Improving the performance of SBR/NR blended rubber: the key role of nano-magnesium hydroxide

In the rubber industry, blends of SBR (styrene-butadiene rubber) and NR (natural rubber) are widely used due to their excellent physical and chemical properties. By adding nano magnesium hydroxide, we can not only improve its flame retardant properties, but also enhance its mechanical properties. This article will explore the application of nano magnesium hydroxide in SBR/NR blends and how to optimize its properties through modification.

Raw material preparation and surface modification

Selection of SBR and NR:

ｓｅｌｅｃｔ suitable SBR and NR, and determine their Mooney viscosity and vulcanization system according to application requirements.

Nano magnesium hydroxide:

ｓｅｌｅｃｔ nano magnesium hydroxide powder with high purity and uniform particle size distribution, and perform necessary surface modification to improve its dispersibility and compatibility in rubber.

Surface modification method:

Wet modification: The surface modifier is evenly distributed on the surface of nano magnesium hydroxide through ultrasonic treatment, and then washed and dried.

Dry modification: Mix nano magnesium hydroxide and surface modifier in a high-speed mixer and then dry.

Mixing and vulcanization process

Mix the modified nano magnesium hydroxide with SBR and NR rubber and other additives, use an open mill or internal mixer to mix, and then vulcanize and mold in a vulcanizer.

Performance test

Mechanical performance test:

Tensile performance: Tested according to ASTM D412 standard.

Hardness: Tested according to ASTM D2240 standard.

Tear strength: Tested according to ASTM D624 standard.

Compression permanent deformation: Tested according to ASTM D395 standard.

Flame retardant performance test:

Vertical burning test (UL-94): Evaluate the vertical burning performance of the sample.

Limiting oxygen index (LOI): Tested according to ASTM D2863 standard.

Cone Calorimeter: Tested according to ISO 5660 standard.

Performance impact analysis

Nano magnesium hydroxide filling amount: Appropriate amount of filling can improve the flame retardant grade and mechanical properties of SBR/NR blended rubber, but excessive amount may lead to performance degradation.

Surface modification: The modified nano magnesium hydroxide can significantly improve the performance of SBR/NR blended rubber.

Application Examples

Automobile tires: The modified nano magnesium hydroxide improves the flame retardancy and mechanical properties of tires.

Wire and cable sheaths: Improve the flame retardancy and mechanical properties of products to meet safety requirements.

The addition and surface modification of nano magnesium hydroxide is an effective way to improve the performance of SBR/NR blends. Through precise testing and optimized processes, rubber products with excellent flame retardancy and mechanical properties can be manufactured. This method has broad application prospects in the fields of automobile tires and wire and cable sheaths.