Sodium polyacrylate

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Sodium polyacrylate
Sodium polyacrylate skeletal.png
IUPAC name
Poly(sodium prop-2-enoate)
ECHA InfoCard 100.118.171
Molar mass Variable
Density 1.22 g/cm3
Safety data sheet MSDS
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Sodium polyacrylate, also known as waterlock, is a sodium salt of polyacrylic acid with the chemical formula [−CH2−CH(CO2Na)−]n and broad application in consumer products.[1] This superabsorbent polymer has the ability to absorb 100 to 1000 times its mass in water. Sodium polyacrylate is an anionic polyelectrolyte with negatively charged carboxylic groups in the main chain. While sodium neutralized polyacrylic acids are the most common form used in industry, there are also other salts available including potassium, lithium and ammonium.

The origins of superabsorbent polymer chemistry trace back to the early 1960s when the U.S. Department of Agriculture developed the first super absorbent polymer materials.[2]


Dyed sodium polyacrylate hydrogel beads

Sodium polyacrylate and other derivatives of polyacrylic acid have a wide variety of commercial and industrial uses. These include:

  • Animals
    • Pet pad[3]
    • Horse urine odor absorbing[4]
    • Drown-free water source for feeder insects[5]

Safety for humans[edit]

Acrylic acid

As a leftover of producing sodium polyacrylate, acrylic acid would cause a rash when contacts with skin. It should be less than 300 PPM as the absorbent material in paper diaper.[14]


  1. ^ "Water absorbing material – Sodium polyacrylate".
  2. ^ a b "History of Super Absorbent Polymer Chemistry". M2 Polymer Technologies, Inc. Retrieved 29 April 2009.
  3. ^ a b c "Superabsorbent polymer (SAP)". Howtor.
  4. ^ "Easy to Get Rid of Horse Manure / Urine Smell". Retrieved 2018-02-02.
  5. ^ a b c d e f g h i j k l m n "Sodium polyacrylate uses". Howtor.
  6. ^ "Chemical Name: Sodium Polyacrylate". Household Products Database. U.S. Department of Health and Human Services. August 2015. Retrieved August 29, 2016.
  7. ^ "What are the components of a typical disposable diaper?". Retrieved January 8, 2015.
  8. ^ "Sodium polyacrylate for diapers".
  9. ^ "Best way for industrial waste liquid management: Sodium Polyacrylate".
  10. ^ "Sodium polyacrylate – the absorbent material of Inflatable sandbags".
  11. ^ "Sodium polyacrylate in waterproof tape of cables".
  12. ^ Artificial Snow, M² Polymer Technologies, Inc., retrieved August 29, 2016
  13. ^ "Sodium Polyacrylate for Hot Cold Therapy Gel Pack".
  14. ^ "The Safety of sodium polyacrylate for human".