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Cross-linker polymer��

Sodium polyacrylate

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As a non-toxic, harmless, nonpolluting polymer absorption material, sodium�polyacrylate is widely used in a variety of common products, from diapers to fake snow.

Sodium polyacrylate

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This polymer can absorb up to 800 times its own�weight in distilled water, 300 times in tap water and 60 times in 0.9% NaCl (a�standard solution to mimic urine absorbency).

The difference in these three solutions is the electrolyte concentration. This is due to the property of this polymer that increases osmotic pressure under low electrolyte concentrations, allowing the polymer to swell and decreases osmotic pressure under higher electrolyte concentrations causing release of water from the polymer. In deionized water, water is absorbed by the polymer to lower the [Na+] inside the polymer. When salt water is added to the gel, the electrolyte concentration outside of the polymer increases and water exits the polymer to equilibrate [Na+].

Sodium polyacrylate

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Applications of sodium polyacrylate

Cosmetic Uses: thickening agent
Agricultural Uses: Retain moisture
Baby and Feminine Products: Diapers
Medical Uses: surgical sponges
Fuel: Sodium polyacrylate is added to gas containers (jet fuel, diesel, and gasoline) to absorb water. It is used in filtration units that separate water from automobile and airplane fuel, increasing the efficiency of the vehicle.
Cables: Protects electrical and optical cables from moisture.

https://sciencing.com/commercial-uses-sodium-polyacrylate-6462516.html

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Ring polymer��

Sodium polyaspartate

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Sodium polyaspartate

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Sodium polyaspartate is a sodium salt of polyaspartic acid. It is biodegradable condensation polymer based on the amino acid aspartic acid.

This material can be synthesized in an environmentally friendly way and is biodegradeable, thus it is a green alternative to several materials such as sodium polyacrylate used in disposable diapers and agriculture.

In addition and due to its water-solubility and ability to chelate metal ions, polyaspartate is used as a biodegradeable anti-scaling agent and a corrosion inhibitor.

https://en.wikipedia.org/wiki/Sodium_polyaspartate

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Sodium polyaspartate

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The polymerization reaction is an example of a step-growth polymerization to a polyamide and in one practical procedure^[1] aspartic acid is simply heated to 180 °C resulting in water release and the formation of a poly(succinimide). In the subsequent step, this polymer is reacted with sodium hydroxide in water, which hydrolyzes one of the two amide bonds of the succinimide ring to form a sodium carboxylate. The remaining amide bond is thus the linkage between successive aspartate units. Each aspartate unit is identified as α or β according to which carbonyl of it is part of the polymer chain. The α form has one carbon in the backbone in addition to the carbonyl itself (and a two-carbon sidechain) whereas the β form has two carbons in the backbone in addition to the carbonyl itself (and a one-carbon sidechain). This reaction gives a sodium poly(aspartate) copolymer composed of approximately 30% α-linkages and 70% β-linkages.

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