Cross‐linked poly(benzoxazole‐ co ‐siloxane) networks with high thermal stability and low dielectric constant based on a new ortho ‐amide functional benzoxazine

Integrating Benzoxazine-PDMS 3D Networks with Carbon Nanotubes for flexible Pressure Sensors

Shapeable and flexible pressure sensors with superior mechanical and electrical properties are of major interest as they can be employed in a wide range of applications. In this regard, elastomer-based composites incorporating carbon nanomaterials in the insulating matrix embody an appealing solution for designing flexible pressure sensors with specific properties. In this study, PDMS chains of different molecular weight were successfully functionalized with benzoxazine moieties in order to thermally cure them without adding a second component, nor a catalyst or an initiator. These precursors were then blended with 1 weight percent of multi-walled carbon nanotubes (CNTs) using an ultrasound probe, which induced a transition from a liquid-like to a gel-like behavior as CNTs generate an interconnected network within the matrix. After curing, the resulting nanocomposites exhibit mechanical and electrical properties making them highly promising materials for pressure-sensing applications.

Application of Vitreoscilla Hemoglobin as a Green and Efficient Biocatalyst for the Synthesis of Benzoxazoles in Water

We report an efficient and eco-friendly method for the Vitreoscilla hemoglobin (VHb)-catalyzed synthesis of benzoxazoles in water at room temperature. tert-Butyl hydroperoxide and 2,2,6,6-tetramethyl-1-piperidinyloxy were used as oxidant and radical scavenger, respectively. A total of 27 functionally diverse benzoxazoles were prepared in moderate to high yields (62 %-94 %) by the annulation reaction of phenols with amines in the presence of VHb in 1 h. Thus, this method is highly viable for practical applications. This work broadens the application of hemoglobin to organic synthesis.

Recent Progress of Low Dielectric and High-Performance Polybenzoxazine-Based Composites

With the rapid advancement of intelligent electronics, big data platforms, and other cutting-edge technologies, traditional low dielectric polymer matrix composites are no longer sufficient to satisfy the application requirements of high-end electronic information materials, particularly in the realm of high integration and high-frequency, high-speed electronic communication device manufacturing. Consequently, resin-based composites with exceptional low dielectric properties have garnered unprecedented attention. In recent years, benzoxazine-based composites have piqued the interest of scholars in the fields of high-temperature-resistant, low dielectric electronic materials due to their remarkable attributes such as high strength, high modulus, high heat resistance, low curing shrinkage, low thermal expansion coefficient, and excellent flame retardancy. This article focuses on the design and development of modification of polybenzoxazine based on low dielectric polybenzoxazine modification methods. Studies on manufacturing polybenzoxazine co-polymers and benzoxazine-based nanocomposites have also been reviewed.

Two high toughness and flame retardant DOPO-containing polybenzoxazines based on polyether-urea

In this current work, two new-style DOPO-containing benzoxazines based on polyether-urea were successfully synthesized by a modified version via three-step procedures, and the corresponding polybenzoxazines with high toughness and flame retardancy were obtained by thermal activated polymerization. The single and double DOPO-containing benzoxazines were named as BzD1 and BzD2, respectively. The corresponding polymers followed were named as PBzD1 and PBzD2, respectively. The curing behaviors of the two new benzoxazines were investigated by differential scanning calorimetry. The thermal and mechanical properties of the materials were evaluated by TGA and dynamic mechanical analysis. The flame retardant properties were elucidated via limiting oxygen index (LOI). The toughness properties were expressed by bending tests. The results showed that the Yc for PBzD1 and PBzD2 were approximately 22.2% and 24%, respectively, distinctively higher than the value 2.57% of pristine polybenzoxazine PBz1, at 800 °C in N2 atmosphere. The Tgs of PBzD1 and PBzD2 distinctly increased by 42.8 °C and 20 °C, respectively, in comparison to −35 °C for pristine PBz1. The LOI values of PBzD1 and PBzD2 were 28.5 and 31, respectively. The length and weight-loss of PBzD1 and PBzD2 samples were significantly less than that of PBz1 when they were burned in the air environmental condition. The burning behavior demonstrated that the flame retardant properties was obviously improved as DOPO was introduced. All of the three specimens of PBz1, PBzD1 and PBzD2 presented excellent flexible property.

Vitrimers trigger covalent bonded bio-silica fused composite materials for recycling, reshaping, and self-healing applications

Bio-based benzoxazines used eugenol and incorporated bio-silica (BS) and trimethylolpropane-tris(3-mercaptopropionate) (SH) for self-healing, recycling, and reshaping applications.

Synthesis of a triptycene-containing dioxazine benzoxazine monomer and a main-chain triptycene-polydimethysiloxane-benzoxazine copolymer with excellent comprehensive properties

A novel triptycene-containing dioxazine benzoxazine monomer and a main-chain benzoxazine copolymer have been synthesized and their corresponding thermosets exhibit excellent thermal stability, low flammability and low dielectric constants.

Development of a fully bio-based hyperbranched benzoxazine

A fully bio-based hyperbranched benzoxazine derived from renewable raw materials exhibits excellent thermal properties.