高等学校化学学报 ›› 2016, Vol. 37 ›› Issue (1): 180.doi: 10.7503/cjcu20150510

• 高分子化学 • 上一篇    下一篇

具有环状结构的二氧化硅微聚集体的制备、 表征及应用

田敏1,2, 杨应娟1,2, 何文涛1(), 李娟1, 秦舒浩1, 于杰1,2()   

  1. 1. 国家复合改性聚合物材料工程技术研究中心, 贵阳 550014
    2. 贵州大学材料与冶金学院, 贵阳 550025
  • 收稿日期:2015-06-30 出版日期:2016-01-10 发布日期:2015-11-17
  • 基金资助:
    国家自然科学基金(批准号: 51263003)和贵州省高层次创新型人才培养项目(批准号: 黔科合人才[2015]4037号)资助

Preparation, Characterization and Application of Silica Nanoparticle Micro-aggregates with Circular Structure

TIAN Min1,2, YANG Yingjuan1,2, HE Wentao1,*(), LI Juan1, QIN Shuhao1, YU Jie1,2,*()   

  1. 1. National Engineering Research Center for Compounding and Modification of Polymeric Materials, Guiyang 550014, China
    2. College of Material and Metallurgy of Guizhou University, Guiyang 550025, China
  • Received:2015-06-30 Online:2016-01-10 Published:2015-11-17
  • Contact: HE Wentao,YU Jie E-mail:wentaohe@aliyun.com;yujiegz@126.com
  • Supported by:
    † Supported by the National Natural Science Foundation of China(No.51263006) and the High-level Innovative Talent-training Program in Guizhou Province, China(No.[2015]4037)

摘要:

通过溶胶-凝胶法制备二氧化硅溶胶, 并采用喷雾干燥法对其进行形态调控. 扫描电镜(SEM)结果表明, 喷雾干燥使二氧化硅颗粒发生了形态重组, 形成均匀的具有环状结构的二氧化硅微聚集体(PC16MS). 通过熔融共混制备了二氧化硅/聚丙烯(PP)纳米复合材料, 研究了PC16MS的加入对其微观结构、 晶体结构、 结晶行为、 球晶形态、 结晶成核密度和球晶生长速率等方面的影响. 采用差示扫描量热(DSC)、 偏光相差显微镜(POM)和广角X射线衍射(WAXRD)分析表明, 在PP结晶初始阶段, PC16MS的加入大幅度提高了基体材料的成核密度, 且使晶粒细化, 缩短了结晶时间; 当添加2%(质量分数)的PC16MS时, 复合材料的结晶温度相对于纯PP提高了10.4 ℃, 成核效率达到39.1%, 优于大部分无机成核剂的成核效率. 在相同条件下, 添加2%未经过喷雾干燥处理的纳米二氧化硅(NC16MS), 复合材料的结晶温度相对于纯PP提高3.26 ℃, 成核效率达到12.3%. 结果表明, 喷雾干燥使二氧化硅颗粒发生了形态重组, 形成的均匀介稳态微聚集体在熔融挤出过程中重新分散成纳米粒子, 从而有效提高了二氧化硅作为成核剂的成核效率.

关键词: 纳米二氧化硅, 喷雾干燥, 聚丙烯, 结晶行为

Abstract:

Silica sol was firstly prepared by means of sol-gel method and then dried by spray drying method. Scanning electronic microscope(SEM) results demonstrated that the initially obtained nanoparticles were recomposed to monodispersed circular aggregates with size about 20 μm. The silica/polypropylene(PP) composite was prepared and investigated by means of differential scanning calorimetry(DSC), polarizing microscopy(POM), wide angle X-ray diffraction(WAXRD) and transmission electron microscopy(TEM). The micron circular aggregates, PC16MS, broke up and re-dispersed into nanoparticles with size less than 200 nm in the PP matrix during melt-compounding. The effect of the addition of PC16MS on spherulite growth of iPP was investigated using POM. The results demonstrated that the addition of PC16MS can significantly accelerate the primary nucleation process, minimize the spherulite radius and shorten the crystallization time. A linear relationship was observed between the radius of spherulites and crystallization time at the initial stage of crystallization. With the addition of 2%(mass fraction) PC16MS, the crystallization temperature increased by 10.4 ℃ and the nucleation efficiency reached 39.1% compared to pristine iPP, suggesting PC16MS can be used as an effective nucleating agent for PP.

Key words: Silica nanoparticles, Spray drying, Polypropylene, Crystallization

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