密胺甲醛树脂包覆改性聚磷酸铵

Modification of Ammonium Polyphosphate with Melamine-Formaldehyde Resin

将聚磷酸铵(APP)热活化后与三聚氰胺(MEL)进行反应得到接枝MEL的APP(MAPP),进一步用甲醛交联制得密胺-甲醛树脂包覆改性的APP(MFAPP)。扫描电镜、红外光谱及热重分析结果表明,改性后APP的表面被成功地包覆上了密胺-甲醛树脂,改性APP的起始分解温度从190℃升高到了245℃;研究MEL用量对MFAPP水溶性以及阻燃性能的影响表明,改性后APP的水溶性大幅下降,阻燃性能得到提高。当MEL的质量为APP的8%时,MFAPP的溶解度达到最低,此时70PP/30MFAPP的极限氧指数(LOI)为28%,70PP/20MFAPP/10PER的LOI值达到了35.0%;进一步研究改性对APP与聚丙烯(PP)相容性的影响,结果表明,PP/MFAPP拉伸性能优于PP/APP。

Melamine-formaldehyde resin coated ammonium polyphosphate( MFAPP) was prepared by reacting thermal activated ammonium polyphosphate( APP) with melamine to obtain melamine-grafted ammonium polyphosphate( MAPP) and further crosslinking MAPP with formaldehyde. The results of SEM,FT-IR prove the formation of melamine-formaldehyde resin on the surface of APP,and the thermal gravimetric analysis( TGA) result reveals a rise of the initial decomposition temperature of APP after modification from 190 ℃ to 245 ℃. The influence of the MEL dosage on the water solubility and flame retarding ability of MFAPP was investigated. The results show a drastic drop in the water solubility and an enhancement in the flame retarding ability of APP after modification. When the dosage of MEL is 8%of APP,the water solubility of MFAPP reaches the lowest and the limiting oxygen index( LOI) of 70 PP/30 MFAPP and70PP/20 MFAPP/10 PER composites reaches 28% and 35. 0%,respectively. The influence of modification on the compatibility between PP and APP was also studied,and it turnes out that the PP/MFAPP composites have better tensile properties compared to PP/APP.