Preparation of high‐density polyethylene/montmorillonite nanocomposites with high gas barrier by micro‐nano torsional laminated extrusion

Polymethyl methacrylate (PMMA) with varied compositions of copper oxide (CuO) nanoparticles was synthesized using in‐situ free radical polymerization. UV–visible, FT‐IR, XRD, FE‐SEM, DSC, and TGA were employed to examine their structure, morphology, and thermal properties. The broadening and intensification of UV absorption, as well as the shift in IR peaks of PMMA with the addition of CuO, confirm their interactions. The reduction in optical bandgap values with the reinforcement of nanofillers confirms the existence of intermediate energy bands in nanocomposites. XRD indicated that polymerization with CuO reduced the amorphous nature of PMMA. The FE‐SEM image revealed that the dispersion of CuO altered the nonporous, rough surface of PMMA into a homogeneous shape. The reinforcement of CuO enhanced the thermal stability and glass transition temperature of PMMA. The mechanical strength, modulus, impact strength, and rigidity of PMMA were significantly improved through in‐situ polymerization. The electrical property analysis revealed that the AC conductivity increased with frequency, temperature, and filler content. The reduction in activation energy of AC conductivity with temperature points toward their semiconducting nature. PMMA/CuO nanocomposites with higher tensile strength, lower bandgap energy, higher conductivity, and thermal properties can be used to make flexible optoelectronic devices.Highlights A series of PMMA/CuO nanocomposites were synthesized and characterized. Enhanced optical property, thermal stability, and glass transition temperature. Possess excellent dielectric constant and AC conductivity. Mechanical strength and impact resistance of PMMA were greatly enhanced. A promising material for flexible optoelectronic and power storage applications.

Enhanced mechanical, electrical, thermal, and optical properties of poly(methyl methacrylate)/copper oxide nanocomposites for flexible optoelectronic devices via in‐situ polymerization technique

Anju,

Ramesan

2024

Control of curing kinetic and strong interaction between resins network and boehmite nanoparticles: Dynamic‐mechanical and curing kinetics study

Rouhi,

Poorabdollah,

Bahrami

2024

In this study, two characteristics of boehmite nanoparticles (BNs) were used to improve the dynamic‐mechanical properties of pure unsaturated polyester resin (Neat UP). (1) Boehmite's ability to target free radical control in the radical curing reaction of UP resin, and (2) adsorption of alkyd chains and creation of attractive interactions with the resin network. X‐ray diffraction (XRD), Fourier‐transform infrared spectroscopy (FT‐IR), and field‐emission scanning electron microscopy (FESEM) analysis were used to identify the synthesis of particles. The results of FESEM analysis showed that the average particle size was 80–100 nm. TGA was used to investigate the thermal properties of the Neat UP and UP resin containing 0.3 wt% BNs (UP 0.3 BNs). The results of the dynamic‐mechanical analysis showed that the elastic modulus of the UP 0.3 BNs composite increased by 42% compared to the Neat UP. To investigate the significant increase observed in the dynamic‐mechanical properties, the curing kinetics were investigated by differential scanning calorimetry (DSC). Investigating the activation energy in terms of the conversion degree showed earlier dominance of the diffusion phenomenon in the UP 0.3 BNs composite. Investigating the diffusion factors provided by Vyazovkin–Sbirrazzouli showed a significant decrease in K and ED in the UP 0.3 BNs composite (−10.5, 19 kJ/mol) compared to the Neat UP resin (−9.5, 40 kJ/mol).Highlights Targeted control of free radicals increases network regularity of the UP/BNs. Impressive improvement of mechanical properties of UP/BNs compared to Neat UP. Increasing diffusion phenomenon dominance of UP/BNs system compared to Neat UP.

Impact resistance of polyurethane elastomer enhanced by organic montmorillonite with interlayer anchored polymer chains

Zhao,

Fu,

et al. 2024

The development of materials with excellent impact resistance is essential for safety protection. Polyurethane elastomer (PUE) is widely used in impact protection; however, it has low dynamic compressive strength and poor energy absorption efficiency under high‐speed impact, limiting its in‐depth application in the protection field. Herein, an organic montmorillonite (MMT) with interlayer anchored polymer chains, named M@NH3+, was synthesized via the dual modification of MMT involving surface grafting and cation intercalation by macromolecular amino silane, which was used to enhance the impact resistance of PUE. Based on the uniform dispersion of M@NH3+ within the PUE matrix, the strong bonding at the polymer‐filler interface and the synergistic action between M@NH3+ lamellae, PUE‐M@NH3+ composite exhibited excellent mechanical properties and energy absorption capacity. Compared with pure PUE, the elastic modulus (+98.3%), static compressive strength (+37.0%), dynamic compressive strength (+35.4%) and impact energy absorption (+50.8%) of PUE‐2wt%M@NH3+ were significantly improved, which shows that it has potential applications in the field of high‐speed impact protection.Highlights Organic MMT with interlayer anchored polymer chains was prepared. The large interlayer spacing of M@NH3+ facilitates its dispersion within the matrix. The interconnected M@NH3+ lamellae can collaboratively disperse impact stress. The impact energy absorption of PUE composite has been remarkably improved.