Enhancement of mechanical strength associated with interfacial tension between barium titanate and acrylonitrile–butadiene rubber with different acrylonitrile contents by surface modification

Abstract

Acrylonitrile–butadiene rubber (NBR) with different acrylonitrile (ACN) contents was filled with barium titanate (BT) to prepare the polymer dielectrics. The neat NBR, NBR/untreated BT, and NBR/bis‐(γ‐triethoxysilylpropyl)‐tetrasulfide (silane coupling agent KH845‐4) modified BT (MBT) composites were prepared. At low ACN content (ACN content 20 wt %), the tensile strength of the NBR/MBT composites increased by 173.6% from 2.69 to 7.36 MPa compared to the neat NBR. The pleasing results were not found in those composites with high ACN content. Both surface modifications of BT and NBR with low ACN content would result in lower interfacial tension between BT and NBR. A strong interfacial adhesion was observed between MBT and NBR with 20 wt % ACN content. The interfacial adhesion had great contribution to the mechanical strength of composites. Moreover, the dielectric properties of composites were also investigated in detail. The addition of BT enhanced the dielectric constant of composites markedly. This study can be applied in manufacturing electronic devices, which are subjected to oily environments for a long time. At the same time, the study can provide some help for researchers to select the polymer matrix and the appropriate surface modification agent of functional filler. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45936.

Characterization of barium titanate reinforced acrylonitrile butadiene rubber composites for flexible electronic applications: influences of barium titanate content

“…Although the effect of different acrylonitrile contents and silane coupling modified BT on NBR filled BT has been described by Zhu et al, 11 the BT loading was not reported. While Amin et al 22 have presented the electrical properties of NBR/BT composites, many related details including cure characteristics, mechanical, dynamic mechanical, thermal and morphological properties have not been investigated.…”

“…10 Nevertheless, the lack of interactions between a polymer matrix and an inorganic filler causes agglomeration of the filler, resulting in poor mechanical properties of the final composite. 11 The ways to increase interactions between fillers with a polymer include modifying either the filler surfaces or the available polar groups of the polymers. 12 Thus, some studies have investigated modifying the BT [13][14][15][16][17] and the application of coupling agents 10,[18][19][20] to improve the compatibility of BT with a polymer matrix.…”

“…21 Besides, it also exhibits excellent oil and chemical resistance at a wide range of operating temperatures due to the molecular structure that contains strongly polar C≡N dipoles; these have the important characteristic of orientation polarization. 11 NBR was selected as the polymer matrix in this study. The incorporation of BT into NBR could overcome their weaknesses and provide composites with high dielectric constant and high flexibility.…”

Recent development on modification of synthesized barium titanate (BaTiO3) and polymer/BaTiO3 dielectric composites

“…[102] Like TPU, the endogenous heat of NBR generated during actuation is too large to shorten the its service life. [103] The main chains of silicone rubber are composed of silicon and oxygen atoms alternately. [104] Ordinary silicone rubber is mainly consisted of siloxane segments containing methyl and a small amount of vinyl.…”

“…[76] It is reported that commercialized coupling agents are effective in surface modification of BaTiO3 filled in elastomers, because coupling agents not only reduce the surface energy of particles, but also introduce functional groups to the surface of BaTiO3 particles, shown in Figure 9. [103,120] ( Figure 9) Figure 9 Reaction mechanism model among BaTiO3 (BT), silane coupling agent KH845-4 and molecular chain [103] As shown in Figure 10, such functional groups can participate into the vulcanization process to form extra crosslinks with polymer matrix, which improves the mechanical properties of composites. [120] ( Figure 10) with NDZ109 treated BaTiO3; (D) EPDM with KH570 treated BaTiO3; [120]…”