1. Characteristic Analysis of Phenyl Raw Rubber
Phenyl raw rubber is a silicone rubber material containing phenyl side groups. Its properties are closely related to the phenyl content:

Flexibility: The flexibility of phenyl raw rubber is negatively correlated with its phenyl content. Low-phenyl silicone rubber (phenyl content 5-15%) has the best flexibility, and its curing temperature can be as low as -115℃. Increasing the phenyl content increases the rigidity of the molecular chain and reduces flexibility.

Freezing Point of Molecular Chain: Low-phenyl silicone rubber can maintain elasticity below -100℃, and its freezing point is extremely low. The freezing points of medium-phenyl silicone rubber (phenyl content 15-25%) and high-phenyl silicone rubber (phenyl content above 30%) increase with increasing phenyl content.

2. Characteristic Analysis of Methyl Raw Rubber
Methyl raw rubber (methyl silicone rubber) is a basic silicone rubber material with the following performance characteristics:
Flexibility: The methyl raw rubber molecular chain contains methyl side chains, which allow it to maintain a certain degree of flexibility at low temperatures without becoming brittle. Its main chain has a saturated single-bond structure with high internal rotational freedom, exhibiting good flexibility.

Molecular Chain Freezing Point: Although the search results do not explicitly provide freezing point data for methyl raw rubber, based on its flexibility, it is inferred that methyl raw rubber should have good low-temperature performance and maintain elasticity over a wide temperature range.

3. Comprehensive Comparative Analysis
Characteristics: Phenyl Raw Rubber vs. Methyl Raw Rubber
Flexibility: Good flexibility at low phenyl content, decreasing with increasing phenyl content. Overall good flexibility; methyl side chains provide stable flexibility.
Molecular Chain Freezing Point: Low-phenyl type can reach below -100℃. Presumably has good low-temperature performance (specific data not yet clear).
Applicable Temperature Range: Excellent performance in extremely low temperatures. Suitable for a wide temperature range.
Special Properties: Radiation resistance, ablation resistance (high-phenyl type). Stable basic properties, good processability.

4. Application Recommendations
Extreme Low Temperature Applications: Prioritize low-phenyl-content phenyl raw rubber (5-15% phenyl), as it has the lowest freezing point and best flexibility.

General Applications: Methyl raw rubber offers better cost-effectiveness and processing performance, suitable for most general applications.

Special Environments: High-phenyl-content phenyl raw rubber is suitable for special requirements such as radiation resistance and ablation resistance.

5. Differences in Molecular Structure: The phenyl side groups in phenyl raw gum increase the rigidity and steric hindrance of the molecular chain, while the methyl side chains in methyl raw gum are smaller, allowing for greater freedom of molecular chain movement. This structural difference directly leads to the difference in their flexibility and low-temperature performance.