Fabrication of Green and Scalable N/P/S/Mn Containing Biobased Layered Double Hydroxide as a Novel Flame Retardant and Efficient Char Forming Agent for Polypropylene

Abstract

To date, designing efficient bio-based flame retardants for polypropylene (PP) and exploring a green and scalable strategy have remained a hot topic of research. Here, we present a green and convenient preparation of a bio-based flame retardant (LDH-LS@CS@PAMn) for layer-by-layer assembly by utilizing water as an assembly medium. By electrostatic interactions, LDH-LS@CS@PAMn was prepared by the sequential assembly of sodium lignosulfonate-modified layered double hydroxide (LDH-LS) with positively charged chitosan (CS) followed by negatively charged sodium phytate (PAMn). With increasing LDH-LS@CS@PAMn loading in PP composites, the corresponding total heat release rate (THR) and peak heat release rate (PHRR) values were reduced remarkably. With loading 20 wt % LDH-LS@CS@PAMn, the THR and PHRR of PP/LDH-LS@ CS@PAMn decreased by 37.6 and 59.1%, respectively, while the limiting oxygen index significantly improved to 31.6% and the V-0 rating was successfully passed by the UL-94. Especially for PP/LDH-LS@CS@PAMn composites, the total smoke production (TSP) was reduced by 47.4%. More importantly, the residual PP/LDH-LS@CS@PAMn char changed from gray to brown-black compared to PP/LDH, indicating a stronger residual char formation. The outstanding fire safety, smoke suppression, and char formation capabilities of PP composites were ascribed to the synergistic LDH-LS@CS@PAMn hybrid's action. This work provided a feasible and reasonable modification idea to improve smoke suppression and flame retardancy for LDH.

Boron-Based Polyphosphazene-Functionalized Mxene Nanosheets for Polypropylene Composites with Improved Mechanical Properties and Flame Retardancy Applications

“…However, the smoke release from Ti 3 C 2 T x @PPD is slightly enhanced, because DA was used as the graft monomer to keep phosphorus in a lower oxidation state in the polyphosphazene structure, resulting in increased release of phosphorus-containing volatiles. , This shows that the PPD structure has certain gas-phase flame-retardant properties. As shown in Figure e, the Ti 3 C 2 T x @PPD/PAPP system has obvious advantages in key flame retardant performance parameters compared with those reported in the literature. − It is worth mentioning that 24 wt % (2% Ti 3 C 2 T x @PPD/22% PAPP) addition is required to pass the V-0 rating; it is not outstanding compared to gas-phase flame retardants. However, Ti 3 C 2 T x @PPD has an important role in inhibiting thermal hazards during combustion and controlling the generation of smoke and toxic gases.…”

Structure of Metal–Organic Frameworks Eco-Modulated by Acid–Base Balance toward Biobased Flame Retardant in Polyurea Composites

“…Furthermore, the HRR–time curve of the PUA composite blended with ZIF@Arg–Co–PA exhibits a narrower peak span, which is attributed to the inhibition of combustion heat transfer by the fillers with catalytic char-forming properties. However, PUA/Arg–Co–PA presents a HRR peak with the largest span, which may be due to the weak barrier of the reformed char layer after the fracture of the preformed char layer . The flame retardancy index (FRI), a dimensionless general index, is applied to evaluate the flame retardancy of composites based on cone calorimetry data .…”

Pathways for Sustainable Adoption of Chitosan-Based Beads in Water Treatment

“…5 Driven by the urgent need to safeguard our water resources, water treatment technologies are evolving unprecedentedly with focus on both novel and sustainable solutions. [6][7][8][9][10][11] A variety of methodologies for alternatives to petroleum-based resins have been proposed and implemented; however, finding the right balance between treatment efficacy and sustainability is the focus of ongoing studies. 12 Among the promising solutions are biopolymeric beads, which offer a potentially more sustainable alternative to conventional petroleum-based resins.…”