Microencapsulation of n‐hexadecanol by in situ polymerization of melamine–formaldehyde resin in emulsion stabilized by styrene–maleic anhydride copolymer
Microencapsulation of n‐hexadecanol by in situ polymerization of melamine–formaldehyde resin in emulsion stabilized by styrene–maleic anhydride copolymer
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DOI：
10.1002/er.3276
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发表时间：
2015-04
影响因子：
4.6
通讯作者：
D. Yin;Li Ma;W. Geng;Baoliang Zhang;Qiuyu Zhang
中科院分区：
文献类型：
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作者：
D. Yin;Li Ma;W. Geng;Baoliang Zhang;Qiuyu Zhang
以三聚氰胺甲醛树脂为壳，正十六醇为核，采用原位聚合法制备了储能密度较高的微胶囊。采用溶液聚合的方法合成了苯乙烯-马来酸酐(SMA)共聚物，并用氢氧化钠对其进行了水解，以提高其水溶性。这种带负电荷的SMA分子共聚物在正十六醇液滴表面自组装，并通过静电作用促进带正电的三聚氰胺-甲醛预聚体在液滴表面的沉淀。用扫描电子显微镜、傅里叶变换红外光谱、热重分析、差示扫描量热法和气相色谱等手段对产物的形貌、化学结构、组成和热性能进行了表征。结果表明，所制得的微胶囊相变材料呈球形分散。乳化剂用量、壳核比、溶液pH值对微胶囊化效果有显著影响。在料液比为8%，料液比为3.3：10，pH为4.0的聚合条件下，制得了球状正十六醇MPCM，其核含量为79.1%，熔融热为171J g−1，熔融温度为51℃左右。基于SMA稳定乳液的原位聚合为制备各种以脂肪醇为芯材的微胶囊开辟了一条新的途径。版权所有©2014 John Wiley&Sons，Ltd.
Microcapsules with high thermal energy storage density were synthesized by in situ polymerization using melamine–formaldehyde resin as shell and n‐hexadecanol as core. Styrene–maleic anhydride (SMA) copolymer was synthesized by solution polymerization and hydrolyzed by NaOH to enhance its water solubility. This negatively charged SMA molecular copolymer self‐assembles on the surface of n‐hexadecanol droplets and facilitates the precipitation of positively charged melamine–formaldehyde prepolymer onto the droplet surface electrostatically. The morphology, chemical structure, composition, and thermal properties were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, thermal gravimetric analysis, differential scanning calorimetry, and gas chromatography, respectively. The results show that the obtained microencapsulated phase‐change material (MePCM) dispersed individually with a spherical shape. Amount of emulsifier, ratio of shell–core material, and pH value of solution have a significant effect on the microencapsulation. Under optimum condition of 8% SMA to core material, 3.3:10 of shell–core material in feed, and polymerization under pH 4.0, spherical n‐hexadecanol MePCMs with core content of 79.1% and melting enthalpy of 171 J g−1 at around 51°C were prepared. In situ polymerization based on SMA‐stabilized emulsion opens up a route to prepare a variety of microcapsules with aliphatic alcohol as core material. Copyright © 2014 John Wiley & Sons, Ltd.