疏水阻燃微胶囊的制备及其在牛皮纸中的应用

目的为改善聚磷酸铵的阻燃性及热稳定性,降低其对纸材物理性能的影响,制备一种疏水阻燃微胶囊。方法以聚磷酸铵、季戊四醇、铜改性4A分子筛为芯材,以海藻酸钠和氯化钙为原料制备壁材,在外壳包覆SiO₂微粒,并制备阻燃牛皮纸。采用极限氧指数（LOI）测试、垂直燃烧测试（VBT）、烟密度测试（SDT）、微型量热仪（MCC）和热重分析（TG）表征阻燃纸的阻燃性和热稳定性,采用场发射扫描电镜（SEM）、透射电镜（TEM）表征疏水阻燃微胶囊的微观形貌,用傅里叶变换红外光谱（FTIR）表征试样的官能团特征,并根据国标测定纸张试样的抗张强度和撕裂度。结果涂布疏水阻燃微胶囊的牛皮纸试样的极限氧指数达到了36.3%,与空白组相比,烟释放总量、热释放速率峰值和热释放总量分别降低了42.44%、52.4%、36.1%,抗张强度和撕裂度分别提高了8.2%、177.1%,疏水阻燃微胶囊的表面形貌特征、元素分析结果以及红外光谱分析结果可表明,阻燃剂被成功包覆,并且SiO2微粒成功沉积在微胶囊壁材的表面。结论疏水阻燃微胶囊能有效改善阻燃剂的阻燃性、抑烟性和热稳定性,提高了基材的力学强度,降低了微胶囊的...

Preparation of Hydrophobic Flame Retardant Microcapsules and Application in Kraft Paper

The work aims to prepare the hydrophobic flame retardant microcapsules to improve the flame retardance and thermal stability of APP and reduce its effect on the physical property of paper. The core of microcapsules was prepared by ammonium polyphosphate, pentaerythritol and modified 4A molecular sieve, while the wall of microcapsules was prepared with sodium alginate and calcium chlorid and then coated with SiO2 particles to prepare flame retardant kraft paper. The flame retardance and thermal stability of the flame retardant kraft paper were characterized by limiting oxygen index (LOI) test, vertical burning test (VBT), smoke density test (SDT), micro calorimeter (MCC) and thermogravimetric (TG) analysis. The morphology of hydrophobic flame retardant microcapsules was characterized by field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The features of functional groups of samples were characterized with Fourier transform infrared spectroscopy. The tensile strength and tear strength of paper samples were tested according to the national standard. The limiting oxygen index of kraft paper coated with hydrophobic flame retardant microcapsules increased to 36.3%. Compared with the control group, the total smoke release, peak heat release rate and total heat release decreased by 42.44%, 52.4% and 36.1% respectively, and the tensile strength and tear strength increased by 8.2% and 177.1% respectively. According to the morphology characteristics, elemental analysis and infrared spectroscopy, the flame retardants were successfully coated and SiO2 particles were successfully deposited on the shell of microcapsules. The hydrophobic flame retardant microcapsules can effectively improve the flame retardance, smoke suppression performance and thermal stability of the flame retardants, thus enhancing the mechanical strength of the treated materials and reducing the hygroscopicity of the microcapsules.