Fabrication of Enhanced Mechanical Properties and Intrinsic Flame-Retardant Polyurethane Elastomer Containing 4-(Phenylethynyl) Di(Ethylene Glycol) Phthalate

In this study, the aromatic acetylene compound 4-(phenylethynyl) di(ethylene glycol) phthalate (PEPE) was used as a chain extender, partially replacing 1,4-butanediol. To synthesize an intrinsic flame-retardant thermoplastic polyurethane elastomer (TPU) with an aromatic acetylene structure, PEPE was synthesized by a two-step polymerization. The flame retardancy, thermal stability, and mechanical properties of TPU were studied. The microstructure of TPU char was investigated by scanning electron microscopy to analyze the flame-retardant mechanism. The tensile strength of TPU containing 1.35 wt% PEPE was 39.2 MPa, which was almost twice as much as neat TPU, showed a dramatic decrease in the peak heat release rate and total heat release, and declined by 46.2% and 24.5%, respectively. After the flame-retardant TPU burned, a cross-linked network foaming char structure was formed. The results showed that PEPE improved the mechanical properties of TPU and conferred good stability that promoted the formation of charcoal and reduced heat release during the combustion of TPU.

Übergangsmetallketen-Verbindungen, XII [1] Darstellung und Struktur von η5-C5H5(CO)2 [P(CH3)3]W-C≡C-C3H5 / Compounds of Transition Metal Ketenes, XII [1] Synthesis and Structure of η5-C5H5(CO)2 [P(CH3)3]W-C≡C-C3H5

Dicarbonyl(η5-cyclopentadienyl)(η1 -cyclopropylketenyl)(trimethylphosphane)tungsten reacts with carbon monoxide under reduction of the ketene moiety forming a (σ-bonded acetylene compound. Reaction conditions, spectroscopic data and the X-ray structure of the new compound are reported.