Fabrication And Application Of Biomass Polyphenol Flame Retardant Multifunctional Coatings

Polymeric materials have been applied in construction,decoration,home textile and other fields due to their lightweight,flexible molecular structure,easy processing,and so on.They have become an important cornerstone of modern economic construction and scientific and technological development.However,the massive use of polymeric materials has brought huge hidden dangers to the safety of people’s lives and property.49%of residential fires are caused by upholstered furniture,so it is necessary to treat them with the flame retardancy.This paper takes cotton fabrics（Cotton）and flexible polyurethane foam（FPUF）as examples to improve their fire safety.Four kinds of tea polyphenol-based flame retardants were designed and synthesized,which were coated to the surface of cotton fabrics and FPUF by dip-coating,and their flame retardancy,antibacterial activity,anti-UV property,mechanical property and other physical and mechanical properties were investigated in detail.Firstly,tea polyphenols（TP）,phenyl phosphonic acid（PPOA）and iron（Ⅲ）sulfate hydrate（Fe₂（SO₄）₃）were used as raw materials to prepare tea polyphenols-iron-phenyl phosphonic acid complex（TP-Fe-PPOA）.It was coated on the cotton fabric surface by dip-coating.The results showed that TP-Fe-PPOA can evenly adhere to the surface of cotton fabrics.Cotton/TP-Fe-PPOA can self-extinguish,its damage length was only 6.7cm in vertical flame test（VFT）,and the limiting oxygen index（LOI）increased from17.6%to 24.7%of cotton fabrics.Meanwhile,the peak heat release rate（PHRR）of Cotton/TP-Fe-PPOA was 11.8%lower than that of cotton fabrics.In addition,anti-bacterial and anti-UV properties were also greatly improved.The antibacterial activities of Cotton/TP-Fe-PPOA against S.aureus and E.coli were 99.99%and the UV protection factor（UPF）of Cotton/TP-FE-PPOA increased from 7.5 to 37.9,close to the requirement of sunscreen products.It has prepared the flame retardant,anti-bacterial and anti-UV cotton fabrics preliminarily.Secondly,Fe₂（SO₄）₃was replaced by melamine（MA）to prepare a tea polyphenol-melamine-phenylphosphonic acid flame retardant coating（TP-MA-PPOA）,which can further slow the spread of the flame.The damage length of Cotton/TP-Fe-PPOA was only7.4 cm in VFT,and the LOI increased to 28.7%.Meanwhile,Cotton/TP-MA-PPOA had an 88.5%lower PHRR and a 92.9%lower fire growth rate compared with those of cotton fabrics.And the risk of fire was sharply reduced.In addition,the UPF value of Cotton/TP-MA-PPOA was 35.2,and the antibacterial activities against S.aureus and E.coli were 99.99%.Therefore,TP-MA-PPOA coating gave the cotton fabrics flame retardancy,antibacterial and anti-UV properties.Due to the good performance of tea polyphenol-based flame retardant on cotton fabrics,its application was extended to FPUF.FPUF/TP-Fe-3PA can pass the UL-94 V-0rating,and the LOI can reach 26.2%.The PHRR and total smoke production（TSP）of FPUF/TP-Fe-3PA were reduced by 67.7%and 66.7%,respectively,compared with those of FPUF.And the release of toxic gases such as isocyanate was also greatly reduced.The existence of the flame retardant coating also endowed FPUF with well antibacterial properties,with inhibition rate of 99.99%against S.aureus and E.coli.In addition,the presence of the flame retardant coating had little impact on the resilience of FPUF,but the tensile property had been reduced.A flame retardant coating was constructed on the FPUF surface by dip-coating based on TP,Ni Cl₂and laponite（LAP）.FPUF/1LAP/4TP-Ni showed self-extinguished behaviors at once and passed the UL-94 V-0 rating,and the LOI was 22.6%.Additionally,the values of PHRR and TSP of FPUF/1LAP/4TP-Ni were reduced by 71.6%and 61.3%,compared with those of FPUF.The content of gaseous toxic substances was also decreased,such as CO and NCO-containing compounds.In addition,the flame retardant coating increased the tensile strength of FPUF by 21%.After 20 cycles of compression-release tests under 50%compression strain,the height loss was close to that of FPUF,only 14.2%.The antibacterial activities of FPUF/1LAP/4TP-Ni against S.aureus and E.coli were 99.99%.Thus,these inorganic-organic hybrid coatings basically realized the preparation of flame retardant and antibacterial FPUF with good mechanical property.Four kinds of tea polyphenol-based flame retardants were designed and coated to the surface of cotton fabrics and FPUF,which significantly improved their fire safety and anti-bacterial properties.It has expanded the application of biomass polyphenols in flame retardant field,which provided an effective way for multifunctional flame retardant cotton fabric and FPUF.