改性凹凸棒石/苏木复合颜料的制备和性能

Preparation and properties of modified palygorskite/sappanwood hybrid pigments

摘要:

分别用盐酸处理凹凸棒石（PAL）制备酸洗凹凸棒石（PA），对PA进行有机改性（壳聚糖、阳离子表面活性剂双十八烷基二甲基氯化铵、硅烷偶联剂KH550）制备三种改性PAL（PCS、PDO、PKH），最后以PA、PCS、PDO、PKH负载苏木色素制备四种改性凹凸棒石/苏木复合颜料（简称复合颜料，全文同）PAS、PCSS、PDOS、PKHS。通过FTIR、XRD、TEM、BET、TG及颜色表征，探究不同改性方法对复合颜料的粉体学性质、稳定性和生物安全性等性能的影响。结果表明，有机改性和苏木色素负载并未改变PAL的晶相结构和纤维形态；复合颜料显著提高了苏木色素的热稳定性、酸碱稳定性和遮盖性能。壳聚糖改性凹凸棒石制备的复合颜料（PCSS）表现出较佳的综合性能：热稳定性（120 ℃处理6 h，色差值ΔE<6）、酸碱稳定性最好（pH=5~9浸泡24 h，色差值ΔE<4），水和乙醇溶出度最低（2.13和1.02 mg/g），生物安全性高（无血管刺激性）。

Abstract:

Palygorskite (PAL) was treated with HCl to prepare pickling palygorskite (PA), and modified PAL (PCS, PDO, PKH) were prepared by organic modification of PA (chitosan, cationic surfactant dioctadecyl dimethyl ammonium chloride, silane coupling agent KH550). Finally, modified palygorskite/sappanwood hybrid pigments (short for hybrid pigment, the same as full text) PAS, PCSS, PDOS, PKHS were prepared by PA, PCS, PDO, PKH loaded with sappanwoood dye extract. Through FTIR, XRD, TEM, BET, TG and color characterization, the effects of different modification methods on the powder properties, stability and biosafety of the prepared hybrid pigments were investigated. The results showed that organic modification and sappanwoood dye extract loading do not change the crystal structure and fiber morphology of PAL. The hybrid pigments significantly improved the thermal stability, acid-base stability and covering power of sappanwoood dye extract. Hybrid pigment (PCSS) prepared by chitosan modified PAL showed better comprehensive properties: thermal stability (ΔE<6 on exposure to 120 ℃ for 6 h), the best acid-base stability (ΔE<4 on soaking in pH=5~9 solution for 24 h), the lowest water-alcohol dissolution rate (2.13 mg/g in water and 1.02 mg/g in ethanol), high biosafety (non-irritant to vascular membrane).