g-MWCNTs.