Fabrication of nitrogen-doped graphene decorated with organophosphor and lanthanum towards high-performance polymer nanocomposites

Despite substantial advances, it remains imperative but challenging to develop high-performance polymer/graphene nanocomposites combining with excellent mechanical, thermal, and fire-retardant properties. In this work, a novel kind of graphene-based multifunctional nanofiller (La@PN-RGO) was fabricated via the nitrogen doping and the decoration with organophosphorus and lanthanum based on graphene oxide, which is then incorporated into acrylonitrile−butadiene−styrene (ABS) resin via melt blending to obtain resultant ABS nanocomposites. As expected, the La@PN-RGO nanosheets were well dispersed in ABS composites. Attractively, with only 1.0 wt % of La@PN-RGO incorporated into ABS matrix, the peak heat release rate (PHRR) and total smoke production (TSP) were significantly reduced by 38% and 36%, which is much superior to its counterparts at the same nanofillers loading level. The notably enhanced fire safety was primarily attributed to the rare earth catalysis accompanied by the lamellae blocking effect and intumescent flame retardancy of La@PN-RGO. Additionally, ABS/La@PN-RGO composite exhibited a 16% enhancement in tensile strength without at the expense of extensibility. This effective and promising method may open a new pathway to obtain high-performance polymer/graphene nanocomposites

An Additive-Free, Base-Catalyzed Protodesilylation of Organosilanes

We report an additive-free, base-catalyzed C–, N–, O–, and S–Si bond cleavage of various organosilanes in mild conditions. The novel catalyst system exhibits high efficiency and good functional group compatibility, providing the corresponding products in good to excellent yields with low catalyst loadings. Overall, this transition-metal-free process may offer a convenient and general alternative to current employing excess bases, strong acids, or metal-catalyzed systems for the protodesilylation of organosilanes

Fabrication of multifunctional graphene decorated with bromine and nano-Sb2O3 towards high-performance polymer nanocomposites

Despite great advances, it remains highly attractive but challenging to create high-performance polymeric materials combining excellent flame-retardancy and outstanding thermal, mechanical and electrical properties. We herein demonstrate a novel strategy for fabricating a multifunctional nano-additive (Br–Sb2O3@RGO) based on graphene decorated with bromine and nano-Sb2O3. Cone calorimetric tests show that incorporating 10 wt% Br–Sb2O3@RGO into thermoplastic polyurethane (TPU) strikingly prolongs the time to ignition and decreases the peak heat release rate by 72%. Besides, tensile strength and Young's modulus are enhanced by 37% and 820%, respectively. Meanwhile, the electric conductibility is increased by eleven orders of magnitude relative to the TPU matrix. This work provides a promising strategy for addressing the critical bottleneck with the existing flame retardants that only enhance flame retardancy at the expense of mechanical properties of polymeric materials. As-prepared high-performance TPU composites are expected to find many applications, especially in aerospace, tissue engineering, and cables and wires

Functionalizing graphene decorated with phosphorus-nitrogen containing dendrimer for high-performance polymer nanocomposites

In this paper, we demonstrate a novel strategy for fabricating advanced polymer composites based on functionalized graphene oxide decorated with phosphorus-nitrogen-containing dendrimers (PND-GO). Both X-ray diffraction and transmission electron microscopy results show that reduced PND-GO uniformly disperses within polymer matrix and is exfoliated in polyurethane (PU) via in situ polymerization. Cone calorimetry results show that incorporating 2 wt% reduced PND-GO into PU decreases the peak heat release rate by 53% and prolongs the time to ignition by 28 s as compared with the PU bulk. Besides, the tensile strength and Young's modulus are remarkably enhanced by about 2 times and 5 times, respectively

Fabrication of Nitrogen-Doped Graphene Decorated with Organophosphor and Lanthanum toward High-Performance ABS Nanocomposites

Despite substantial advances, it remains imperative but challenging to develop high-performance polymer/graphene nanocomposites combining with excellent mechanical, thermal, and fire-retardant properties. In this work, a novel kind of graphene-based multifunctional nanofiller (La@PN-RGO) was fabricated via the nitrogen doping and the decoration with organophosphorus and lanthanum based on graphene oxide, which is then incorporated into acrylonitrile–butadiene–styrene (ABS) resin via melt blending to obtain resultant ABS nanocomposites. As expected, the La@PN-RGO nanosheets were well dispersed in ABS composites. Attractively, with only 1.0 wt % of La@PN-RGO incorporated into ABS matrix, the peak heat release rate (PHRR) and total smoke production (TSP) were significantly reduced by 38% and 36%, which is much superior to its counterparts at the same nanofillers loading level. The notably enhanced fire safety was primarily attributed to the rare earth catalysis accompanied by the lamellae blocking effect and intumescent flame retardancy of La@PN-RGO. Additionally, ABS/La@PN-RGO composite exhibited a 16% enhancement in tensile strength without at the expense of extensibility. This effective and promising method may open a new pathway to obtain high-performance polymer/graphene nanocomposites