乙醇/水无卤发泡及木质素磷酸酯基阻燃硬质聚氨酯泡沫的制备及性能研究

Study on Preparation and Performance of Ethanol/Water Halogen-Free Foaming and Lignin Phosphate Flame Retardant Rigid Polyurethane Foam

首先用二苯氧基磷酰氯与碱木质素反应合成木质素磷酸酯反应型阻燃剂,再以乙醇、水协同作无卤发泡剂,木质素磷酸酯、可膨胀石墨协同作无卤阻燃剂,制备了无卤发泡及阻燃硬质聚氨酯泡沫。结果表明,使用乙醇作发泡剂可显著降低物料黏度,提高物料流动性,使发泡反应更完全。傅里叶变换红外光谱(FTIR)及核磁共振氢谱(1 H NMR)分析表明已成功制备木质素磷酸酯反应型阻燃剂,正交试验及统计产品与服务解决方案(SPSS)数据分析确定具有26.6%最高聚氨酯泡沫极限氧指数(LOI)的木质素改性工艺参数为:二苯氧基磷酰氯7 g、反应温度60℃、反应时间5 h。热重(TG/DTG)分析结果表明木质素苯环的环状结构,磷酸液膜、蠕虫状膨胀石墨炭层及聚氨酯降解后残渣炭层形成的致密联合体提高了炭层的热稳定性,添加木质素磷酸酯/可膨胀石墨(EG)前后无卤发泡硬质聚氨酯泡沫在800℃的残炭量分别为19.3%、27.4%。聚氨酯泡沫表观密度随着木质素磷酸酯添加量的增加而增加,压缩强度先上升后下降,压缩强度最高时可达485.2 kPa。

Firstly,diphenoxyphosphorus oxychloride was reacted with alkali lignin to synthesize lignophosphate reactive flame retardant,and then ethanol and water were used as halogen-free foaming agent,and lignophosphate and expandable graphite were used as halogen-free foaming agent.The halogen-free foam and flame retardant rigid polyurethane foam was prepared.The results show that the use of ethanol as a foaming agent can significantly reduce the viscosity of the material,improve the fluidity of the material,and make the foaming reaction more complete.Fourier transform infrared spectroscopy(FTIR)and hydrogen nuclear magnetic resonance spectroscopy(1 H NMR)analysis show that the lignophosphate reactive flame retardant is successfully prepared.Orthogonal test and statistical product service solutions(SPSS)data analysis confirm when diphenoxyphosphoryl chloride is 7 g,reaction temperature is 60℃,reaction time is 5 h,it has the highest limited oxygen index(LOI)of 26.6%for polyurethane foam.Thermogravimetric(TG/DTG)analysis results show that the ring structure of lignin benzene ring,the dense combination of phosphoric acid liquid film,worm-like expanded graphite carbon layer and residual carbon layer after polyurethane degradation could improve the thermal stability of the carbon layer.The carbon residues of the halogen-free foamed rigid polyurethane foam at 800℃are 19.3%and 27.4%,respectively,before and after adding lignin phosphate/expandable graphite(EG).The apparent density of polyurethane foam increases with the addition of lignin phosphate,and the compressive strength first increases and then decreases,and the highest compressive strength can reach 485.2 kPa.