Polyethylene oxide , acid-degradable

Formaldehyde, along with other short-chain aldehydes such as acetaldehyde, is a low molecular weight, volatile, reactive contaminant that can be present at low levels from a variety of sources (e.g., excipients such as polyethylene oxide, polyethylene glycol (64,65), or from carbohydrate degradation (66), solvent contamination (51), packaging materials (52), etc.). Formaldehyde is known to react with amines (Fig. 33) to form a reactive N-hydroxymethyl compound (a hemiaminal) that can further react with other nucleophiles. Reaction of formaldehyde with amino acids (67) can cause... 

Figure 9. The effect of untreated and oxidized polyethylene on ascorbic acid degradation in a model solution, stored at 35°C.

OBPs based on a full-aliphatic-carbon backbone such as polyethylene (PE) and polypropylene (PP), when doped with relatively small amounts of pro-oxidant/pro-degradant additives (0.5-1 % by weight of fatty acid salts of transition metals such as Fe, Mn, or Co or their combination), become susceptible to an oxo-biodegradation process occurring at the end of their predetermined service life. 

The use of additives in aqueous emulsions for mist suppression has been only recently been explored (1,2,3). In particular, high molecular wei t polyethylene oxide EO) polymers have received considerable testing and have shown to have some degree of success in reducing mist. However, these polymers have a finite lifetime in the fluid before they shear degrade. Thus, this has led to the development of novel shear stable polymers derived from a highly hydrophilic sodium-2-acrylamido-2-methyl propane sulfonic acid (NaAMPS) monomer polymerized with hydrophobic monomers. (4)... 

Hypalon is a tradename for CSM chlorosulfonated polyethylene. It offers good resistance to moderate chemicals, ozone, alkaline solutions, hydrogen. Freon, alcohols, aliphatic hydrocarbons, as well as ultraviolet degradation from sunrays. Strong oxidizing acids, ketones, esters, acetic acid, and chlorinated and nitro-hydrocarbons attack Hypalon. Its temperature range for applications is from -40°C to 150°C (-40°F to 300°F). Its physical properties are presented in Table 10-16. 

---