Influence of the Surfactant on the Hydrotalcite Dispersion in NBR/LDH Composites Produced by Coagulation

Abstract

Summary Dispersions of 10% wt hydrotalcite were prepared by mixing using an ultrasound probe and then incorporated into NBR latex for the purpose of evaluating the influence of the surfactant presence and dispersion stability of the hydrotalcite, both in water and in latex. The surfactant used was Pluronic F‐127 and its influence was determined on the size of the agglomerates, the degree of sedimentation and the viscosity of water/LDH dispersions and latex/LDH suspensions. Preliminary results showed the efficiency of the surfactant in promoting dispersion of water/LDH, presenting lower agglomerate diameter values and increased stability of the dispersion. For the latex/LDH suspension, the viscosity of the system containing surfactant was significantly greater due to a better dispersion of LDH. After coagulation, the systems were examined in detail using X‐ray diffraction (XRD) and the results did not show differences in the degree of intercalation, but XRD pattern of LDH was not observed, indicating the breakdown of crystallinity and ordering of the clay crystallites. The ash content showed that the presence of surfactant was an important factor to optimize the incorporation of the clay during coagulation. The estimation of Payne effect from shear modulus indicated a better filler dispersion in NBR matrix when using Pluronic F‐127, this behavior was also confirmed by FESEM micrographs.

Tailoring Hybrid Layered Double Hydroxides for the Development of Innovative Applications

“…[70b,183] The resulting films display a well‐defined cellular microstructure leading to mechanical percolation behavior and an overall mechanical reinforcement. In a similar approach, nitrile rubber NR/LDH composites were also prepared by latex blending and coagulation . Dispersion stability was ensured by pluronic F‐127 addition acting as a dispersing agent, together with the use of ultrasound in order to decrease particle size and aggregation.…”

Systematic Literature Review of the Effect of Layered Double Hydroxides on the Mechanical Properties of Rubber

“…The effect of using the surfactant Pluronic F-127 on the dispersion of Mg-Al LDH in NBR latex was investigated by Braga et al [109]. The LDH adsorbed the hydrophilic groups of the surfactant through hydrogen bonding and the hydrophobic groups of the surfactant then acted as a barrier between LDH particles.…”

“…The four studies in which PU/NBR blends were used were summarised in Table 4 and are repeated here. The study by Braga et al [109] is not summarised here as mechanical property data were not reported. HNBR is made by removing double bonds in the backbone chain of NBR, which makes it more resistant to oxidation than NBR and improves the tensile and tear strength [120].…”

Aging-Resistant Functionalized LDH–SAS/Nitrile-Butadiene Rubber Composites: Preparation and Study of Aging Kinetics/Anti-Aging Mechanism

“…In addition, organically modified LDHs can also be applied to rubber composite materials [ 39 ]. NBR has similarly been modified with LDHs to improve its mechanical, thermal and optical properties [ 32 , 40 , 41 , 42 , 43 , 44 , 45 ], with just previous one report on the influence of LDHs on the thermal oxidative aging resistance in NBR materials existing in the literature [ 7 ]. NBR complexes using modified LDHs have also been prepared to improve mechanical properties.…”