Rheological and thermal properties of saponified cassava starch‐g‐poly(acrylamide) superabsorbent polymers varying in grafting parameters and absorbency

Abstract

Cassava starch-graft-poly(acrylamide) superabsorbent polymers (SAPs) with varying absorbencies were synthesized. Weight average molecular weight (M w ) of the hydrolyzed starch-graft-copolymers ranged from 1.6 3 10 6 to 2.8 3 10 6 g/mol, the largest being shown by the sample with highest percentage grafting. The storage (G 0 ) and loss modulus (G 00 ) of hydrogels were determined as a function of frequency. G 00 was larger than G 0 for the hydrogels with higher absorbencies and exhibited a liquid-like behavior. However, hydrogels with lower absorbencies showed a reverse viscoelastic behavior. The viscosity of hydrogels determined using a Brookfield viscometer at different shear rates was found to be larger for the hydrogels with higher absorbencies. The melting temperature (T m ) and enthalpy change of fusion (DH f ) of the SAPs ranged from 149.7 to 177.7 C and 65 to 494.9 J/g, respectively and showed a positive correlation with grafting parameters and M w . Heavy metal ion removal capacity of hydrogel followed the order Cu 21 > Pb 21 > Zn 21 .

Classification, processing and application of hydrogels: A review

“…According to the authors, the main advantage is that the hydrogels may control the release of stored water as the soil dries, maintaining the soil humidity over a relatively long time. In addition, the presence Parvathy et al [105] studied the effects of hydrogels on the physical-chemical and biological properties of the soil, based on the saponified cassava starch-g-poly(acrylamide). They also investigated the effects of the same hydrogel on the growth parameters of chili (Capsicum annuum L.) in different irrigation intervals.…”

Superabsorbent hydrogels based on polysaccharides for application in agriculture as soil conditioner and nutrient carrier: A review

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Ecotoxicological Properties of Tulipalin A-Based Superabsorbents versus Conventional Superabsorbent Hydrogels

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