Glass-fiber reinforced composites are lightweight and stable 

In glass fiber composites, glass fibers and plastic couple to form a valuable bond: The glass fibers imparts the plastic with mechanical strength, while the plastic protects and supports the glass fibers.  

This has many additional benefits: Glass-fiber reinforced plastics are lighter and more flexible than higher-density materials such as metals. The lower weight makes it possible, for example, to reduce fuel consumption in automobiles or airplanes. Deviating designs are also possible thanks to the properties. Moreover, using glass-fiber reinforced plastics eliminates the risk of corrosion.  

As a result of the above, composites are suitable for use in a wide range of applications. In aviation, vehicle construction and other high-tech industries, they are key to reducing the materials and energy needed through lightweight designs. In large-scale construction projects such as for wind turbines, the polymer-jacketed glass fibers provide strong and performance-stable reinforcements – comparable to the human skeleton, which is held together by muscles and tendons to ensure the constant mechanical stability of the human body.  

To this end, glass fiber products can be used in a variety of forms, such as endless glass fibers, chopped strands, mats, woven and nonwoven fabrics and yarns, or as industrial textiles with complex, high-functional weave patterns. 

Manufacturing these composites is a challenge: Because moisture results in the poor bonding of natural glass surfaces to polymers, the surfaces of glass fibers must be modified immediately after extrusion from the melt. During sizing, various Dynasylan® products ensure that the surface of the glass fibers are chemically modified and primed for coupling permanently. This enables organic plastics to form a stronger, permanent bond. 

Using the functional silicon groups of a silane impregnates the glass fiber surface to prevent delamination caused by salt and water – the compound material thus becomes more resistant to moisture. In turn, the functional organic groups of the silane enable coupling and a permanent interaction with an organic polymer or resin – adhesion improves significantly as a result. The size using silanes thus transfers the strength of the glass fibers to the polymer, and the glass fibers in turn are protected mechanically and chemically. 

Only silanes provide this combination of effects. Via their use, polymers can be specifically “equipped” with the mechanical properties required for the respective application. 

How long the bond lasts depends on whether the right silane has been selected. For example, the best results are obtained in polyester and vinyl ester resins when sized using vinyl and methacrylate-based products. And epoxysilanes, aminofunctional silanes and water-based silane-hydrolysates from the Dynasylan® HYDROSIL range yield outstanding performance with epoxy resins. 

The experts from Evonik can tailor the use of technically complex silanes in partnership with customers to ensure that the silanes contribute effectively toward the end product's performance. 

• Improves the adhesion between glass fibers and polymers 
• The chemical coupling of the polymer matrix and fibers promotes the mechanical performance of the composites 
• Optimum choice of functional silanes for each plastic, polymer or resin 
• Silanes increase resistance to moisture and reduce the aging of the glass fibers in the polymer matrix  
• Antistatic effects of the coating to enhance the electrical properties of the composites