外植型自修复聚合物用二氧化硅空心微球的制备方法研究

Preparation and Characterization of Silica Hollow Microcapsule for Extrinsic Self-healing Polymers

外植型聚合物自修复体系中,化学性质活泼的修复剂无法直接用原位聚合等方法直接制备微胶囊,而往往需要利用空心球负载来实现间接微胶囊化的目的。为了保证微胶囊破裂时候能在局部区域提供足够的修复剂,需要制备大直径空心微球。本文作者利用苯乙烯-丙烯酸甲酯共聚物微球为模板,正硅酸乙酯为硅源,成功制备出直径约6微米的二氧化硅空心微球。研究了溶剂抽提和高温煅烧,以及不同升温程序给二氧化硅空心结构带来的影响。通过电子扫描显微镜对产品形貌和壳层裂纹的研究,发现以1℃/min的升温速率,高温煅烧去除聚合物模板是制备外植型自修复聚合物用二氧化硅空心微球的最佳方法。

It＇s unable to prepare microcapsules directly when using high-activity healing agents/catalysts as extrinsic self-healing agents by traditional encapsulation techniques like in-situ polymerization in the oil-in-water emulsion, etc. While indirect method which hollow spheres are fabricated and then activity healing agents are infiltrated into those spheres is proved to be an effective approach. Larger diameter hollow capsules are needed to make sure sufficient healing agents can enter into fracture area. Silica hollow microspheres with diameter of 6 microns were prepared successfully using a template method which employing poly（styrene-methacrylate） particles and tetraethoxysilane as templates and precursor respectively. The effects of solvent extraction and heating procedures of high temperature calcination on the structure of hollow silica were studied. Morphological observation of hollow capsules was conducted by SEM and optimal condition for dislodging the polymer template is high temperature calcination with heating rate of 1 ℃/min.