KAJIAN TENTANG KINERJA GRANULA LEMPUNG-KAPUR TERLAPIS HIDROGEL PVA-BORAT UNTUK KEPENTINGAN MATERIAL PERTANIAN - Luckyta Ramadhanty, - (2022)
ABSTRAK. Pada sektor pertanian, pupuk berperan sebagai pemenuh kebutuhan nutrisi tanaman. Penggunaan pupuk yang tidak terkontrol akan menimbulkan masalah pada tanaman dan lingkungan. Untuk mencegah permasalahan tersebut, maka digunakan Controlled Release Fertilizer (CRF) untuk meningkatkan efisiensi penyerapan nutrisi. Hidrogel digunakan sebagai pelapis CRF. Pada penelitian ini, hidrogel yang digunakan ialah hidrogel PVA-borat. Tujuan dari penelitian ini ialah untuk menentukan karakteristik hidrogel PVA-borat menggunakan FTIR; profil swelling ratio granula lempung-kapur-KCl berlapis hidrogel PVA-borat, profil water retention granula berlapis hidrogel PVA-borat; dan profil pelepasan KCl dari granula berlapis hidrogel PVA-borat ke dalam media aqua-DM. Pada penelitian ini dilakukan (1) karakterisasi hidrogel PVA-borat menggunakan FTIR; (2) sintesis granula lempung-kapur-KCl; (3) pelapisan granula dengan hidrogel PVA-borat dengan berbagai variasi jumlah pelapisan; (4) pengujian swelling ratio; (5) pengujian water retention; dan (6) pengujian release behavior. Granula terlapis hidrogel berwujud spheris, berwarna putih keabuan, tak berbau, keras dan kasar. Karakterisasi FTIR menunjukkan kemiripan spektrum PVA dengan PVA-borat dan terjadi pergeseran puncak O-H akibat penambahan crosslinker borat. Swelling ratio CRF meningkat seiring dengan meningkatnya jumlah pelapis, tetapi setelah 20 menit ada indikasi kerusakan pelapis; pelapisan hidrogel pada granula meningkatkan kemampuan granula dalam menahan air; dan profil pelepasan KCl dari granula lempung-kapur-KCl terlapis hidrogel PVA-borat menunjukkan kinetika orde 1 yang dapat diungkapkan dengan C(t)= C_0 (1-e^(-kt)) dengan k untuk TP = 0.01112442, P1 = 0.02181455, P2 = 0.03253546, P3 = 0.02726929, dan P4 = 0.02693599. ABSTRACT. In the agricultural sector, fertilizer plays a role as a provider of plants nutrient needs. Uncontrolled use of fertilizers will cause problems for plants and the environment. To prevent these problems, a Controlled Release Fertilizer (CRF) is used to increase the efficiency of nutrient absorption. Hydrogels are used as CRF coatings. In this study, the hydrogel used was PVA-borate hydrogel. The purpose of this study was to determine the characteristics of the PVA-borate hydrogel using FTIR; swelling ratio profile of clay-lime-KCl granules coated with PVA-borate hydrogel, water retention profile of PVA-borate hydrogel-coated granules; and KCl release profile from PVA-borate hydrogel-coated granules into aqua-DM medium. In this research, (1) characterization of PVA-borate hydrogel using FTIR; (2) synthesis of clay-lime-KCl granules; (3) coating of granules with PVA-borate hydrogel with various coating amounts; (4) swelling ratio testing; (5) water retention testing; and (6) testing release behavior. Hydrogel-coated granules are spherical in shape, grayish white in color, odorless, hard and coarse. The FTIR characterization showed the similarity of the PVA spectra with PVA-borate and there was a shift in the O-H peak due to the addition of a borate crosslinker. Swelling ratio of CRF increased with increasing number of coatings, but after 20 minutes there was an indication of coating damage; hydrogel coating on the granules increases the ability of the granules to retain water; and the release profile of KCl from clay-lime-KCl granules coated with PVA-borate hydrogel showed order 1 kinetics which could be expressed by C(t)= C_0 (1-e^(-kt)) with k for TP = 0.01112442, P1 = 0.02181455, P2 = 0.03253546, P3 = 0.02726929, and P4 = 0.02693599.