Question

Weather resistance of high impact polystyrene can be improved by blending polystyrene with:

• A. Styrene butadiene rubber
• B. Natural rubber
• C. Ethylene propylene rubber
• D. Nitrile rubber

Hint:

To improve the weather resistance of HIPS, choose rubbers that offer excellent resistance to UV degradation, oxidation, and moisture, such as Styrene butadiene rubber (SBR) and Ethylene propylene rubber (EPR).

Answer 1

The Correct Option is C

High impact polystyrene (HIPS) is known for its strength and durability but lacks good weather resistance. To improve its weather resistance, blending it with specific rubbers helps enhance its performance.
- Styrene butadiene rubber (SBR) (Option A) is often used for blending with HIPS to improve its impact strength and weather resistance. The addition of SBR improves the material's ability to withstand outdoor exposure to weathering agents like UV radiation and moisture.
- Ethylene propylene rubber (EPR) (Option C) is another excellent choice for improving weather resistance due to its high resistance to oxidation, ozone degradation, and UV exposure. This blend enhances the longevity of the material in outdoor environments.
Thus, both (A) Styrene butadiene rubber and (C) Ethylene propylene rubber are correct answers. Other rubbers like natural rubber and nitrile rubber (Options B and D) are less effective in improving weather resistance in polystyrene compared to the above-mentioned options.