Enhanced Anticorrosion Properties through Structured Particle Design of Waterborne Epoxy-Styrene-Acrylate Composite Emulsion

In order to develop a waterborne epoxy-styrene–acrylate composite latex with a better stability and anticorrosion resistance, a novel synthetic approach has been proposed. First, modified by methyl acrylic, epoxy resin containing terminal C=C double bonds was successfully synthesized, where epoxide groups were partially retained. Then, by structural design and multi-stage seed emulsion copolymerization, a stable waterborne epoxy-styrene-acrylate composite latex composed of a modified epoxy resin acrylate polymer as the core, inert polystyrene ester as the intermediate layer, and carboxyl acrylate polymer as the shell was successfully fabricated. The structure of the obtained latex was characterized by fourier transform infrared (FTIR) and transmission electron microscopy (TEM). The stability of the composite latex was tested based on the wet gel weight, Zeta potential, and storage stability, and the corrosion resistance of the composite latex films was analyzed by electrochemical measurements and salt spray tests. The thickness of each layer of the composite latex was calculated by the temperature random multi-frequency modulation DSC (TOPEM-DSC) technique. In addition to the successful emulsion copolymerization that occurred between the modified epoxy resin and acrylate monomer, the presence of carboxyl groups in the obtained latex was evidenced, while the epoxide groups were partially retained. The anticorrosion resistance and stability of the multilayer composite latex with the intermediate layer are better than that of the conventional core-shell latex. The outstanding stability and corrosion resistance is attributed to the multilayer core-shell structure. The TOPEM-DSC approach can accurately determine the thickness of the intermediate layer in the multilayer core-shell particles and is a new strategy for characterizing the core-shell structure of polymer particles with a similar monomer composition.

Toughness Behavior of SBR Acrylate Copolymer-Modified Pervious Concrete with Single-Sized Aggregates

Pervious concrete is an eco-efficient concrete but has problems regarding its mechanical performance and permeability balance. This research investigated the feasibility of using a combination of styrene–butadiene rubber (SBR) and acrylate polymer to improve the toughness of pervious concrete while keeping its permeability. Single-sized aggregate and no sand were considered in the concrete mixture. Acrylate polymers with different solid content, PH, density, and viscosity were emulsion copolymerized with an SBR polymer. Eleven scenarios with different mix proportions and 220 specimens for compressive strength, flexural strength, flexural stiffness, impact resistance, and fracture toughness tests were selected to evaluate the effects of the copolymer on the toughness of copolymer-modified pervious concrete (CMPC). The studies showed that (1) the influence trend of the copolymers generally varied according to different mechanical indexes; (2) XG–6001 acrylate polymer mainly and comprehensively enhanced the toughness of the CMPC; (3) it was difficult to increase the enhancing property of the XG–6001 acrylate polymer with the growth of its mix proportion; (4) the zero-sand pervious concrete with 90% SBR and 10% XG–6001 acrylate emulsion copolymerization proved to have relatively high toughness. The proposed CMPC holds promising application value in sustainability traffic road construction.

Interfacial Effects and the Nano-Scale Disruption in Adsorbed-Layer of Acrylate Polymer-Tween 80 Fabricated Steroid-Bearing Emulsions: A Rheological Study of Supramolecular Materials

The effect of polymer adsorption on the stability and viable shelf life of 55 μm diameter oil-in-water (O/W) emulsions containing the steroid, betamethasone 21-phosphate was investigated. Two acrylate polymers, Carbopol® 971P and 974P, were added in the role of emulsion stabilizers to a model system, representing a non-ionic low molecular weight surfactant-stabilized emulsion (topically applied medicinal cream). For the purposes of this study the dosage of the viscosifier was maintained below 1% w/v and consequently, the consistency of the emulsion was measured in the diluted form. One of the polymers was responsible for elevated degrees of droplet creaming and coalescence and this was closely linked to its surface tension lowering capacity. This lowering was seen at 62 mN/m compared to the routine values at equivalent concentrations of 68 mN/m and 35 mN/m for the betamethasone drug and non-ionic surfactant-Tween 80, respectively. The same polymer also demonstrated a predisposition to form low-micron and greater sized aggregates of nanoparticles that led to extensive flocculation and the formation of a sedimentary precipitate, formed from an amalgam of the components found in the creamed droplet layer.