Pengayaan Superabsorben Onggok-Poliakrilamida Melalui Pencampuran Superabsorben dengan Urea-Pati

Abstract

Onggok-based superabsorbent polymer (SAP) was synthesized with optimized grafting-crosslinking method by using ammonium peroxydisulphate as initiator, acrylamide (AAm) as monomer, and N,N'-methylene bis-acrylamide as crosslinker. SAP was saponified with 1 M NaOH to increase its water absorption capacity. SAP enrichment was conducted by mixing urea-starch with SAP physically with varied composition, 2:1, 3:1, and 4:1. The success of SAP synthesis and saponification were confirmed by Fourier transform infrared spectra, which showed all characteristic bands of onggok, AAm, and carboxyl anion, as well as the increase of SAP’s water absorption. All of urea-enriched SAP were applied in static water media with various time interval to study the best urea leaching pattern. SAP mixture with 3:1 ratio gave the best leaching pattern with optimum leaching time was 4 days, nitrogen release was 41.13% (42.6187 ppm), and release rate of urea was 0.8893 ppm/minute.

Polimer superabsorben (SAP) berbahan dasar onggok disintesis dengan metode pencangkokan-penautan-silang yang telah dioptimasi menggunakan inisiator amonium persulfat, monomer akrilamida (Aam), dan penaut-silang N,N’- metilena bis-akrilamida. SAP disaponifikasi dengan NaOH 1 M untuk meningkatkan daya serapnya terhadap air. Pengayaan SAP dilakukan dengan mencampurkan urea-pati dengan SAP secara fisik dengan variasi komposisi 2:1, 3:1, dan 4:1. Keberhasilan sintesis dan saponifikasi SAP ditunjukkan oleh pita serapan khas onggok, Aam, dan anion karboksilat pada spektrum inframerah transformasi Fourier serta peningkatan daya serap SAP. Seluruh SAP yang telah diperkaya urea diaplikasikan dalam media air statis dengan selang waktu tertentu untuk melihat pola pelepasan urea terbaik. Campuran SAP dengan nisbah 2:1 memberikan pola pelepasan terbaik dengan waktu pelepasan optimum 4 hari, pelepasan nitrogen sebesar 41.13% (42.6187 ppm), dan laju pelepasan urea sebesar 0.8893 ppm/menit.