Contaminants associated with commercial polymeric

Potential Organic Contamination Associated with Commercially Available Polymeric Sorbents... 

Reliability of the electrical properties of silicone-based isotropic adhesives has been the major difficulty to overcome and has essentially prevented commercialization. Another problem associated with silicones is that the addition polymerization reaction of silicones must be carefully controlled to prevent cure inhibition from various common chemical contaminants such as amines and sulfides. Other concerns include low-molecular-weight silicone polymer migration onto wirebond pads and very high GTE. There has been some activity in the development of hybrid resins that contain silicone blocks as comonomer with epoxies such that the epoxy processing can be maintained with the added stress reduction property of the silicones [52]. 

In anionic solution systems the feed stocks are typically dried over various types of dessicants because the systems are sensitive to water contamination. When using continuous anionic solution polymerization systems, it is necessary to employ low (ppm) concentrations of a chain-transfer agent in order to discourage gelation and fouling 1,2-butadiene is often used for this purpose in commercial applications. Alkyl-lithium-initiated polybutadiene is less prone to contain gel and does not contain the heavy metal catalyst residues associated with Ziegler-Natta catalyzed products. 

---