Study of surface-functionalized nano-SiO₂/polybenzoxazine composites

• Published in: Journal of applied polymer science 2011-05, Vol.120 (3), p.1525-1532
• Main Authors: Yan, Chun, Fan, Xinyu, Li, Juan, Zhiqi Shen, Shirley
• Format: Article
• Language: English
• Subjects: Applied sciences; Benzoxazines; Composites; Exact sciences and technology; Forms of application and semi-finished materials; Loads (forces); Materials science; mechanical properties; nanocomposite; Nanocomposites; Nanomaterials; nanosilicas; Nanostructure; polybenzoxazine; Polybenzoxazines; Polymer industry, paints, wood; Polymers; Reproduction; Technology of polymers; Thermal properties; thermal stability
• ISSN: 0021-8995; 1097-4628; 1097-4628
• DOI: 10.1002/app.33383

A series of the surface-functionalized nano-SiO₂/polybenzoxazine (PBOZ) composites was produced, and an attempt was made to improve the toughness of PBOZ material, without sacrificing other mechanical and thermal properties. A benzoxazine functional silane coupling agent was synthesized to modify the surface of nano-SiO₂ particles, which were then mixed with benzoxazine monomers to produce the nano-SiO₂-PBOZ nanocomposites. The notched impact strength and the bending strength of the nano-SiO₂-PBOZ nanocomposites increase 40% and 50%, respectively, only with the addition of 3 wt % nano-SiO₂. At the same load of nano-SiO₂, the nano-SiO₂-PBOZ nanocomposites exhibit the highest storage modulus and glass-transition temperature by dynamic viscoelastic analysis. Moreover, the thermal stability of the SiO₂/PBOZ nanocomposites was enhanced, as explored by the thermogravimetric analysis. The 5% weight loss temperatures increased with the nano-SiO₂ content and were from 368°C (of the neat PBOZ) to 379°C or 405°C (of the neat PBOZ) to 426°C in air or nitrogen with additional 3 wt % nano-SiO₂. The weight residue of the same nanocomposite was as high as 50% in nitrogen at 800°C.