Modified ammonium polyphosphate (MAPP) was prepared as a novel mono-component intumescent flame retardant (IFR) via the ionic exchange between ammonium polyphosphate (APP) and piperazine sulfonate, which is synthesized by self-assembly using 1-(2-aminoethyl) piperazine (AEP) and p-aminobenzene sulfonic acid (ASC) as raw materials. This all-in-one IFR integrating three functional elements (carbon, acid, and gas source) showed more efficient flame retardancy and excellent smoke suppression as well as better mechanical properties than the conventional APP. The incorporation of 22.5 wt.% MAPP into polypropylene (PP) eliminated the melt dripping phenomenon and passed the UL-94 V-0 rating. The results of the cone calorimetry test (CCT) revealed that the release of heat, smoke, and CO is significantly decreased, demonstrating that this novel IFR endows PP with excellent fire safety more effectively. For PP/MAPP composites, a possible IFR mechanism was proposed based on the analysis of the pyrolysis gas and char residues.

The partial oxidation of methane (POM) into value-added C₁ chemicals (e.g., CH₃OH, HCHO, and CO) offers a promising approach for natural gas utilization under mild conditions. However, existing POM systems often rely on complex catalyst designs and the addition of extra oxidants. Here, we developed a catalyst-free POM system by integrating mechanical stirring with a low-frequency ultrasonic field. A high production rate of C₁ chemicals (129.26 µmol h^-1) and methane conversion rate (22%) were achieved under ambient conditions (298 K, P_CH4 = 0.1 bar, P_O2 = 0.1 bar, P_N2 = 0.8 bar). Mechanism studies revealed that the introduction of mechanical stirring amplified the ultrasonic cavitation effect, promoting the in-situ release of reactive oxygen species. Reaction pathway investigation confirmed that hydroxyl radicals facilitated the cleavage of methane C-H bonds and that oxygen participated in the generation of POM products. This strategy provides a sustainable avenue for the value-added conversion of methane.

Modified ammonium polyphosphate (MAPP) as a novel mono-component intumescent flame retardant (IFR) was prepared via the ionic exchange between ammonium polyphosphate (APP) and piperazine sulfonate, which is synthesized by self-assembly using 1-(2-Amioethyl) piperazine (AEP) and p-amino benzene sulfonic acid (ASC) as raw materials. This all-in-one IFR integrating three functional elements (carbon, acid, and gas source) showed more efficient flame retardancy and excellent smoke suppression as well as better mechanical properties than the conventional APP. The incorporation of 22.5 wt.% MAPP into polypropylene (PP) eliminated the melt dripping phenomenon and passed the UL-94 V-0 rating. The results of the cone calorimetry test (CCT) revealed that the release of heat, smoke, and CO is significantly decreased, demonstrating that this novel IFR endows PP with excellent fire safety more effectively. For PP/MAPP composites, a possible IFR mechanism was proposed based on the analysis of the pyrolysis gas and char residues.