Journal of Applied Polymer Science最新文献

One-pot epoxy formulations, containing uncured resin, curing agent, and promoter, require the promoter to be insoluble in the resin at room temperature to prevent premature polymerization. Here, we introduce three novel reaction promoters synthesized by reacting amino propyl imidazole (API) and various diisocyanates such as HMDI, IPDI, or MDI. We evaluate the impact of these promoters on the physical properties, storage stability, and curing kinetics of the resulting epoxy formulations. The results of the kinetic study showed that the compositions containing each synthesized promoter acted as reaction promoters, as evidenced by the lower activation energy in the differential scanning calorimetry (DSC) experiment. The results of the mechanical properties showed that HMDI-API promoter improved both tensile and flexural strength, while exhibiting high storage stability. The findings provide valuable insights for selecting suitable promoters for specific applications in one-pot epoxy systems.

S. Sunder, M. Jauregui Rozo, S. Inasu, B. Schartel, H. Ruckdäschel, J. Appl. Polym. Sci. 2024, 141(39), e55988. https://doi.org/10.1002/app.55988 .

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Epoxy cross-linked coatings are widely used to protect and beautify many surfaces all around us. However, these coatings possess a dense carbonaceous structure, rendering them susceptible to ignition, spread, and propagation of flames. Therefore, flame-retardant (FR) materials are added into these coatings as additives to improve flame resistance properties. Many of the commercially available FR additives are halogenated, metal oxide, and alkyl phosphate-based compounds, often originating from nonrenewable resources. Some of these compounds produce undesirable toxic fumes and byproducts upon combustion. To overcome these challenges, we tested bio-based phytic acid (PA) as an FR additive in epoxy resin, cross-linked with bio-based phenalkamine (NX)—a material derived from cashew oil nutshell. Our findings demonstrate that the incorporation of PA into an NX-cross-linked epoxy coating system significantly enhances the FR properties of the coatings while preserving their physico-mechanical characteristics such as solvent resistance and hardness. Additionally, the inclusion of PA markedly enhances the FR performance of the coatings by reducing flame spread rate, minimizing dripping, and suppressing ignition temperature. Moreover, upon addition of 10% w/w PA increases the ignition time, decreases peak heat release rate (PHRR) by more than 25%, reduces total heat release (THR) by the similar amount, and suppresses total smoke production by >40% compared to the coatings containing FR- agents based on metal oxides and alkyl phosphates. Our work clearly demonstrates the feasibility of using PA as the FR additive for producing eco-friendly and low-flammable epoxy cross-linked coatings.

A multi-template molecularly imprinted photocatalyst based on Black TiO₂ was used for selective and simultaneous adsorption and degradation of Non-steroidal anti-inflammatory drugs (NSAIDs) under LED irradiation from aqueous solutions. diclofenac (DCF) and ibuprofen (IBP) were chosen as the target chemicals and the performance of the Black TiO₂-MIP nanocomposite in removing these pollutants was investigated. The imprinting procedure was confirmed by characterization tests of the nanocomposite. The synthesized mesoporous nanocomposite exhibited excellent fit with the pseudo-second-order kinetic model (R² ≥ 0.99). Moreover the experimental data demonstrated a good fit with the Langmuir isotherm model (R² = 0.99). The findings imply that the binding sites are homogeneous and indicate monolayer chemical adsorption on the adsorbent. Toxicity assessment of targeted chemicals and their by-products, worked out using the Ecological Structure–Activity Relationships (ECOSAR) program, revealed a significant decrease in the toxicity of the target compounds during photocatalytic degradation. In addition, the use of Black TiO₂-MIP nanocomposite in the cartridge structure led to notable removal efficiencies, 98.7% and 97.6% for DCF and IBP, respectively. The findings also provided evidence that the use of Black TiO₂-MIP in the cartridge structure not only facilitated the removal of target pollutants but also addressed challenges related to the collection and separation of the nanocomposite from the aqueous solution. The results implied that the integration of molecular imprinting and photocatalysis processes exhibits high effectiveness in the simultaneous and selective removal of contaminants. This approach holds promise as an effective solution for addressing the challenge of drug residues in aqueous samples.

Nanoparticle (NP) enabled approaches have been employed for chemotherapeutic administration due to their capacity to regulate drug release and reduce side effects. Additionally, these methods can use several drugs concurrently and impede the proliferation of cancer cells that have developed resistance. Bevacizumab (BVZ) and pemetrexed (PEM) have demonstrated encouraging outcomes in the treatment and management of cancer. This work investigates the combined antiproliferative efficacy of BVZ and PEM co-loaded PLGA-PEG NPs (BVZ/PEM@PLGA-PEG NPs) against HepG2 liver cancerous cells. The BVZ/PEM@PLGA-PEG exhibited a sphere-shaped and consistent nanosized distribution. In addition, we evaluated the potential mechanisms for inhibiting cell growth and inducing apoptosis using DAPI staining and cell cycle study. The beneficial combined antiproliferative activity and the apoptosis pathway were detected in the HepG2 cells exposed to BVZ/PEM@PLGA-PEG NPs. Our study determined that the combinational drug treatment of BVZ/PEM@PLGA-PEG NPs has a significant effect on promoting the effectiveness of liver cancer treatment.

