Preparation of Microencapsulated Red Phosphorus and Its Flame-Retardant Application in PP Composites
JIANG Wen-jun1,2, LI Zhe-zhao2，ZHANG Chun-xiang1, FANG Jin1, YANG Xu-jie1*, LU Lu-de1, PU Long-juan1
1. Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education，Nanjing University of Science and Technology，Nanjing 210094, China 2. Changzhou Hongzhelan Wire and Cable Co. Ltd., Changzhou 213101，China
Abstract：In the present study, the melamine-formaldehyde prepolymer (MFP) was first synthesized at pH 8-8.5 under about 80 ℃ with melamine, formaldehyde, triethanolamine and methanol as the starting materials. Subsequently, the microencapsulated red phosphorus (MRP) was successfully prepared by in-situ polymerization at pH 5.5 under 65 ℃, using MFP and red phosphorus (RP) powders as raw materials, and potassium persulphate (KPS) as catalyst. The obtained products were detected by differential scan calorimetry (DSC), scanning electron microscope (SEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). It was found that KPS is useful in enhancing the reaction activity of MFP, which can make RP be well encapsulated by melamine-formaldehyde resin (MF) and reduce the reaction time. The DSC, SEM and XPS results show that it won’t get well-encapsulated MRP only under acidic condition and without any KPS. When a proper quantity of KPS is employed, the RP particles can be almost completely-encapsulated by MF and the peak temperature of oxidation reaction for MRP is 480 ℃, which is much higher than that of RP, extending the applications for MRP. The FTIR spectrum demonstrates that the coating material on the surface of RP accurately is MF, in agreement with the reference. Polyproplene (PP) composites with different formulations were prepared by melt extrusion. It was shown that the flame-retardant efficiencies are very low when the PP composites only contain MRP or MH. However, the flame-retardant property can obviously improve if MRP and MH are both used in the PP composites. When PP∶MRP∶MH=100 (phr)∶15 (phr)∶50 (phr), the limited oxygen index of the MRP/MH/PP composite is 26%, and vertical firing ranks UL-94 V-0. In addition, the possible flame-retardant mechanism of the PP composites has also been discussed, and further verified by FTIR and Raman spectroscopy.
Key words：Potassium persulphate;Melamine-formaldehyde resin;Microencapsulated red phosphorus;Flame-retardant property
蒋文俊1，2, 李哲曌2，张春祥1, 方 劲1, 杨绪杰1*, 陆路德1, 浦龙娟1 . 微胶囊红磷的制备及在PP中的阻燃应用[J]. 光谱学与光谱分析, 2010, 30(05): 1329-1335.
JIANG Wen-jun1,2, LI Zhe-zhao2，ZHANG Chun-xiang1, FANG Jin1, YANG Xu-jie1*, LU Lu-de1, PU Long-juan1 . Preparation of Microencapsulated Red Phosphorus and Its Flame-Retardant Application in PP Composites . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2010, 30(05): 1329-1335.
[1] CHEN Hai-qun, ZHU Jun-wu, WANG Hai-jing, et al(陈海群, 朱俊武, 王海靖, 等). Chinese Journal of Applied Chemistry(应用化学), 2004, 21(11): 1141. [2] Wu Q, Lu J P, Qu B J. Polymer International, 2003, 52(8): 1326. [3] CHEN Hai-qun, BEI Feng-li, WANG Zhi-cheng, et al(陈海群, 卑凤利, 王志成, 等). Chinese Journal of Organic Chemistry(无机化学学报), 2004, 20(8): 905. [4] Wang H T, Meng X F, Wen B, et al. Materials Letters, 2008, 62(21-22): 3745. [5] GUAN Ying, GUO Xi-hua, DI Li-jie, et al(关 颖, 郭西华, 邸立杰, 等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2008, 28(6): 1283. [6] LIU Feng-qi, MAO Kun-yuan, ZHANG De-he, et al(刘凤岐, 毛坤元, 张德和, 等). Chinese Journal of Analytical Chemistry(分析化学), 1990, 18(5): 409. [7] LI Feng, ZHU Quan-shou, et al(李 峰, 朱铨寿, 等). Formaldehyde and Its Derivation(甲醛及其衍生物). Beijing: Chemical Industry Press(北京: 化学工业出版社), 2006. 248. [8] Bone J S. Development and Characterization of the Interlayer Chemistry of Layered Double Hydroxides. Exter: University of Exter, 1995. [9] Fichera M A, Braun U, Schartel B, et al. Journal of Analytical and Applied Pyrolysis, 2007, 78(2): 378. [10] JIN Lan-ying, JIANG Yan-xia, LIAO Hong-gang, et al(金兰英, 姜艳霞, 廖宏刚, 等). Chemical Journal of Chinese Universities(高等学校化学学报), 2009, 30(4): 767. [11] Jiang W J, Hua X, Han Q F, et al. Powder Technology, 2009, 191(3): 227. [12] ZHOU Jian-guo, WANG Ying-ling, ZHAO Feng-ying, et al(周建国, 汪应灵, 赵凤英, 等). Chinese Journal of Organic Chemistry(无机化学学报), 2005, 21(2): 221. [13] Tian Y, Wang G, Li F, Evans D G. Materials Letters, 2007, 61(8-9): 1662. [14] ZHANG Li-hua, WU Di, CHEN Ya-shao, et al(张丽华, 吴 迪, 陈亚芍, 等). Chemical Journal of Chinese Universities(高等学校化学学报), 2008, 29(9): 1854. [15] Tuistra F, Koeing J L. Journal of Composite Materials, 1970, 4: 492.
