Preparation of novel dendritic flame‐retardant polymer and its application in EPDM composites

Flame‐retardant polymer, dendritic tetramethylolphosphonium chloride (FR‐DTHPC), was prepared by condensation polymerization between THPC, the monomer we prepared, and boric acid. It was then characterized by Fourier transform infrared spectroscopy, intrinsic viscosity, and matrix assisted laser desorption ionization time of flight mass spectrometer. This FR‐DTHPC was used in the preparation of flame‐retardant ethylene propylene diene monomer (EPDM) composites. Different types of EPDM/FR‐DTHPC composites were prepared with different amounts of FR‐DTHPC. Then, the cure characteristic, tensile properties, flame‐retardance, and thermal stability were researched and compared. Results showed that the addition of this novel additive can improve some mechanical and flame‐retardant properties of EPDM composites. Mechanisms of reinforcing and flame‐retardance were proposed. The dendritic polymer may reduce the amount and size of voids in EPDM composites, and thus may increase their tensile properties. Meanwhile, the degradation products from nitrogen, phosphorus, and boric acid in FR‐DTHPC can increase the amount of carbonaceous layers, and thus can inhibit the pyrolysis degree of EPDM composites during burning and improve their flame‐retardant performance. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40855.