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PENGARUH PENAMBAHAN SELULOSA NANOKRISTAL DARI
KULIT ROTAN DENGAN
PLASTICIZER
GLISEROL DAN
CO-PLASTICIZER
ASAM ASETAT DALAM PEMBUATAN
BIOKOMPOSIT BERBAHAN DASAR PATI SAGU
(
Metroxylon sp)
ABSTRAK
Kulit rotan merupakan limbah yang dihasilkan dari industri pengolahan rotan yang memiliki kandungan selulosa sebesar 37,6%. Kandungan selulosa yang cukup tinggi membuat limbah kulit rotan berpotensi untuk digunakan sebagai bahan baku selulosa nanokristal (NCC) yang dimanfaatkan sebagai pengisi. Tujuan dari penelitian ini untuk mengetahui karakteristik selulosa nanokristal meliputi analisis TEM (Transmission Electron Microscope), XRD (X-Ray Diffraction) dan FTIR (Fourier Transform Infrared). Serta untuk mengetahui pengaruh penambahan selulosa nanokristal dari rotan dengan plasticizer gliserol dan co-plasticizer asam asetat terhadap karakteristik biokomposit pati sagu meliputi analisis biokomposit meliputi SEM (Scanning Electron Microscope), FTIR (Fourier Transform Infrared), densitas (density), kekuatan tarik (tensile strength), pemanjangan saat putus (elongation at break), dan penyerapan air (water uptake). Isolasi selulosa nanokristal menggunakan metode kimiawi dan mekanik dengan proses hidrolisis asam menggunakan asam sulfat 45% dan ultrasonikasi selama 10 menit dan dilanjutkan dengan proses filtrasi menggunakan membran dialisis. Pembuatan biokomposit menggunakan metode casting, dimana dilakukan penambahan bahan aditif pada matriks sagu dengan penambahan 1-4 wt% selulosa nanokristal (NCC) dari kulit rotan sebagai pengisi, 10-40 wt% asam asetat sebagai co-plasticizer dan 30 wt% gliserol sebagai plasticizer. Hasil analisis TEM (Transmission Electron Microscope) dan XRD (X-Ray Diffraction) selulosa nanokristal menunjukkan selulosa nanokristal memiliki diameter 10-100 nm dengan kristalinitas 84,46%. Hasil analisis FTIR (fourier transform infrared) menunjukkan bahwa hemiselulosa dan lignin telah berhasil dihilangkan. Hasil uji mekanik selanjutnya didukung oleh analisis SEM (Scanning Electron Microscopy) yang menunjukkan selulosa nanokristal (NCC) terdistribusi secara merata pada biokomposit dan analisis FTIR (Fourier Transform Infrared) biokomposit dengan penambahan selulosa nanokristal (NCC) dan asam asetat menghasilkan puncak serapan yang tajam dibandingkan dengan bioplastik. Hal ini menunjukkan bahwa selulosa nanokristal (NCC) dan asam asetat telah berhasil berikatan dengan gugus pati. Hasil analisis densitas (density) dan kuat tarik (tensile strength) terbaik adalah 0,26 gram/cm3 dan 2,84 MPa yang diperoleh pada penambahan selulosa nanokristal (NCC) 3% dan asam asetat 30%. Nilai terbaik dari pemanjangan saat putus (elongation at break) adalah 12,47% yang diperoleh pada penambahan selulosa nanokristal (NCC) 1% dan asam asetat 20%. Sedangkan dari uji penyerapan air (water uptake) yang terbaik adalah dengan penambahan selulosa nanokristal (NCC) 3% dan asam asetat 10% dengan nilai 9,37%.
Kata kunci : asam asetat, biokomposit, kulit rotan, selulosa nanokristal, pati sagu.
viii
THE EFFECT OF NANOCRYSTALLINE CELLULOSE FROM
RATTAN BIOMASS WITH GLYCEROL AS PLASTICIZER AND
ACETIC ACID AS CO-PLASTICIZER ADDITION
REINFORCED SAGO STARCH BIOCOMPOSITE
ABSTRACT
Rattan biomass is a fiber waste from processing industry of rattan which contains 37.6% cellulose. The high cellulose contents of rattan biomass make it a source of nanocrystalline cellulose as a filler in biocomposites. The aim of this research are to obtain the characterization of nanocrystalline cellulose each Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR). Also the effect of nanocrystalline cellulose from rattan biomass with glycerol as plasticizer and acetic acid as co-plasticizer addition on sago starch biocomposite. The characterization are Scanning Electron Microscope (SEM), Fourier Transform Infrared (FTIR), density, tensile strength, elongation at break, and water uptake. Isolation of nanocrystalline cellulose using chemical and mechanical methods by acid hydrolysis process using 45% sulfuric acid and ultrasonication for 10 minutes and followed by filtration process using dialysis membrane. Sago starch biocomposites were prepared using a solution casting method, which includes 1–4 wt% nanocrystalline cellulose from rattan biomass as fillers, 10-40 wt% acetic acid as co-plasticizer and 30 wt% glycerol as co-plasticizer. The results of Transmission Electron Microscope (TEM) and X-Ray Diffraction (XRD) characteristic of nanocrystalline cellulose show diameter of nanocrystalline cellulose was 10-100 nm with around shape and crystallinity 84.46%. Fourier Transform Infrared (FTIR) and chemical composition analysis demonstrated that lignin and hemicellulose structures were successfully removed. The results of mechanical properties were supported by Scanning Electron Microscopy (SEM) showed that nanocrystalline cellulose (NCC) was uniformly distributed / dispersed on the sago starch matrix and FTIR of biocomposite with nanocrystalline cellulose (NCC) and acetic acid addition resulted in a sharp peak absorption compared to bioplastics. This suggests that nanocrystalline cellulose (NCC) and acetic acid have been successfully binding to starch groups. The results showed the highest density and tensile strength values were 0.26 gram/cm3 and 2.89 MPa obtained at an additional of 3 wt% nanocrystalline cellulose (NCC) from rattan biomass and 30 wt% acetic acid. The best value of elongation at break was 12.47% obtained at 1 wt% nanocrystalline cellulose (NCC) and 20 wt% acetic acid addition. The lowest water absorption was 9.37% obtained at an additional of 3 wt% nanocrystalline cellulose from rattan biomass and 10 wt% acetic acid.
Keywords: biocomposite, biomass rattan, nanocrystalline cellulose, sago starch.
