【摘要】 利用生物质单宁取代部分苯酚,定量尿素作为甲醛捕捉剂,制备了单宁改性可发泡酚醛树脂,然后以硫酸与对甲苯磺酸混合酸作为固化剂,正戊烷为发泡剂,制备了单宁改性酚醛泡沫。利用傅里叶变换红外光谱和核磁共振氢谱对树脂结构进行了表征,依据GB/T 30694–2014检测了不同单宁用量对酚醛泡沫甲醛释放量的影响,使用电子万能试验机和极限氧指数(LOI)仪检测了不同单宁用量对酚醛泡沫力学性能和阻燃性能的影响。结果表明,改性酚醛泡沫pH为6;当加入的单宁用量为苯酚质量的3%时,改性酚醛泡沫甲醛释放量最低为1.1875 mg/L,达到了人造板E1标准,泡沫压缩强度为0.2166 MPa,冲击强度为2.81 kJ/m~2,粉化率低至2.01%,LOI达到37%,其综合性能最好。相对于纯酚醛泡沫,单宁改性酚醛泡沫的力学性能有所提升,脆性明显改善,阻燃性能显著提高。更多还原

【Abstract】 Biomass tannin was used to replace part of phenol,urea was used as formaldehyde trapping agent,foamable phenolic resins modified by tannin were prepared.Then the mixed acid of sulfuric acid and p-toluenesulfonic acid was used as curing agent and n-pentane was used as foaming agent,phenolic foams modified by tannin were prepared.The structure of the resin was characterized by FTIR and ~1H–NMR,the effects of tannin content on the formaldehyde emission of phenolic foam was detected by GB/T 30694–2014,the effects of tannin content on the mechanical properties and flame retardancy of phenolic foam were tested using an electronic universal testing machine and a limiting oxygen index (LOI) meter.The results show that the pH of the modified phenolic foam is about 6,when the content of tannin added is 3% of the mass of phenol,the minimum formaldehyde emission of phenolic foam is 1.1875 mg/L,which meets the E1 standard of wood-based panels,and the compression strength is 0.2166 MPa,the impact strength is 2.81 kJ/m~2,the pulverization rate is as low as 2.01%,and the LOI is 37%,its comprehensive performance is the best.Compared with pure phenolic foam,the mechanical properties of tannin-modified phenolic foam are improved,and the brittleness is significantly improved and the flame retardancy is improved obviously.更多还原