Partially-Perforated Self-Reinforced Polyurea Foams
Partially-Perforated Self-Reinforced Polyurea Foams
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DOI：
10.3390/app10175869
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发表时间：
2020-09-01
影响因子：
2.7
通讯作者：
Youssef, George
中科院分区：
文献类型：
--
作者：
Do, Sophia;Nha Uyen Huynh;Youssef, George
本文报道了通过自发泡工艺合成的聚脲泡沫的独特微观结构，其结合了开孔和闭孔聚合物泡沫的优点。后者是二胺固化剂、异氰酸酯和去离子水在环境条件下的剧烈机械混合的结果，其可以按需调节以产生可变密度的聚脲泡沫。球形、半封闭的微孔结构在孔表面上具有大的穿孔，这是由于相邻孔的同时膨胀和孔的底表面处的小孔。这导致聚脲泡沫的部分穿孔微孔结构。作为制造过程的副产品，聚脲微球成核并存款在泡沫的内部孔壁上，起到增强作用。由于细胞壁和微球由聚脲制成，因此产生的增强效果克服了不同相邻材料的基本界面问题。部分穿孔，自增强的聚脲泡沫相比，传统的同行在生物力学的影响情况下的性能。一个分析模型被开发来解释与增强微球相关的硬化效应。模型结果表明，加强的微单元表现出，平均而言，类似的30%以上的刚度比其贫瘠的对应。
This paper reports the unique microstructure of polyurea foams that combines the advantages of open and closed cell polymeric foams, which were synthesized through a self-foaming process. The latter was the result of aggressive mechanical mixing of diamine curative, isocyanate, and deionized water at ambient conditions, which can be adjusted on-demand to produce variable density polyurea foam. The spherical, semi-closed microcellular structure has large perforations on the cell surface resulting from the concurrent expansion of neighboring cells and small holes at the bottom surface of the cells. This resulted in a partially perforated microcellular structure of polyurea foam. As a byproduct of the manufacturing process, polyurea microspheres nucleate and deposit on the inner cell walls of the foam, acting as a reinforcement. Since cell walls and the microspheres are made of polyurea, the resulting reinforcement effect overcomes the fundamental interfacial issue of different adjacent materials. The partially perforated, self-reinforced polyurea foam is compared to the performance of traditional counterparts in biomechanical impact scenarios. An analytical model was developed to explicate the stiffening effect associated with the reinforcing microspheres. The model results indicate that the reinforced microcell exhibited, on average, similar to 30% higher stiffness than its barren counterpart.