Films toxic agent resistance

The most widely used epoxy systems are those which are based on pure epoxy resins, hardened with a curing agent. Curing of epoxy resins containing two epoxy groups per molecule can be readily accomplished by the addition of primary polyamines, such as ethylene diamine, diethylene triamine, triethylene tetramine, tetra-ethylene pentamine, etc. Aliphatic polyamines produce cured resins with the greatest chemical resistance. However, these systems have inadequate durability, weather resistance and film-forming properties. They are sensitive to humidity, errors in addition rates are quite possible, and the catalysts are relatively toxic. 

Polyethylene has excellent chemical resistance and is not attacked by acids, bases, or salts. (It is, however, attacked by strong oxidizing agents.) The other characteristics of polyethylene which have led to its widespread use are low cost, easy process ability, excellent electrical insnlation properties, toughness and flexibility even at low temperatures, freedom from odor and toxicity, reasonable clarity of thin films, and sufficiently low permeability to water vapor for many packaging, building, and agricultural applications. 

A recent review has discussed the many and varied chanical species that may be used as antimicrobial agents, of which silver has been much researched of late. This is because not only is it a non-toxic, broad spectrum antimicrobial, but it may be applied as a nanoparticulate form and so is easily introduced into fibres themselves instead of topically applied as finishes. However, there are concerns regarding its contribution towards microbial resistance. Of special interest to this review is the means of application and the fabric and garment issues which optimize the overall protective effectiveness. As already stated for silver, many agents may be introduced into the polymer melt or solution prior to extrusion into filaments (or films) and a number of these have been listed. A few currently available examples are ... 

Uses Anti-soil redeposition agent in laundry liq. and powds. shows surf. act. and can stabilize colloidal dispersions forms complexes with dyes and a variety of aromatic compds. forms hard, solv.-resist. films Properties Powd. sol. in water on neutralization (pH > 4.5 or higher) high m.w. Toxicology LD50 (oral) > 5000 mg/kg low toxicity, no skin/eye irritation Gaftex ACP1004 [ISP]... 

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