Ya-Nan Wu,Hai-Bo Zhao,Ming-Jun Chen,Lei He,Dan-Xuan Fang,Shuai-Qi Guo,Fu-Rong Zeng,Yu-Zhong Wang
Semi-rigid polyurethane foams (SPUF) with high deformation resistance and strength are indispensable for cushioning applications. However, for high fire risk and cascaded pollutant effects, overused multifarious additives and foam wastes exacerbate global environmental concerns. One option to address this issue is to develop eco-friendly multifunctional flame retardants that participate in the material lifecycles of preparation, safe service, waste management, and sustainable recycling. Herein, a novel self-adaptive catalytic strategy is reported that exploits the temperature and agent structure-responsive catalytic ability of eco-friendly sodium propionate (SP), reconciling the often-conflicting properties of fabrication and recycling while effectively mitigating combustion risks and additive pollution. The adaptive catalytic function of SP impressively involves all aspects of foam life cycles: 1) catalyzing foaming without complex/hazardous catalysts; 2) providing superior flame-retardant efficiency with a high limiting oxygen index of 25.5% without relying on traditional flame retardants; 3) promoting in situ network fragmentation and reorganization into strong adhesives (5.8 MPa); and 4) further recycling of the newly formed adhesives in a self-driven sustainable manner. A novel green strategy is presented that addresses fire hazards, plastic pollution, and the unsustainability of recycling, minimizing the ecological risks of foam, which will positively impact future sustainable material design involving diverse additives.
Ge Ge,Jianan Liu,Yunfei Liao,Deli Zeng,Hongyan Mou,Huiming Fan
To address the challenges of difficulty and low penetration speed of aqueous deacidification agents in paper, we aimed to enhance the wetting performance of these agents by incorporating a surfactant. We selected four surfactants for our study: anionic sodium dodecyl benzene sulfonate (SDBS), cationic cetyltrimethylammonium bromide (CTAB), nonionic polysorbate-80 (TW80), and polyether-modified trisiloxane (TRSE). The wetting properties of these surfactants on sodium propionate aqueous deacidification agent, the alkali stability of the solution, and the effects of moist heat aging on paper durability were explored. The results demonstrated that TRSE exhibited superior performance compared to the other three surfactants, effectively reducing the surface tension of sodium propionate solution to 21.02 mN/m. In alkaline conditions with a pH range of 8.00–10.00, the surface tension of SDBS, CTAB, and TW80 solutions remained stable for 30 days. Similarly, under weakly alkaline conditions with a pH value below 9, the surface tension of TRSE solutions exhibited stability. It should be noted that SDBS accelerated the decline of paper tensile index and whiteness during the heat and humidity aging process; at the same time, CTAB, TW80, and TRSE had no noticeable adverse effects on paper aging resistance.