What is the difference between silicone sealant and polyurethane sealant?

What is the difference between silicone sealant and polyurethane sealant?

There are significant differences between silicone sealants and polyurethane sealants in terms of chemical composition, physical properties, and applicable scenarios. ?

chemical composition
?Silicone sealant?: The main component is silicone, which has the characteristics of high temperature resistance, weather resistance and good electrical insulation?.
?Polyurethane sealant?: The main component is polyurethane, which has good adhesion and wear resistance?.
physical properties
?Temperature resistance?: Silicone sealants remain stable at high temperatures up to 300°C, while polyurethane sealants may decompose or lose performance at high temperatures?.
?Weather resistance?: Silicone sealant has excellent weather resistance and can resist ultraviolet rays, oxygen, water and atmospheric pollutants, making it suitable for outdoor environments?.
?Elasticity?: Both have a certain degree of elasticity and can withstand deformation and vibration without breaking?.
?Adhesion?: Polyurethane sealant has good adhesion to a variety of materials, while silicone sealant has relatively poor adhesion properties?.
Applicable scenarios
?Silicone sealant?: Commonly used in electronics, construction and outdoor fields, suitable for occasions requiring high temperature resistance and weather resistance?.
?Polyurethane sealant?: Commonly used in construction, automobile and industrial fields, suitable for occasions requiring high strength and high wear resistance?.
Comparison of advantages and disadvantages
?Silicone sealant?: The advantages include high temperature resistance, good weather resistance, and good electrical insulation; the disadvantage is that the bonding performance is relatively poor?.
?Polyurethane sealant?: The advantage is strong bonding performance, good wear resistance, and suitable for high tension or vibration load situations; the disadvantage is poor performance in high temperature and high humidity environments?.
To sum up, the choice between silicone sealant and polyurethane sealant should be decided based on the specific usage scenarios and requirements.