Starch and itaconic acid-based superabsorbent hydrogels for agricultural application

Biobased superabsorbent is considered as an interesting polymeric material with excellent water absorption capacity. It can act as an active agent carrier and soil conditioner along with others. Howsoever, extensive usage of polymeric superabsorbent derived from conventional petroleum sources is posing serious threats to sustainability of the ecosystem. In this facet, a high biobased content (63 %) superabsorbent was synthesized using starch and itaconic acid as renewable resources. The prepared superabsorbent polymer was authenticated by its high-water absorption capacity (650 g/g) due to the presence of porous morphology as supported by SEM image analysis and the presence of various polar groups in its structure as confirmed by Fourier transform infrared (FTIR) spectral analysis. The superabsorbent hydrogels with different compositions were prepared and their performance was evaluated towards water absorption with and without load, and in salt solutions. The swelling kinetic studies of the hydrogels revealed faster water absorption with higher itaconic acid content. The urea encapsulated hydrogels were used in soil to judge their abilities for water holding capacity, seed germination rate, soil porosity enhancement, etc. Moreover, the hydrogels possess good biodegradability as confirmed by the soil burial study, and thereby endowing the environmentally benign characteristic which can overcome the shortcomings of petroleum-based hydrogels. Thus, they have great potential to be used in agricultural applications, especially as environmentally friendly superabsorbent.