Diffusion and Persistence of Silicone Oil in Rubbers and Low Density Polyethylene.
PICATINNY ARSENAL DOVER N J
Pagination or Media Count:
Silicone release is used extensively in molding polymers. When it is used on the mold it gradually becomes incorporated into the polymers being molded. If the silicone can migrate it can change the bulk properties of the polymers. Even if it does not migrate and remains primarily at or near the surface, it will change surface properties, such as printability, coatability, and bondability. Therefore, it is of interest to know how much silicone remains within the polymer, whether it migrates and how easy it is to remove. Experiments with a C-14 tagged silicone mold release have given no evidence of its diffusion through polyethylene or the elastomers Buna N, Buna S, butyl, Hypalon, natural, or urethane. Hexane rapidly removed the mold release from rubbers which it did not swell urethane, Buna N, and Hypalon, Buna S, natural, and butyl rubbers retained a low level of the mold release agent, even after repeated treatment with hexane. This is presumably related to the fact that the latter three rubbers swell in the silicone. Removal of the silicone from polyethylene which has been molded against a surface coated with the mold release proved difficult.
- Organic Chemistry
- Polymer Chemistry