SINTESIS, KARAKTERISASI, DAN UJI PERFORMA HIDROGEL PVA/GA/POM/C SEBAGAI MATERIAL CRF DENGAN NUTRIEN UREA - Kanthi Pawening Tyas, - (2023)
ABSTRAK Control Release Fertilizer (CRF) digagas untuk meningkatkan efektivitas penggunaan pupuk. Dalam penelitian ini dikaji pembuatan, karakteristik, dan performa hidrogel sebagai agen CRF berbahan Polivinil Alkohol (PVA), Glutaraldehida (GA), Premna Oblongifolia Merr (POM) yang dimodifikasi dengan penambahan charcoal dan CNT. Hidrogel PVA/GA/POM dan PVA/GA/POM/CNT disintesis mengikuti prosedur penlitian seblumnya. Hidrogel PVA/GA/POM/C disintesis dalam beberapa variasi diantaranya PVA/GA/POM/C1, PVA/GA/POM/C3, PVA/GA/POM/C5, PVA/GA/POM/C7, dan PVA/GA/POM/C9. Optimasi komposisi PVA/GA/POM/C dilakukan dengan menguji swelling ratio dan water retention. Hasil optimasi menunjukkan komposisi hidrogel PVA/GA/POM/C1 memiliki kemampuan paling optimum. Hasil karakterisasi FTIR pada hidrogel PVA/GA/POM, PVA/GA/POM/CNT, dan PVA/GA/POM/C1 terdapat gugus O-H, C-H sp3, C=O, C-H sp2, dan C-O. Hasil XRD menunjukkan jarak interlayer PVA/GA/POM/CNT menurun dan PPG/GA/POM/C1 meningkat dari prekusor utama PVA/GA/POM. Hasil SEM menunjukkan PVA/GA/POM/CNT dan PVA/GA/POM/C1 tampak lebih kasar dari prekusor utama yaitu PVA/GA/POM. Hasil pengujian sudut kontak diperoleh hidrogel PVA/GA/POM/C1 lebih hidrofilik dari PVA/GA/POM dan PVA/GA/POM/CNT. Berdasarkan uji swelling ratio, hidrogel PVA/GA/POM/C1 lebih besar dari PVA/GA/POM dan berdekatan dengan PVA/GA/POM/CNT. Uji water retention menunjukkan PVA/GA/POM/C1 lebih rendah dari kemampuan hidrogel PVA/GA/POM dan PVA/GA/POM/CNT. Sementara itu, release urea dari dalam hidrogel PVA/GA/POM/C1 mengikuti bentuk kurva logistik (logistic curve) yang memenuhi ungkapan y=L/(1+e^(-k(x-x˳) ) ) dengan x0 bernilai 56,55144, k bernilai 0,04894463, dan L bernilai 0,6423674. Dari hasil percobaan disimpulkan bahwa hidrogel PVA/GA/POM/C1 dapat menjadi alternatif pengganti PVA/GA/POM/CNT. Kata kunci : charcoal, control release fertilizer, glutaraldehida, hidrogel, polivinil alkohol, POM, urea ABSTRACT Control Release Fertilizer (CRF) is initiated to increase the effectiveness of fertilizer use. In this research, the production, characteristics, and performance of hydrogels as a CRF agent made from Polyvinyl Alcohol (PVA), Glutaraldehyde (GA), Premna Oblongifolia Merr (POM) modified with the addition of charcoal and CNT were studied. PVA/GA/POM and PVA/GA/POM/CNT hydrogels were synthesized following previous research procedures. PVA/GA/POM/C hydrogels are synthesized in several variations including PVA/GA/POM/C1, PVA/GA/POM/C3, PVA/GA/POM/C5, PVA/GA/POM/C7, and PVA/GA/ POM/C9. Optimization of the PVA/GA/POM/C composition is carried out by testing the swelling ratio and water retention. The optimization results showed that the hydrogel composition with the addition of 1mL charcoal (PVA/GA/POM/C1) has the most optimum performance. The results of the FTIR characterization of the PVA/GA/POM, PVA/GA/POM/CNT, and PVA/GA/POM/C1 hydrogels contained O-H, C-H sp3, C=O, C-H sp2, and C-O groups. The XRD results showed that the PVA/GA/POM/CNT interlayer distance decreased and PPG/GA/POM/C1 increased from the main precursor PVA/GA/POM. The SEM results showed that PVA/GA/POM/CNT and PVA/GA/POM/C1 looked rougher than the main precursors, namely PVA/GA/POM. The results of the contact angle test showed that the PVA/GA/POM/C1 hydrogel is more hydrophilic than PVA/GA/POM and PVA/GA/POM/CNT. Based on the swelling ratio test, the PVA/GA/POM/C1 hydrogel is larger than PVA/GA/POM and adjacent to PVA/GA/POM/CNT. The water retention test showed that PVA/GA/POM/C1 is lower than the ability of PVA/GA/POM and PVA/GA/POM/CNT hydrogels. Meanwhile, the release of urea from the PVA/GA/POM/C1 hydrogel follows the shape of a logistics curve which satisfies the expression y=L/(1+e^(-k(x-x˳) ) ) with x0 being 56.55144 , k is 0.04894463, and L is 0.6423674. From the experimental results it is concluded that PVA/GA/POM/C1 hydrogel could be an alternative to PVA/GA/POM/CNT. Keywords : charcoal, control release fertilizer, glutaraldehyde, hydrogel, polyvinyl alcohol, POM, urea