Explanation: Raincoats are designed to protect the wearer from rain and maintain dryness. The material used in raincoats must be waterproof to prevent water from penetrating the fabric and reaching the wearer's body. Rubber is a material that is impermeable to water, making it an ideal choice for raincoats.
Rubber is a natural or synthetic material that is known for its elasticity and waterproof properties. When used in raincoats, rubber can be applied in various forms, such as rubberized fabric or as a coating on other materials. The rubber coating creates a barrier that prevents water from passing through the fabric, ensuring that the wearer remains dry.
In contrast, materials like silk and cotton are not suitable for raincoats because they are absorbent. Silk and cotton fibers can absorb water, which would make the wearer wet in the rain. These materials are commonly used in clothing for their comfort and breathability, but they lack the necessary waterproof properties required for rain protection.
Rubber has been used in raincoats for many years, and while modern raincoats may incorporate other waterproof materials like Gore-Tex or other synthetic fabrics, rubber remains a fundamental material in the construction of raincoats. The waterproof properties of rubber make it a reliable choice for rain protection, ensuring that the wearer stays dry in wet conditions.
In summary, rubber is the correct material used to make raincoats due to its impermeable and waterproof properties, which are essential for keeping the wearer dry in the rain. Other materials like silk and cotton are not suitable for raincoats because they absorb water, making them ineffective for rain protection.