Red phosphorus paste

Catalog	ACMA00023457
Description	Surface-coated red phosphorus flame retardant, light red to dark red paste, is an efficient red phosphorus flame retardant. We use proprietary technology to modify red phosphorus, into red phosphorus paste.
Appearance	Light red to dark red fluid
Application	This product can be mainly applied to coatings, textiles, and the like.
Storage	Store in a cool and dry area at room temperature.
Content	P Content 20/30/40/50%
Packaging	Packed in 1250 kg per IBC bucket
Particle Size	max.150 µm, D97
pH	6 to 8(10g/L)
Kinematic Viscosity	Negotiation

Case Study

Silica-Coated Red Phosphorus for Flame Retardant Treatment of Textiles

Gibertini, Eugenio, et al. Surfaces and Interfaces, 2021, 25, 101252.

Red phosphorus (RP) is an inexpensive flame retardant solution with excellent performance, but it has processing limitations: it is prone to reduction reactions to release highly toxic gases, and it is highly flammable and reactive in the form of micronized particles. Therefore, it is necessary to develop encapsulation solutions for RP. In this work, red phosphorus is inorganically encapsulated by obtaining a phosphorus-doped SiO2 shell through a two-step sol-gel route. According to the BS-5852 standard, only fabrics treated with SiO2@RP can successfully self-extinguish in the flammability test, achieving the non-flammability classification required for practical applications.
Red phosphorus encapsulation
· The typical process involved adding RP to 100 ml of NH4OH solution with a 1M concentration at 10 g/L. The red dispersion underwent sonication for two hours using a low-power ultrasonic bath before magnetic stirring was applied.
· A solution of acidic TEOS was made by first combining 10 ml of TEOS with 15.5 ml of distilled water while stirring vigorously using a magnetic stirrer and then slowly adding 1.7 ml of 0.5M H3PO4 solution drop by drop. The final molar ratio TEOS:H3PO4:H2O is 1:0.18:21.1 and pH ~2.
· The homogenized TEOS solution was introduced slowly into the alkaline RP dispersion while stirring vigorously after reaching completion 3 hours later. The dispersion underwent heating at 80◦C after 12h of continuous stirring until gel formation and solvent evaporation were achieved. Following the cooling process to room temperature the coarse aggregates were gently ground using a mortar. The reddish powder of final SiO2@RP underwent drying in a vacuum oven at 100◦C over a period of 1 hour.

Comparison of Flame Retardancy of Coated Red Phosphorus or Naked Red Phosphorus on Rigid Polyurethane Foam

Cao, Zhi-Jie, et al. Polymer Degradation and Stability, 2017, 136, 103-111.

Polyurethane foam (PUF) was prepared by foaming naked red phosphorus (RP) and melamine formaldehyde resin (MFcP) coated RP with isocyanate, and the combustion behaviors of two RPUF/RP and RPUF/MFcP composites were compared.
Evaluation method
This work characterized the physical properties such as densities, compressive strengths, blind hole percentages and thermal conductivities and connected them to both the viscosity of the foaming system and the resulting cell structures.
Evaluation results
· The compatibility between MF and PUF in PUF/MFcP produced better physical properties than those found in PUF/RP. PUF/RP cells developed uneven sizes while their cell struts thickened. PUF/MFcP cells displayed greater uniformity in size alongside enhanced spherical shapes.
· The PUF/MFcP100 sample with 100 pphp of phosphorous demonstrated equivalent vertical burning rates and LOI values to PUF/RP100. Test results from cone calorimetry (CC) demonstrated that PUF/MFcP100 displayed strong flame retardancy alongside significantly reduced smoke and toxic gas emissions. The phosphorus content analysis demonstrated that MFcP operated primarily within the condensed phase whereas RP functioned chiefly within the gaseous phase. The wrap effect of graphitic carbon nitride produced from melamine could explain the observed phenomenon.

If the product of interest is not available in our catalog, please contact us to see if there is any relevant stock or other purchase channels.