E.S.Iriani1, F. Fahma2 and T.C. Sunarti2 PHYSICAL AND MECHANICAL PROPERTIES OF PVA NANOCOMPOSITE REINFORCED WITH SORGHUM BAGASSE NANOCELLULOSE E.S.Iriani1, F. Fahma2 and T.C. Sunarti2 1Indonesian Center for Agricultural Postharvest Research and Development. Ministry of Agriculture 2Bogor Agricultural University

Background Our dependency on plastic almost 100 million tones/year Indonesia plastic consumption near $ 2 billion/ year Plastics : Light and strong Flexible Transparent Water resistant Cheap

Negative impact of plastic Non biodegradable Source : oil  non renewable Incineration  dioxin  Carcinogenic Mygration  Hormonal, Reproduction, etc

ALTERNATIVE SOURCES FOR BIODEGRADABLE PACKAGING Renewable Biodegradable Safe for environment and health Easy to process Agrowaste

Low mechanical properties Biodegradable Polymer Limitation Expensive Hidrophylic Brittle High permeability Low mechanical properties Fiber Reinforcement

CELLULOSE  Fiber Reinforcement Renewable Abundant Low density High modulus Biodegradable High compatible Minimum energy requirement

WHY NANO CELLULOSE High variability in diameter and length of cellulose  improper dispersion  reduce their performance Reducing size of cellulose to nano  improve dispersion on matrix polymer Nanocellulose  high surface area, high aspect rasio, good optical properties Nanocellulose have the ability to create entangled networks  improve mechanical properties Nanocellulose (nanocrystal)  improve barrier properties and also thermal properties

Nano Cellulose Preparation Mechanical Homogenization Microfluidizer Supermasscoloider Cryocrushing Sonication Chemical Oxidator Agent (TEMPO) Acid hydrolysis

Polyvinyl Alcohol Synthetic polymer from crude oil that can dissolve by water Can perform good coating film layer  high tensile strength and flexibility High compatibility with nanocellulose (Roohani et al., 2008) Non toxic, highly crystalline, high hydrophilic properties (Ibrahim et al., 2010)

METHODOLOGY

Materials and Instruments Materials : agrowaste (sorghum bagasse), PVA, NaClO2,KOH, H2SO4, HCl, chemical for analysis Instruments : Supermasscolloider, Ultraturax, Ultrasonicator, TEM, SEM, PSA, DSC, XRD, UTM

Soaking 6x in acid condition 37.5 gr NaClO2 + 5 ml CH3COOH Screening Soaking 6x in acid condition (@ t = 1 hour; T = 70oC) Lignin Rinse KOH 6% (w/w) Sorghum Bagasse Cellulose Hemi cellulose Neutralizing  pH 7 Bleaching (T = 300 C; t = 24 hour) Cellulose

Nanocellulose Production by Supermasscolloider 1% cellulose  10 cycle gap 0;10 cycle gap -5; 10 cycle gap -10

3. BIOCOMPOSITE PVA-NANOCELLULOSE PRODUCTION Nanofiber ( 1-5%) Glycerol (0%, 2%) PVA Solution (10%) COMPOSITE SOLUTION + = + Pencampuran Biocomposite Film PVA-Nanocellulose Drying (T = 40oC; t = 2 hr) Casting

Nanocomposite Characterization Physical properties Color by Chromameter Density Crystalinity by XRD Mechanical properties by UTM Tensile Elongation Structure Morphology by TEM and SEM

RESULTS AND DISCUSSION Cellulose Isolation Table 1. Sweet Sorghum Bagasse Composition Component Before Isolation After isolation Lignin (%) 20,72 3.09 Hemicellulose (%) 25,91 1.24 Cellulose (%) 41,10 89.57

PHYSICAL PROPERTIES OF PVA-NS COMPOSITE Addition of NS  Increase density Increasing NS  increase density Addition of plastisizer  increase density

Crystalinity of PVA-NS Composite Addition of NS  increase crystallinity of composite Increasing NS  increase crystallinity Addition of plastisizer  decrease the crystallinity

BIOCOMPOSITE PVA-NANOCELLULOSE FILM TRANSPARANCY

STRUCTURE MORPHOLOGY OF SORGHUM BAGASSE CELLULOSE 500 X 20 X

STRUCTURE MORPHOLOGY OF NANOCELLULOSE TEM Results of Sorghum Nanocellulose

ELONGATION OF PVA-NS COMPOSITES Increasing NS up to 4% wo plastisizer  Increase elongation of composites Plastisizer addition  decrease elongation of composites Antiplastisizer Effect due to low concentration < 10%

Tensile Strength of PVA-Nanocellulose Increasing NS  decrease tensile strength Addition plastisizer  decrease tensile strength Elongation decrease due to : Inadequate wetting of the fibre with the matrix Poor adhesion between the filler and matrix Uneven aligning of the nanofiber

PVA-Nanocellulose Permeability (WVTR) Increasing NS up to 4%  decrease WVTR Plastiisizer addition  increase WVTR There were some voids due to poor adhesion and poor dispersion

Cross Section Morphology by SEM Increasing NS up to 50% gave porous structure  indicating disperse of NS with PVA forming holes  decrease tensile strength

CONCLUSION Addition of Sodium chlorite with reflux 6 cycle can eliminate other materials such as lignin and hemicellulose to obtain cellulose content near to 90%. Supermass colloider  Nano fibrillated cellulose (Diameter < 100 nm) Nanocellulose addition  Improve mechanical properties (elongation) and decrease permeability  Potential for fiber reinforcement Glycerol addition  Decrease tensile and increase permeability. Most probably due to antiplastization effect : too low concentration of plastisizer

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