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The Effect of Nanocrystalline Cellulose from Rattan Biomass with
Glycerol as Plasticizer and Citric Acid as Co-Plasticizer Addition
Reinforced Sago Starch Biocomposite
ABSTRACT
Rattan biomass is the one bioresources of cellulose which contains 37,6% cellulose content. The high cellulose contents of biomass rattan make it a source of nanocrystalline cellulose as a filler in biocomposite. 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). And this research studied about the effect of filler loading of nanocrystalline cellulose from biomass rattan, plasticizer glicerol and co-plasticizer citric acid 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 from biomass rattan using chemical and mechanical method by acid hydrolysis process with sulfuric acid 45%, ultrasonication for 10 minutes, and filtration with 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% citric acid as co-plasticizer and 30 wt% glycerol as 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 84.46% of crystallinity index. 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 on the sago starch matrix and FTIR of biocomposite with nanocrystalline cellulose (NCC) and citric acid addition resulted in a sharp peak absorption compared to bioplastics. This suggests that nanocrystalline cellulose (NCC) and citric acid have been successfully binding to starch groups. The results showed the highest density and tensile strength values were 0.28 gram/cm3 and 1,76 MPa obtained at an additional of 3 wt% nanocrystalline cellulose (NCC) and 30 wt% citric acid. The best value of elongation at break was 32,48% obtained at 1 wt% nanocrystalline cellulose (NCC) and 30 wt% citric acid addition. The lowest water absorption was 14,81% obtained at an additional of 3 wt% nanocrystalline cellulose from rattan biomass and 10 wt% citric acid.
Keywords: biocomposite, biomass rattan, citric acid, nanocrystalline cellulose, sago starch.
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Pengaruh Penambahan Selulosa Nanokristal Dari Kulit Rotan
Dengan
Plasticizer
Gliserol Dan
Co-Plasticizer
Asam Sitrat Dalam
Pembuatan Biokomposit Berbahan Dasar Pati Sagu
(
metroxylon sp)
ABSTRAK
Selulosa merupakan sumber daya alami yang melimpah, salah satu sumber selulosa adalah kulit rotan yang mengandung 37,6% selulosa, sehingga berpotensi untuk digunakan sebagai bahan baku selulosa nanokristal (NCC) yang dimanfaatkan sebagai pengisi dalam pembuatan biokomposit. Tujuan dari penelitian ini adalah 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 kulit rotan dengan plasticizer gliserol dan co-plasticizer asam sitrat terhadap karakteristik biokomposit pati sagu meliputi analisis 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 ke dalam matriks pati sagu dengan penambahan 1-4 wt% selulosa nanokristal kulit rotan sebagai pengisi, 10-40 wt% asam sitrat 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 sitrat menghasilkan puncak serapan yang tajam dibandingkan dengan bioplastik. Hal ini menunjukkan bahwa selulosa nanokristal (NCC) dan asam sitrat telah berhasil berikatan dengan gugus pati. Hasil analisis densitas (density) dan kuat tarik (tensile strength) terbaik adalah 0,28 gram/cm3 dan
1,76 MPa yang diperoleh pada penambahan selulosa nanokristal (NCC) 3% dan asam sitrat 30%. Nilai terbaik dari pemanjangan saat putus (elongation at break) dan penyerapan air (water uptake) adalah 32,48% dan 14,81% yang diperoleh pada penambahan 1% selulosa nanokristal (NCC) dan 30% asam sitrat.
Kata kunci : asam sitrat, biokomposit, kulit rotan, selulosa nanokristal, pati sagu.
