Description

2,2'-Diphenyl-5,5'-Spirobi[1,3,2-Dioxaphosphorinane]2,2'-Dioxide is a high-purity, organophosphorus compound with the CAS number 59609-12-0. This specialized chemical serves as a highly effective flame retardant and a reactive intermediate in advanced polymer synthesis. It is primarily required by manufacturers in the polymer, plastics, and specialty chemical industries seeking to enhance the fire safety and thermal stability of their materials. Its unique spirocyclic structure provides excellent compatibility and performance in demanding formulations.

Application

• As a reactive flame retardant in epoxy resins, polyurethanes, and unsaturated polyesters.
• As a key synergistic additive in halogen-free flame-retardant systems for engineering plastics.
• As a building block for synthesizing novel phosphorus-containing polymers and oligomers.
• In the production of high-performance composites for the electronics and automotive sectors.
• As a thermal stabilizer and processing aid in specialty plastic formulations.
• For research and development of new flame-retardant coatings and adhesives.

Basic Information

Product Name	2,2'-Diphenyl-5,5'-Spirobi[1,3,2-Dioxaphosphorinane]2,2'-Dioxide
CAS No.	59609-12-0
Molecular Formula	C21H20O6P2
Molecular Weight	430.33 g/mol
Synonyms	Spirocyclic Phenyl Phosphonate; SPDOP; 2,2'-Diphenyl-5,5'-spirobi(dioxaphosphorinane) 2,2'-dioxide; Spiro(diphenyl phosphonate); Spirobis(1,3,2-dioxaphosphorinane) derivative; Phenyl spiro phosphonate; Flame Retardant SPDOP; Bis(5-phenyl-1,3,2-dioxaphosphorinanyl) oxide
EINECS	Contact for details

Quality Control

Our 2,2'-Diphenyl-5,5'-Spirobi[1,3,2-Dioxaphosphorinane]2,2'-Dioxide is manufactured under strict quality management systems. Every batch undergoes rigorous analytical testing, including HPLC and NMR, to ensure high purity and consistent performance. Certificates of Analysis (COA) detailing all specifications are provided with each shipment to guarantee compliance with your technical requirements.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from strong acids, strong bases, and oxidizing agents. The container must be kept tightly sealed to minimize exposure to atmospheric moisture.

Specification

Item	Specification
Appearance	White to off-white crystalline powder
Identification (IR)	Conforms to structure
Assay (HPLC)	≥ 98.0%
Melting Point	285 - 295 °C
Loss on Drying	≤ 0.5%
Residue on Ignition	≤ 0.1%

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.