镁铝层状双氢氧化物改性聚碳酸亚丙酯复合材料的制备及性能研究OA

To enhance the flame retardancy of biodegradable poly(propylene carbonate)(PPC)and suppress its smoke emission during combustion,magnesium-aluminum layered double hydroxides(MgAl-LDHs)were employed as flame retardants,and PPC/MgAl-LDHs composites were prepared via melt blending.The effects of MgAl-LDHs content on the mechanical properties,flame retardancy,smoke suppression performance,thermal stability,and microstructure of the composites were systematically investigated.The results showed that at a MgAl-LDHs mass fraction of 5%,the composites exhibited optimal mechanical properties,with a tensile strength of 31.5 MPa.At MgAl-LDHs mass fractions of 7%～10%,the composites achieved a UL-94 V-0 flammability rating,with significantly improved limiting oxygen index(LOI),and marked reductions in peak heat release rate(PHRR),total heat release(THR),and smoke density level.The initial decomposition temperature and char residue of the composites increased notably with increasing MgAl-LDHs content.The flame-retardant and smoke-suppression mechanisms are attributed to the synergistic effects of the gaseous dilution effect from CO2 and H2O released upon thermal decomposition of MgAl-LDHs,the physical barrier formed by metal oxides,and the promotion of a dense char layer.The study results provide an important reference for developing environmentally friendly,high-efficiency flame-retardant PPC composites with desirable mechanical properties.