As a representative of dope-dye, the color masterbatch method has been widely applied in modern dyeing processes, while it has difficulties in solving the dispersibility of inorganic pigments color master batch in the polymer matrix. In this work, attapulgite (ATP) was used as the adsorption carrier of inorganic pigments to prepare color-dyed attapulgite (CD-ATP). The selected environmentally friendly inorganic pigments were well adsorbed by ATP in KOH aqueous solution, and could stably be monodispersed in KOH aqueous solution for more than 168 h. Moreover, the KOH aqueous solution could be reused repeatedly, thereby, a sustainable method to prepare novel CD-ATP was realized. By blending the as-prepared CD-ATP with polyamide-6 (PA6), a series of dope-dyed colorful PA6 composites was prepared. Scanning electron microscope (SEM) results indicated that the CD-ATP was still monodispersed in the PA6 matrix, and endowed PA6 with a vivid color. Further studies show that the adding of CD-ATP had little influence on the properties of PA6, but significantly reduced the water adsorption. This novel color-dyed ATP has potential implications in making paper-making blankets and is highly expected to have more extensive applications in many fields of life.

In this study, five compounds belonging to the Polymer composites (PCs) family, have been prepared with different amounts of polyacrylonitrile and polyindole in the composite. The PCs have inherently bactericidal activity, owing to the nitrile and indole groups. Antioxidant activity was assessed by using reducing power activity, superoxide radical scavenging activity and hydroxyl radical scavenging activity. In our study, butylated hydroxy toluene (BHT), ascorbic acid and α-tocopherol, which are considered synthetic standard antioxidants, were used to compare antioxidant activity. In addition, since it is known that the MDA levels resulting from the oxidation of fats in Saccharomyces cerevisiae yeast cells are inversely proportional to the antioxidant properties, it gave an idea about the in vitro antioxidant properties of the new synthesized PCs. Reducing force capacity, superoxide radical scavenging activity and hydroxyl radical scavenging activity were found to be higher at 100 μg mL⁻¹ concentration compared to 50 μg mL⁻¹ concentration.

The difficult recycling and degradation in cured epoxy resins can be solved by introducing dynamic covalent bonds. However, the introduction of dynamic bonds degrades the properties of epoxy resins. In this paper, the dual-cured epoxy resin with high mechanical properties and high healing efficiency were obtained by constructing interpenetrating networks (IPNs). The effect of IPNs on the recyclability of epoxy resins was investigated. The performance is as follows, the flexural and tensile strengths is 89 and 54.2 MPa, respectively, and the breakdown strength is 32.5 kV/mm. In addition, the recyclability and high healing efficiency of the dual-cured epoxy resin were verified, and the effect of the hot-pressing temperature and time on the properties of the recycled samples were investigated. Under certain hot-pressing conditions, the flexural and tensile strengths of the recycled samples were recovered to 95.06% and 85.28%, respectively, and the breakdown strength was recovered to 83.6%.

Poly(3,4-ethylene dioxythiophene) (PEDOT) is a conducting polymer that can be used in flexible bioelectronic devices. The electrode/electrolyte interface interaction is one of the most important factors in improving the electrochemical performance of energy storage materials, and these polymers are often combined with a negatively charged poly(styrene sulfonate) (PSS) chain to improve their interaction with alkali metal cations such as sodium and potassium. In this work, we performed a one-step electrochemical synthesis of PEDOT on carbon fabric using the molecule 2-acrylamido-2-methyl-1-propane sulfonic acid (AMPS) to create highly effective materials for supercapacitor electrodes. The electrode had a significant increase in capacitance value, measured 16.4 times higher than that of the PEDOT electrode. The 2-electrode system exhibited a specific capacitance value of 495.2 F g⁻¹ at a scan rate of 5 mV s⁻¹. It exhibited a high operating voltage of 2.3 V in aqueous electrolyte system. It showed a significant energy density of 109.0 Wh kg⁻¹ when operating at 6.1 kW kg⁻¹ power density and 85.2 Wh kg⁻¹ when operating at 30.6 kW kg⁻¹ power density. Recent findings reveal that the capacitance retention performance value of the device increased significantly to 113.9% after 25,000 cycles in 3.0 M NaCl aqueous electrolyte, demonstrating its outstanding long-term durability. Thus, the creation of the synthesized supercapacitor electrode is a significant advance in the study of conducting polymers, which often have a limited lifetime in real-world electronic applications.

In response to the pressing need for effective removal of heavy metals from water sources, this study focuses on the optimization of Thin Film Composite nanofiltration membranes, known for their porous polymer support and selective ultrathin layers. The objective was to enhance the rejection of heavy metal ions, a critical issue in water treatment. The parameters of the interfacial polymerization (IP) process, including monomer concentration, reaction time, curing temperature, and curing duration, were tailored to determine the most effective membrane configuration. Polyimide (P84) was employed as the support material, with the IP involving trimesoyl chloride (TMC) and piperazine (PIP). Comprehensive characterization through Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), and water contact angle measurements provided information on the functional groups, surface and cross-sectional morphologies, and hydrophilic properties of the membranes. The optimized fabrication conditions, involving 0.2 w/v% TMC and 2.0 w/v% PIP monomer concentrations, a 2-minute IP reaction time, and a 40°C curing temperature for 10 minutes, led to the membranes achieving arsenic and chromium rejections of 89.7% and 99%, respectively. This was accomplished while maintaining a high pure water permeability of approximately 16.9 Lm⁻²h⁻¹bar⁻¹. These promising results highlight the potential of these optimized nanofiltration membranes for industrial applications, addressing a critical environmental challenge.