Structure and Performance of Carboxylic Styrene Butadiene Rubber/Citric Acid Composite Films

Abstract

Herein, we report rubber composite films which are fabricated via film formation of carboxylic styrene butadiene rubber (XSBR) latex and citric acid (CA) solution. CA is regenerated in the interstitial space between XSBR latex particles, forming various structures with increasing contents. Before the CA nanocrystals appeared, the XSBR/CA composite films exhibit healable characteristics because of the massive hydrogen bonds. When the CA content achieves 30 wt %, CA nanocrystals appear and are regularly arranged in the rubber matrix. Then, the CA nanocrystals serve not only as multifunctional cross-linkers via hydrogen bonding with XSBR but also as effective reinforcers to improve the mechanical properties of the composite films. As the CA content achieves 60 wt %, the CA nanocrystals grow to micron size, and the tensile strength of the XSBR/CA film is 7.83 MPa (about 4.1 times that of neat XSBR) and Young’s modulus is 31.2 MPa (almost 60 times that of neat XSBR). Interestingly, although the regenerated CA slightly decreases the T g of XSBR, the maximum shape-fixing temperature of XSBR/CA composite films increases to about 12–14 °C, which can program the shape memory behavior of the composite films. Moreover, because of the water-soluble nature of CA, the XSBR matrix can be recycled completely by soaking the films into water to remove the CA in a mild condition.

Multi‐copolymerization retouch butadiene styrene block polymer resin for dual temperature change curing of wood‐based interface

“…3026 cm −1 is the CH stretching vibration on the aromatic ring in polystyrene, and there is no change in the nearby bands under the four sets of comparisons, so it can be inferred that the aromatic ring does not participate in the whole reaction. XSBL‐0.33, XSBL‐1.00, and XSBL‐1.33 have large‐area broad peaks at 2000–2400 cm −1 , which are the stretching vibration regions of triple bonds, namely nitrile (CN), 6 967 cm −1 and near 911 cm −1 is the CH out‐of‐plane deformation vibration of 1,2 addition polybutadiene. Near 2919 cm −1 is the CH2‐up CH stretching vibration of butadiene, and the increase of its absorption peak proves the trace of single bond formed by olefin polycondensation, which also corresponds to the connection between active site 1 and active site 2 in Step 1 ;The above changes indicate the self‐condensation 11 of AN and HEA through unsaturated vinyl at high temperatures successfully grafted onto the Pb chain of the block polymer; The CH stretching vibration appears at 2846 cm −1 and the absorption peaks show a gradual shift towards lower wavenumbers with increasing doping due to the cross‐linking of the lipid groups, converting the methyl group to methylene to link the two macromolecular chains together, is also evidence of the presence of cross‐linking sites in step 2 .…”

“…With the introduction of carboxyl groups, the elastic range, strength, compatibility with functional fillers and polymers, hydrocarbon resistance, and solvent resistance are all enhanced, 5 and these features are highly valued in the industry for their good mechanical properties, elasticity, and wear resistance after plasticization. 6 However, the molecular chains in XSBL are extremely flexible and susceptible to loss of high activity due to external influences, resulting in a lack of adhesion to the adherent, which has limited its large-scale and widespread adoption. Therefore, in recent years, many investigations have been carried out to modify the traditional latex by physical filling and/or chemical cross-linking to promote the properties of XSBL resin.…”

“…Carboxy butadiene latex (XSBL) is a new ionic supramolecular hybrid network latex made by adding acrylic acid (AA) to the SBL chain. With the introduction of carboxyl groups, the elastic range, strength, compatibility with functional fillers and polymers, hydrocarbon resistance, and solvent resistance are all enhanced, 5 and these features are highly valued in the industry for their good mechanical properties, elasticity, and wear resistance after plasticization 6 . However, the molecular chains in XSBL are extremely flexible and susceptible to loss of high activity due to external influences, resulting in a lack of adhesion to the adherent, which has limited its large‐scale and widespread adoption.…”

Shape-Memory Composites Based on Ionic Elastomers

“…Weiss et al [ 26 , 27 ] designed elastomeric ionomers of sulfonated ethylene propylene diene rubber (SEPDM) with low-molar-mass fatty acids or their salts (e.g., zinc stearate). Xie et al [ 28 , 29 ] investigated the shape-memory properties of a thermoplastic polymer perfluorosulfonic acid ionomer (PFSA), Nafion™, with ionic clusters in a semicrystalline matrix, and Zheng et al fabricated rubber composite films, which are fabricated via the film formation of carboxylic styrene butadiene rubber (XSBR) latex and citric acid (CA) solution [ 30 ]. Salaeh et al also introduced the ionic network of a PVDF/XNBR blend by incorporating ZnO [ 31 ].…”

Fabrication of an Ultrastrong Formaldehyde-Free Wood Adhesive with an Organic–Inorganic Cross-Linking Network

“…It appears as a white, thick emulsion. , XSBR is widely applied across various industries owing to its exceptional cohesive strength, notable stability, and cost-effectiveness. It is used in tire manufacturing, cushion production, insulation materials, papermaking, and the construction industry. , Moreover, it is commonly employed in the adhesive industry as a dispersant in aqueous isocyanate wood adhesives. , However, its mechanical properties are limited by the presence of significant free space between molecular chains and weak intermolecular forces. , …”