A Novel Phosphorus‐Containing Polymer as a Highly Effective Flame Retardant

Summary: A novel phosphorus‐containing polymeric retardant, WLA‐3, was synthesized from phenylphosphonic dichloride (PPD) and 2‐(6‐oxido‐6H‐dibenz〈c,e〉〈1,2〉oxaphosphorin‐6‐yl) 1, 4‐benzenediol (ODOPB). The flame‐retardant element, phosphorus, was bonded both in the main chains and in the pendant chains of flame‐retardant polymer molecules, and reached a content of 13.8%. The high phosphorus content and rich aryl group structures of WLA‐3 contribute an excellent flame retardancy to poly(ethylene terephthalate) (PET) without a considerable decrease of mechanical properties. WLA‐3 is also very effective in improving flame retardancy of epoxy resin and unsaturated polyester. magnified image