PolyAcrylic Acid

1. POLYACRYLIC ACID (PAA)
Polymer Technology
By: Kudzai Hamish Ruzvidzo
B Tech (Chemical Process Systems Engineering)
M Tech (Polymer Science and Technology)
vakudzaihamish@gmail.com

2. Introduction
• Polyacrylic acid (PAA) is a polymer made from the monomer acrylic acid.
• These long chains contain thousands of monomer units, and the polymer
also has some cross-linking between the chains.
• Many polymers, such as polyethylene and polystyrene (used in trash bags,
plastic bottles, and Styrofoam®, for example) are hydrophobic, meaning
they repel water.
• Polyacrylic acid, however, is very hydrophilic - it attracts water. That's
because of the carboxylic acid groups (COOH) in the polymer, which can
hydrogen-bond to water molecules.
• Thus PAA is a super-absorbent polymer

3. Monomer
• Polyacrylic acid is made from the monomer acrylic acid
• Acrylic acid (IUPAC: prop-2-enoic acid) is an organic compound with
the formula CH2=CHCOOH.
• It is the simplest unsaturated carboxylic acid, consisting of a vinyl
group connected directly to a carboxylic acid terminus.
• This colorless liquid has a characteristic acrid or tart smell.
• It is miscible with water, alcohols, ethers, and chloroform.

4. Synthesis by Free Radical Mechanism

5. Synthesis by anionic polymerization

6. Properties
• Hygroscopic, brittle and colorless in nature
• In a water solution at neutral pH, PAA is an anionic polymer, i.e. many
of the side chains of PAA will lose their protons and acquire a negative
charge.
• This makes PAAs polyelectrolytes, with the ability to absorb and retain
water and swell to many times their original volume.
• Tg at nearly 106oC
• At temperatures above 200 to 250oC, it loses water and becomes an
insoluble crosslinked polymer anhydride.
• Solubility of dried PAA in water increases with rise in temperatures.
• Concentrated solutions of PAA in water is thixotropic in nature.

7. Applications

8. • Disposable diapers
• Hand sanitizer
• Ion exchange resins
• Mascara
• Aftershave
• Toothpaste
• Hair-styling products (gels, dyes, sprays)
• Moisturizer
• Pet shampoo
• Metal polish
• Thickening, dispersing, suspending and emulsifying agents in cosmetics,
pharmaceuticals and paints
• May inactivate the antiseptic chlorhexidine gluconate

9. Did you know??
• Polyacrylic acid is developed by ReProtect.
• It is a gel that may help both block the spread of sexually transmitted
diseases and reduce unwanted pregnancies.
• The compound, known as BufferGel, is currently in advanced clinical
trials for its ability to prevent pregnancy.
• Source: DrugBank
Record Name: polyacrylic acid
URL: http://www.drugbank.ca/drugs/DB05384