PRELIMINARY STUDY ON POTENTIAL USE OF PVA/GA/POM/C HYDROGEL FOR BINDER COMPONENT ON SLOW/CONTROLLED-RELEASE FERTILIZER Hendrawan Hendrawan, Diah Indriati, Kanthi Pawening Tyas, Hafiz Aji Aziz
Universitas Pendidikan Indonesia
Abstract
In previous study, it had been shown that introduction of dispersed carbon nanotube (CNT) into hydrogel made from poly(vinyl alcohol) (PVA), glutaraldehyde (GA), and Premna Oblongifolia Merr. (POM) - denoted as PVA/GA/POM/CNT - can increase its agrochemical performance in term of Slow/Controlled-release fertilizers (S/CRFs) parameters. For practical consideration, dispersed charcoal (C) - which is also carbon-based material - was selected as replacement of CNT. This study is performed in 2 phases, which are (1) synthesis of hydrogel based on combination of PVA, GA, POM and C- and (2) investigation of the physicochemical properties and agrochemical performance of the hydrogel. The hydrogel synthesized include PVA/GA/POM, PVA/GA/POM/CNT, and PVA/GA/POM/Cx (x = 1, 3, 5, 7, 9). The physicochemical properties tested was the hydrophilicity aspects, while the agrochemical parameters tested were swelling ratio (SR), water retention (WR), and desorption of nutrient from hydrogel. This study shows that PVA/GA/POM/C1 exhibit comparable performance to PVA/GA/POM/CNT in term of SR and WR. Even though PVA/GA/POM is less hydrophilic compared to PVA/GA/POM/CNT and PVA/GA/POM/C1, there was indication that it is more easily ruptured in SR testing. Equilibrium condition of KCl release process into aqua-dm from PVA/GA/POM/C1 was reached more rapidly than that from PVA/GA/POM/CNT. On the other hand, release of KCl from PVA/GA/POM and PVA/GA/POM/C1 reached equilibrium within comparable time, however PVA/GA/POM was able to desorb more KCl.
