Lap shear strength and thermal stability of diglycidyl ether of bisphenol a/epoxy novolac adhesives with nanoreinforcing fillers

Abstract

Nanoreinforcing fillers have shown outstanding mechanical properties and widely used as reinforcing materials associated to polymeric matrices for high performance applications. In this study, a series of multiwalled carbon nanotubes (MWCNTs)-, nano-Al 2 O 3 -, nano-SiO 2 -, and talc-reinforced epoxy resin adhesives composites were developed. The influence of different types and contents of nanofillers on adhesion, elongation at break, and thermal stability (under air and nitrogen atmospheres) of diglycidyl ether of bisphenol A (DGEBA)/epoxy novolac adhesives was investigated. A simple and effective approach to prepare adhesives with uniform and suitable dispersion of nanofillers into epoxy matrix was found to be mechanical stirring combined with ultrasonication. Transmission electron microscopic and scanning electron microscopic investigations revealed that nanofillers were homogeneously dispersed in epoxy matrix at optimized nanofiller loadings. Adhesion strength was measured by lap shear strength test as a function of nano-Al 2 O 3 and MWCNTs loadings. The results indicated that the lap shear strength was significantly increased by about 50% and 70% with addition of MWCNTs and nano-Al 2 O 3 up to a certain level, respectively. The highest lap shear strength was reached at 1.5 wt % of nano-Al 2 O 3 loading. MWCNTs at all loadings (except 3 wt %) and nano-Al 2 O 3 have enhanced onset of degradation temperature and char yield of the adhesives. By combined incorporation of 0.75 wt % nano-Al 2 O 3 and 0.75 wt % MWCNTs into the epoxy novolac/DGEBA blend adhesives a synergistic effect was observed in the thermal stability of the adhesives at high temperatures (800 C).

Effect of using multiwall carbon nanotube reinforced epoxy adhesive in enhancing glass fiber reinforced polymer composite through cocure manufacturing technique

“…Thus, it made them incompatible for composite part joining. In a study, Mansourian et al [47] incorporated CNT into the epoxy resin to enhance single-lap joints' shear strength. The outcome of their work revealed The failure surface of the cocured composite under shear load is shown in Figure 10.…”

Epoxy‐based composite adhesives with improved lap shear strengths at high temperatures for steel‐steel bonded joints

“…When novolac epoxy contents in adhesive formulations were greater than 20% (w/w), the wetting capability of the resin on the silica filler might decrease, resulting in an aggregation of micrometer-sized silica particles and reduced lap shear strengths of epoxy composite adhesives. [36] Therefore, the DN 80/20 resin composition was selected for further investigation with various silica filler contents.…”

Hekzagonal Bor Nitrür Nanoplate-Nano Ag/Epoksi Kompozitler: Üretimi, Mekanik ve Termal Özellikleri

“…Mansourian-Tabaei, Jafari [13] nano takviye dolgu malzemeleri üstün mekanik özelliklere sahip ve yaygın olarak yüksek performanslı uygulamalar için polimer matrisler ile ilişkili malzemelere takviye olarak kullanmışlardır. Bu çalışmada, çok cidarlı karbon nanotüpler (ÇCKNT) [14], nano Al 2 O 3 [15], nano SiO 2 [16] ve talk takviyeli epoksi reçineli yapıştırıcılar geliştirilmiştir.…”