Biodegradable polymers water-soluble

GS Polymer Consultants, Chapel Hill, North Carolina 

More recently, in the last 25 years, it has become increasingly apparent that, in addition to the major commodity synthetic plastics, water-soluble commodity and specialty polymers and plastics, such as poly(acrylic acids), polyacrylamide, poly(vinyl alcohol), poly(aIkylene oxides), and even some modified natural polymers, for example, cellulosics and starch, may potentially contribute to environmental problems and should also be targets for biodegradable substitutes. 

Plastics and the Environment, Edited by Anthony L. Andrady. ISBN 0-471-09520-6 2003 John Wiley Sons, Inc. 

The chapter concludes with some projections for fumre directions for research and commercial opportunities for environmentally biodegradable water-soluble polymers. 

Degradable plastic, a plastic designed to undergo a significant change in its chemical structure under specific environmenfal conditions resulting in a loss of some properties as measured by standard test methods appropriate to the polymer 

---

Polyacrylic acid (PAA] is a biodegradable water-soluble polymer with a wide range of medicinal applications and is considered pharmaceutically safe. They are used for oral and mucosal contact applications in the form of controlled release tablets, oral suspensions, and bioadhesives. The unique property of PAA is that it exists as a liquid at pH 5 and as a gel at pH 7. Permeation of cations into the gelled polymer converts the gel back to a liquid. It is an ideal polymer used for ocular delivery of ribozymes to the corneal epithelium as a drug delivery vehicle. 

TEST METHODS FOR BIODEGRADABLE WATER-SOLUBLE POLYMERS... 

Hence, given the need for biodegradable water-soluble polymers to protect the environment and the ready availability of a disposal infrastructure in almost every country in the world, the opportunity is obvious and waiting a solution. 

SYNTHESIS OF BIODEGRADABLE WATER-SOLUBLE POLYMERS 505 Table 12.2 Photodegradation of Photo/Biodegradable Carboxylates... 

Miscellaneous recent acetal polymer chemistry to produce biodegradable water-soluble polymers includes superabsorbents [159], the use of hydroxycarboxylic acid to produce lubricants [160], scale inhibitors [161], and water-soluble packaging materials [162]. 

Although there has been much activity to produce totally biodegradable water-soluble polymers for a variety of applications, especially for detergents, few complete successes have been registered beyond poly(vinyl alcohol), poly(ethylene oxides), and poly(aspartic acids). Almost aU efforts to obtain carbon chain polymers that are completely biodegradable have failed, at least in the short-term testing protocols currently in use. Some promising leads are noted in condensation polymers, polyaspartic acids, and acetals and in the modihcation of natural polysaccharides. 

---