Enhanced mechanical properties of styrene–butadiene rubber with low content of bacterial cellulose nanowhiskers

Abstract

Styrene-butadiene rubber (SBR) nano-composites were prepared through mixing SBR latex with bacterial cellulose whiskers (BCWs). BCWs were extracted from the residual bacterial cellulose (BC) that was treated with acid hydrolysis. A rod-like nanofiber structure of BCWs was observed by transmission electron microscopy and atomic force microscopy. BCWs maintained the crystal structure in BCWs/SBR nano-composites as confirmed by X-ray diffraction patterns. The dispersion of BCWs in SBR matrix was further detected with field emission scan electron microscope.BCWs acted as a multifunctional physical cross-linker in the SBR matrix, the combination of BCW reinforcement and increased effective cross-linking density of the rubber network with incorporating BCWs would cause a more effective transfer of stresses from matrix to filler. Compared with neat SBR, the tensile strength and tear strength of SBR/BCW nano-composite with 2.5 phr (parts per hundred rubber) BCWs were increased by 319% and 182%, respectively. K E Y W O R D Sbacterial cellulose whisker, mechanical properties, styrene-butadiene rubber

Stimuli‐responsive polymer nanocomposites based on styrene‐butadiene rubber and bacterial cellulose whiskers

“…In the spectrum of SBR, the measured vibration bands are well assigned according to previous literatures . The bands at 2916 and 2843 cm −1 are ascribed to C─H asymmetric and symmetric stretching vibrations of ─CH 2 groups, respectively . The band at 964 cm −1 is assigned to the trans ─CH═CH─ vibrations of butadiene in SBR.…”

“…The tensile strength and tear strength of XNBR filled with 11 wt% of BCWs were increased by almost 321% and 155%, respectively, compared to that of neat XNBR. We also found that the introduction of BCWs resulted in prominent improvement in the mechanical properties of SBR …”

“…The acid hydrolysis treatment removes the amorphous regions of BC, while the crystalline parts are retained to form the slender rod‐like nanowhiskers (Figure C) . Owing to the strong hydrogen bonding interaction among surface hydroxyl groups, BCWs tend to connect with each other, as shown in Figure C . The height profile of nanowhiskers shown in Figure D suggests that BCWs have diameters between 3 and 30 nm.…”

Water‐induced mechanically adaptive behavior of carboxylated acrylonitrile‐butadiene rubber reinforced by bacterial cellulose whiskers

“…In the FTIR spectrum of BCWs, the dominating signal displays at 3,100–3,600 cm −1 , corresponding to the O‐H stretching vibration . The sharp and strong peak located at 3,344 cm −1 is ascribed to the intermolecular hydrogen bonds . The signature peak at 2,896 cm −1 is due to the C‐H stretching vibration of ‐CH 2 group in the side chain of cellulose, which suggests the intermolecular hydrogen bonds between cellulose chains .…”

“…Furthermore, the ultrafine three‐dimensional structure and sufficient water holding capability make BC more popular in biomedical field, compared with celluloses from other sources . Bacterial cellulose whiskers (BCWs), a derivative of BC prepared by acid hydrolysis of BC to remove the amorphous domains, is elongated crystalline rod‐like and possess higher crystallinity and higher aspect ratio (up to 100), which induce more conspicuous reinforcement effect for polymer matrix . In our previous work, carboxylated acrylonitrile‐butadiene rubber (XNBR)/BCWs vulcanizates were fabricated by mixing BCWs suspension with XNBR latex, followed by coagulating and vulcanization.…”