Mechanically Robust Fluorinated Graphene/Poly(<i>p</i>‑Phenylene Benzobisoxazole) Nanofiber Films with Low Dielectric Constant and Enhanced Thermal Conductivity: Implications for Thermal Management Applications

Low-dielectric materials have found broad applications in microelectronics but are limited by poor mechanical properties and thermal conductivity. In this study, a class of nanocomposite films based on fluorinated graphene (FG) was developed by replacing the traditional polymer matrix with a 3D interconnected poly(p-phenylene benzobisoxazole) (PBO) nanofiber network. The FG nanosheets are uniformly distributed in the porous network of PBO nanofibers (PBONF) and stacked orderly to form a nacre-like layered structure while paving effective thermal conduction paths. Ultimately, the strong interfacial bonding and efficient synergy between FG and PBONF endow the composite films with unparalleled tensile properties (strength and modulus up to 295.4 MPa and 7.79 GPa, respectively) and folding endurance (no drop in tensile properties after 1000 folds), ultralow dielectric constant (as low as 1.71), and excellent thermal conductivity (12.13 W m–1 K–1). In addition, these FG/PBONF composite films also exhibit an ultrahigh thermal stability (5% weight loss temperature higher than 540 °C), which makes them promising for the heat dissipation of high-power electronic devices in extreme environments

Novel Biodegradable and Double Crystalline Multiblock Copolymers Comprising of Poly(butylene succinate) and Poly(ε-caprolactone): Synthesis, Characterization, and Properties

A series of double crystalline multiblock copolymers composed of poly­(butylene succinate) (PBS) and poly­(ε-caprolactone) (PCL) have been successfully synthesized with hexamethylene diisocyanate (HDI) as a chain extender. The copolymers were systematically characterized by ¹H NMR, GPC, TGA, DSC, WAXD, and mechanical testing. The results indicate that the PBS segment is immiscible with the PCL segment in the amorphous region. The copolymers follow a two-stage degradation behavior, and thermal stability increases with increasing PBS content. PBS and PCL in the copolymers crystallize and melt separately. The mechanical properties of the copolymers can be conveniently adjusted from rigid plastics to flexible elastomers by changing the feed composition. The impact strength is substantially improved by the incorporation of the PCL segment