Yichen Tian,Chuyi Wang,Yuanfang Ai,Longcheng Tang,Kun Cao
Phytic acid-based phosphate esters (PAPEGs) were prepared through the reaction between phytic acid (PA) and different proportions of polyethylene glycol 200 (PEG-200). Intumescent flame-retardant coating (IFRC) with PAPEG3, PAPEG6, PAPEG9 and PAPEG12 were obtained via thermal curing of PAPEGs and melamine formaldehyde resin (MFR), respectively. The backside temperature of steel with MFR/PAPEGs coating was much lower than that of MFR/PA coating. MFR/PAPEG6 coating showed the best flame retardancy, and the char thickness reached 48 mm from initial thickness of 0.4 mm, and the expansion ratio was 120 times. Cone calorimeter confirmed that the incorporation of PAPEG6 could minimize the heat release rates and total heat release of materials during combustion. Moreover, the MFR/PAPEGs coating possessed both excellent transparency and water resistance. The transmittance of MFR/PAPEG6 and MFR/PAPEG9 was above 87% at 600 nm, and transmittance of MFR/PAPEG12 even reached 90%. The proposed flame-retardant mechanism was that MFR/PAPEGs produced phosphorus-containing acids to dehydrate and carbonize PEG, leading to the formation of graphitized chars. Meanwhile, the nitrogen-containing intermediates simultaneously released noncombustible gases to expand the char and interrupt the combustion reaction.
The versatile modification of silk fabric using a fully biobased approach is intriguing. In this study, phytic acid and vanillin, which are plant extracts, were utilized to synthesize reactive vanillin phytate ester for modifying silk fabric to achieve durable flame retardancy, antibacterial and anti-UV performance. The multifunctional properties, thermal resistance, smoke and heat suppression capacity, flame-retardant durability and mechanism of modified silk fabrics were investigated. The vanillin phytate ester imparted high antimicrobial and UV resistance to silk fabric, achieving a 97 % inhibition rate against Escherichia coli and reaching an “excellent” level of UV protection. The modified silk fabric also possessed the self-extinguishing capacity, with a limiting oxygen index value as high as 33.5 %. There was also a significant reduction of 71.7 % in peak heat release and 40 % in smoke release compared with those of the original silk. After undergoing 20 washing cycles, the modified silk fabrics also self-extinguished and passed the vertical burning test, and such good washing resistance was achieved by the Schiff base cross-linking of vanillin phytate ester on the silk fabric. An intumescent flame-retardant mechanism was also identified by char residue analyses, which was driven by the synergistic charring action of phosphate groups and aromatic structures.
危险品化学品经营许可证（带存储）