Vinyl double caps are indispensable functional additives in the field of organic silicone material synthesis. Their molecular structure has active vinyl groups at both ends and is connected by a tetramethyl siloxane chain segment. This unique structure endows them with both reactivity and molecular control capabilities, making them the core raw material for adjusting the molecular weight of organic silicone polymers. 
In organic silicone production, vinyl double caps mainly play the dual roles of "molecular weight regulator" and "chain-end sealing agent". During the synthesis of silicone rubber and silicone oil products, they can precisely control the growth length of the polymer chain. By undergoing addition reactions with siloxane monomers, they terminate the extension of the molecular chain, thereby obtaining polymers with uniform molecular weight distribution and stable performance. For example, in the production of high-temperature vulcanized silicone rubber, adding an appropriate amount of vinyl double caps can reduce the molecular weight of the rubber and improve its processing fluidity; while in the preparation of liquid silicone rubber, its content directly affects the crosslinking density and mechanical strength of the product. 
This substance is usually a colorless transparent liquid with low viscosity and low volatility. Its boiling point is approximately 139-141℃, and the flash point is 31℃. It needs to be stored in a cool and ventilated place and kept away from fire sources. Chemically, its vinyl groups are prone to undergo silanol reactions with hydrogen-containing siloxanes, which enables it to be used as a crosslinking agent for modifying organic silicone materials, enhancing the product's resistance to high and low temperatures and adhesive properties. 
As a key auxiliary material in the organic silicone industry chain, the purity and quality of vinyl double caps directly determine the performance of downstream products. With the growth of demand for high-end organic silicone materials in fields such as new energy and electronic appliances, the research and production of high-purity (≥99.5%) vinyl double caps have become an important support for promoting the organic silicone industry towards higher value-added directions.