Resin Composites
Resin-based composites feature light weight, high strength and corrosion resistance. However, in recent years, the material industry and pillar industries of the national economy have put forward higher and higher requirements for the performance of resin-based materials. How to synthesize high-performance resin-based composites has become an important topic for the material industry and enterprises. The advent of nano-silica provides new opportunities for the synthesis of resin-based composites and a new approach for the modification of traditional resin-based materials. As long as nano-silica particles are fully and uniformly dispersed in resin materials, the performance of resin-based materials can be comprehensively improved.
1. Improve strength and elongation. Epoxy resin is a basic resin material. Adding nano-silica to epoxy resin is structurally different from epoxy resin-based composites added with coarse-grained silica (such as silica). Coarse-grained SiO₂ is usually added as a reinforcing agent, mainly distributed between the chains of polymer materials. Due to the serious insufficient coordination, huge specific surface area and oxygen deficiency on the surface, nano-silica shows extremely strong activity and easily bonds with the oxygen of epoxy cyclic molecules, improving the intermolecular bonding force. At the same time, some nano-silica particles are still distributed in the gaps of polymer chains. Compared with coarse-grained SiO₂ particles, it shows high fluidity, thus greatly improving the strength, toughness and ductility of epoxy resin materials added with nano-silica.
2. Improve wear resistance and surface smoothness of materials. Nano-silica particles are 100-1000 times smaller than SiO₂, and adding them to epoxy resin is conducive to wire drawing. Due to the high fluidity and small size effect of nano-silica, the material surface becomes denser and finer, the friction coefficient decreases, and the high strength of nano-particles greatly enhances the wear resistance of materials.
3. Aging resistance. A fatal weakness of epoxy resin-based composites in use is poor aging resistance, mainly caused by medium and long-wave ultraviolet radiation in the 280-400nm band of solar radiation. Its damage to resin-based composites is very serious, and the degradation of polymer chains leads to rapid aging of resin-based composites. Nano-silica can strongly reflect ultraviolet rays. Adding it to epoxy resin can greatly reduce the degradation effect of ultraviolet rays on epoxy resin, thus delaying the aging of materials.
Plastics: Using the light transmittance and small particle size of nano-silica can make plastics more compact. After adding silica to polystyrene plastic film, not only its transparency, strength and toughness are improved, but also its waterproof and aging resistance are significantly enhanced. By adding a small amount of nano-silica to ordinary polyvinyl chloride plastic, the hardness, smoothness and aging resistance of the produced plastic steel doors and windows are greatly improved. Modifying ordinary polypropylene plastic with nano-silica, the main technical indicators (water absorption, insulation resistance, compression set, flexural strength, etc.) all reach or exceed the performance indicators of engineering plastic nylon 6, realizing the replacement of nylon 6 with polypropylene railway accessories. The product cost is greatly reduced, and its economic and social benefits are very significant.