ARTICLE REVIEW
Wan Aizan Wan Abdul Rahman; Roshafima Rasit Ali; Wan Hasamudin Wan Hasan and Izzati Nazreen Muhammad Tajudin, “Biocomposites based on oil palm tree as
packaging material” (2007), http://eprints.utm.my/5735/
NOTE This powerpoint review is made by Masni-Azian Akiah as part of the data management of her project. Refer full article for complete report. Full credit to respective author(s).
GIST OF ARTICLE
• Utilization of oil palm empty fruit bunch (EFB) fibre waste for packaging industry (focusing on plastic film with blow film processing)
• Incorporate use of palm cooking oil (PCO) to improve processing efficiency.
JUSTIFICATION TO STUDY
• Environmental awareness
• Utilise of local natural resource
• Improve blow film process difficulties of EFB based material.
BACKGROUND
• Increasing environmental awareness to biodegradable packaging.
Biodegradable : * can be decomposed in soil * may act as fertiliser and soil conditioner. * facilitates better yield and crops
• Amount of oil palm EFB waste generated generated by palm oil industry in Malaysia ~ 8 million tons per year -> utilise natural resources
BACKGROUND
• Characteristics of good packaging films: Good oxygen barrier
Prevent microbial spoilage during extended storage
Good tensile strength
Able to maintain structural integrity
BACKGROUND
• Oil palm empty fruit bunch (OPEFB) Cellulose (majority)
Hemicellulose
Lignin
• Packaging film Combination of OPEFB + PE = semibiodegradable
Easily processed on conventional thermoplastic extrusion blow film machine.
ADVANTAGE: • Lower density • Greater deformability • Lower cost per unit volume
BACKGROUND
• Difficulties to current biopolymer processing Not easy with increasing biodegradable material
Resistance to flow is increased in the extruder.
• Solution to difficulties addition of lubricant oil (Ref : R.N. Taranathan, 2003)
Use of vegetable oil
• Plasticizer that improve film quality
• Pro-oxidant to accelerate film degradation
EXPERIMENTAL METHOD
• MATERIAL Matrix : LDPE (Titanlane) • Supplier : Titan Polyethylene (M) Bhd. • Grade : 260 for blow film process • Melt flow index (MFI=5.05g/10min) • Density : 0.8498 𝑔/𝑐𝑚3
Filler : Oil palm EFB fibre • Supplier : Malaysian Palm Oil Bhd. (MPOB) • Ave. fibre length : 610 m
Lubricant : palm cooking oil (PCO) • Supplier : Malaysian Palm Oil Bhd. (MPOB) • Major composition : Gleycerids & fatty acid
EXPERIMENTAL METHOD
• COMPOSITE (LDPE/EFB/PCO) EFB = 5%
PCO = 1%, 2%, 5%, 10%
• MELT FLOW INDEX (MFI) ASTM D1238-01
Load : 2.16 kg
Temperature : 190C
EXPERIMENTAL METHOD
• EQUIPMENT Lloyd Tensile Machine
• Tensile strength, elastic modulus, and elongation at break.
• Film specimen : ASTM D638 – Type V
• Crosshead speed : 10 mm/min
• Sample size : 6
Differential Scanning Calorimetry (Perkin Elmer DSC 7)
• To study thermal properties of films
• Sample weight : 4~6 gm
• Heating temp : 40 220C (rate of 20C per min)
RESULTS (addition of EFB)
• Melt flow index (MFI) decreases Low MFI : high resistance to flow in extruder
Why? No bubble expansion occurred during processing
EFB addition hindered film forming, but can still be processed via compression moulding & thermoforming.
MATERIAL WEIGHT % MFI VALUE (g/10min)
LDPE 100 5.05
LDPE / EFB5 95/5 4.2
RESULTS (addition of EFB)
• Tensile strength lowers Why? Poor EFB fibre to LDPE matrix interaction/compatibility.
• Elongation lowers Why? Incompatability of EFB-LDPE
• Melting temperature (Tm) unchanged Unchanged degree of crystallization
PROPERTIES LDPE LDPE/EFB
Tensile strength (MPa) 9.30 9.10
Elongation at break (%) 125 45
Tm (C) 107.51 107.49
RESULTS (addition of PCO)
• Melt flow index (MFI) increases WHY? Viscosity decreases with addition of PCO, thus, process ability can be improved.
But, still cannot process at weight % 94/1/5 * extruded bubble is not able to expand fully * WHY? poor fibre-matrix interaction.
Increasing more PCO, OK. * extruded bubble are able to expand.
RESULTS (addition of PCO)
• Tensile strength decreases Lubricant decreases intermolecular forces between polymer chains to slide past one another.
Irregular shape of EFB fillers poor capability to support stress transmitted from thermoplastic matrix
EFB maintains its rigid filler shape during processing filler distribution is not achieved, less interfacial EFB-LDPE region
• Elongation at break decreases As above
RESULTS (addition of PCO)
• Melting temperature (Tm) decreases Improved EFB-LDPE interaction due to lubricant presence
Lubricant act as plasticiser LDPE chain becomes more flexible, easy to move and rotate reduction to degree of crystallinaty
CONCLUSION
• PROCESSABILITY (on conventional blow film thermoplastic machinery)
lubricant , better LDPE/EFB processability, flow resistance. Lubricant > 2%, can process LDPE/EFB/PCO into film.
• TENSILE PROPERTIES
lubricant, tensile strength
• ELONGATION AT BREAK lubricant, elongation at break (weaker)
• MELTING TEMPERATURE lubricant, Tm