Epoxy nanocomposites filled with thermotropic liquid crystalline epoxy grafted graphene oxide

Abstract

Thermotropic liquid crystalline with epoxy groups grafted graphene oxide (LCE-g-GO) was synthesized by graphene oxide (GO), hexamethylene diisocyanate (HDI), and 4,49-bis-(2-hydroxyhexoxy) biphenyl (BP 2 ) by using pyridine and dibutyltin dilaurate as catalyst and dimethylformamide (DMF) as solvent. In this work, the LCE-g-GO nanosheets were characterized by Fourier transform infrared spectroscopy (FT-IR), wide angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), transmission electron microscopy (TEM) and polarizing optical microscopy (POM). The epoxy nanocomposites were fabricated by incorporating different LCE-g-GO loading using cast molding method. The results revealed that the incorporation of the LCE-g-GO resulted in a significant improvement in thermal and mechanical properties. The epoxy nanocomposite with 5 wt% LCE-g-GO produced an increase in the temperature for 5 wt% weight loss (T 5% ) by 47 uC and glass transition temperature (T g ) by 14 uC when compared with the neat epoxy. Moreover, at the addition of 5 wt% LCE-g-GO, the impact strength of the epoxy nanocomposite is 35.06 kJ m 22 , which is 2 times higher than that of the neat epoxy resin (17.49 kJ m 22 ). Meanwhile, the tensile strength of the nanocomposite is significantly increased to 92.5 MPa from 54.3 MPa, while the elongation at break is also increased to 42.9% from 25.7% of the neat epoxy, respectively. Therefore, the presence of the LCE-g-GO in the epoxy matrix could make epoxy not only stronger but also tougher.

Enhanced thermal and mechanical properties of epoxy composites by mixing thermotropic liquid crystalline epoxy grafted graphene oxide

“…The T max is 18°C higher than that of the neat epoxy resin when filler content is 1.0 wt%, and the specific data of thermal decomposition are summarized in Table 1.The significant improvement of thermal stabilities can be attributed to the layered structure of the composite, which causes tortuous pathway for the volatile degradation products, thus delays the decomposition rate of the whole composites Figure 6. WAXD patterns of GO and TLCP-g-GO, inset: photographs of GO and TLCP-g-GO [38,39]. At the same time, the filler surface and the matrix take place crosslinking by curing reaction, which restrict thermal motion of the polymer molecular and also improve the thermal stability of the polymer.…”

Enhanced thermal properties in a hybrid graphene–alumina filler for epoxy composites

“…These nanollers are deep embedded in the epoxy matrix suggesting that covalent bonding are formed among the epoxide groups, hydroxy groups and amine groups. 3,5,8,40 3.3. Thermal conductivity of epoxy composites Fig.…”

“…3,19,22 Aer that, 500 mg RGO dispersed in 20 ml chloroform solution under sonication for 30 min. And then, 500 mg LCPBI were added, followed by other 30 min of sonication.…”

“…[1][2][3][4] When it comes to the thermal dispersion problem, these resins cannot meet the requirements in the aerospace electrical and electronic components due to their poor thermal conductivity and weak resistance to high temperature. 5 Currently, aerospace devices are embedded with lots of electronics which generate considerable amounts of heat energy.…”

Properties and Morphologies of Epoxy Resin Based Composites Reinforced by Polyurethane and Graphene Oxide

“…Generally the modi cation process of EP with PU is conducted by reacting polyol and isocyanate rst to produce PU prepolymer terminated with isocyanate groups, then the PU prepolymer product is reacted with EP 5,6) . With the rise of nano science and technology, an increasing number of composites of EP and PU modi ed by graphene compounds have been reported, which are featured by enhanced mechanical property and excellent thermal stability [7][8][9][10][11] . Nevertheless, seldom study focused on the comprehensive in uence of PU prepolymer and graphene compounds on EP based composites.…”