Study on the effect of layered double hydroxide on the mechanical and thermal properties of nitrile butadiene rubber

Abstract

Nitrile rubber is a widely used rubber, so its basic mechanical properties are very important. In order to improve the mechanical properties of nitrile butadiene rubber (NBR), Mg-Al hydrotalcite was introduced into NBR by mechanical blending and hot pressing, and the mechanical properties of the composites were studied. The results show that, compared with NBR, the maximum M H -M L of 2%LDH/NBR composites reaches 1.795 NÁm, and an is improved by 8.7%. The T 90 of NBR and 2%LDH/NBR composites insignificant changed. In terms of mechanical performance, the optimal performance is achieved when two parts of layered double hydroxide (LDH) are added. Compared with the original NBR, the tensile elongation at break, tear strength, and 100% modulus stress increased by 11.6%, 7.1%, and 29.1%, respectively. The addition of LDH also has a certain influence on the thermal conductivity of the composites. Compared with the original NBR, the peak thermal conductivity of NBR with two parts of LDH increased by 2.4 mW. Under the condition of low filling, the mechanical properties such as elongation at break and tear strength of LDH/NBR composites have been improved, which provides a reference for the development of mechanical properties research of NBR.

Effect of Graphene Oxide-Modified CaAl-Layered Double Hydroxides on the Carbon Dioxide Permeation Properties of Fluoroelastomers

“…The mechanical properties of the nanocomposites were significantly improved compared with those of FKM, and interestingly, the ε b of the nanocomposites gradually increased with the content of nanofillers, in which the largest ε b (ε b > 287%, σ b > 11.1 MPa) value was obtained for the 10 phr filled FKM/GO/LDH-Ca 2 Al nanocomposites. This finding can be attributed to the orientation arrangement of the nanofillers with two-dimensional layered structures in the complexes when subjected to force, leading to the stable transfer of stress inside the material [9]. In addition, FKM/GO/LDH-Ca 2 Al nanocomposites exhibit superior mechanical properties to FKM/LDH-Ca 2 Al nanocomposites, in which σ b , and ε b increased by approximately 25% and 12% (Table 5) because of the strong interfacial interaction between GO/LDH-Ca 2 Al and the polymer matrix, which promotes the efficient transfer of stress from the polymer matrix to GO/LDH-Ca 2 Al, consistent with the results described by the phenomenological interaction parameters (Table 3) [19].…”

“…More importantly, the strong interface between the nanoparticles and the rubber molecules is significant in limiting chain migration and further reducing the free volume between the nanoparticles and the rubber molecules. Among a range of nanoparticles, layered particles such as layered double hydroxides (LDH) [7][8][9] and graphene (GE) or graphene oxide (GO) [10,11] have higher aspect ratios than spherical and fibrous particles, making them more conducive to enhancing the gas barrier properties of rubber composites [12]. In particular, LDH is considered to be a promising CO 2 adsorbent because of its controllable layer spacing and pro-CO 2 properties [13].…”

“…However, the thermal stability of LDH is poor, and it starts to undergo layer structure destruction at approximately 250 • C [18]. Most importantly, LDH is a polar inorganic material with limited compatibility with organic macromolecules such as natural rubber (NR), fluorine rubber (FKM), and nitrile rubber (NBR), leading to agglomeration in the polymer and the formation of weak phase interfaces [8,9]. Therefore, the dispersion and thermal stability of LDH in polymers can be improved by forming a compound with LDH along with new components.…”