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化学学报
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化学学报 ›› 2010, Vol. 68 ›› Issue (01): 19-26. 上一篇    下一篇

研究论文

多层核-壳结构P(AM-co-MAA)/W/UF复合微球制备研究

宁向莉，张颖*，吴华涛   

  1. (应用表面与胶体化学教育部重点实验室 陕西师范大学化学与材料科学学院 西安 710062)
  • 投稿日期:2009-03-05 修回日期:2009-07-17 发布日期:2009-09-07
  • 通讯作者: 张颖 E-mail:zhangy@snnu.edu.cn
  • 基金资助:

    陕西省自然科学基金(NO. 2007E106)和陕西师范大学研究生培养创新基金(2008CXS026)资助项目.

Preparation of P(AM-co-MAA)/W/UF Composite Microspheres with Multi-layer Core-shell Structures

Ning Xiangli, Zhang Ying*, Wu Huatao   

  1. (Key Laboratory of Applied Surface and Colloid Chemistry (Ministry of Education), School of Chemistry and Materials Science, Shaanxi Normal University, Xi'an 710062)
  • Received:2009-03-05 Revised:2009-07-17 Published:2009-09-07
  • Contact: Ying ZHANG E-mail:zhangy@snnu.edu.cn

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以反相悬浮聚合技术合成的丙烯酰胺(acrylamide, AM)和甲基丙烯酸(methacrylic acid, MAA)共聚高分子微凝胶P(AM-co-MAA)为模板, 通过离心沉积法将微米级钨粉沉积于高分子微凝胶表面, 得到具有核-壳结构的P(AM-co-MAA)/W复合微球材料; 再以P(AM-co-MAA)/W复合微球为模板, 通过控制甲醛和尿素的缩聚反应在模板与油/水相界面进行, 制备得到了具有多层核-壳结构的高分子/钨/脲醛树脂[P(AM-co-MAA)/W/Urea-formaldehyde resin]复合微球材料. 利用扫描电子显微镜(SEM)、红外(FT-IR)、X射线衍射(XRD)和热分析(TGA)等手段对复合微球进行了表征. 实验结果表明, 外壳层脲醛树脂的包覆量、复合微球的表面形貌可通过改变甲醛和尿素溶液的浓度、甲醛和尿素的物质的量之比等因素进行控制. 复合微球的导电性测试结果表明, P(AM-co-MAA)/W复合微球表面壳层脲醛树脂包覆前后, 其电导率由1.9×10－3降低为0.9×10－8 S•m－1. 该研究获得的三层核-壳复合微球材料其外层脲醛树脂的包覆较为完整、致密, 其导电性接近于绝缘材料, 为含钨复合微球作为电子元件的抗辐射涂层材料打下了基础.

关键词: 高分子微凝胶, 钨粉, 脲醛树脂, 模板法, 核-壳结构

Using poly(acrylamide-co-methacrylic acid) copolymer microgels prepared by a reverse suspension polymerization technique as templates, poly(acrylamide-co-methacrylic acid)/tungsten [P(AM-co- MAA)/W] composite microspheres with core-shell structures were fabricated by centrifugal deposition of tungsten powder on the polymer template surface. Then P(AM-co-MAA)/W/UF(urea-formaldehyde) resin composite microspheres with multi-layer core-shell structures were produced via polycondensation between formaldehyde and urea conducted at the interface between the P(AM-co-MAA)/W template and oil/water phase. The prepared composite microspheres were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectrometry (FT-IR) and thermogravimetric analysis (TGA) techniques. It was demonstrated that the amount of UF resin coated and surface morphologies of P(AM-co- MAA)/W/UF composite microspheres could be controlled by varying the concentrations of formaldehyde and urea solutions and the molar ratio of formaldehyde to urea. The electric conductivity of prepared composite microspheres significantly decreased from 1.9×10－3 to 0.9×10－8 S•m－1, before and after coating of urea-formaldehyde resin layer on the surface of P(AM-co-MAA)/W composite microspheres. The prepared composite microspheres with the three-layer core-shell structures are of the quite full and dense coating layer, and its conductivity is nearly close to the insulating materials. All these characteristics of the composite microspheres containing tungsten materials would establish a better foundation for the application as the anti-radiation coating materials of the electronic component.

Key words: polymer microgel, tungsten powder, urea-formaldehyde resin, template method, core-shell structure