Development and characterization of arrowroot (Maranta arundinacea L.) fibre-reinforced thermoplastic starch biocomposites
Petroleum-based plastics are one of the most commonly used materials in the packaging industry, which has been a source of concern for the global environment. The increased production of harmful environmental plastic waste has fueled the development of natural-based, renewable, and biodegradab...
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| Main Author: | |
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| Format: | Thesis |
| Language: | English |
| Published: |
2022
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| Subjects: | |
| Online Access: | http://psasir.upm.edu.my/id/eprint/103761/1/FK%202022%2075%20UPMIR.pdf |
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| Summary: | Petroleum-based plastics are one of the most commonly used materials in the packaging
industry, which has been a source of concern for the global environment. The increased
production of harmful environmental plastic waste has fueled the development of
natural-based, renewable, and biodegradable materials. Therefore, environmental
sustainability and the absence of harmful carbon emissions during and after processing
are desirable characteristics of potential materials. Furthermore, the widespread
acceptance of natural fibres and biopolymers as green materials is being driven by the
rapid depletion of petroleum resources, as well as a growing awareness of global
environmental issues associated with the use of conventional plastics. Also, rising
petrochemical prices and environmental concerns are driving the development of natural
polymeric materials for a wide range of applications in food-packaging materials that are
more consumer-friendly. Among these materials, arrowroot (Maranta arundinacea L.)
has emerged as a vital and effective source of starch and fibres. Arrowroot belongs to the
Marantaceae family, which is typically found in tropical forests. When compared to other
agro-based products, arrowroot starch and fibres has some distinct advantages, including
lower cost than other natural sources and greater accessibility. Therefore, several
laboratory experiments were conducted to produce and characterize arrowroot fibres,
biopolymers, and biocomposite films. The samples were developed using a solution
casting method. Initially, arrowroot bagasse (ABF) and husk fibres (AHF) were extracted
and the physical, chemical, thermal, morphological properties, as well as crystallinity,
were characterized. The chemical composition analysis revealed that ABF has higher
cellulose (45.97 %) than AHF (37.35 %), cassava bagasse (10.04 %), and corn hull
(15.30 %). In addition, ABF is significantly low in lignin (2.78 %) and density (1.11
g/cm3
) than AHF, corn hull, and cassava. Concerning the above characterization of
fibres, it was found that the lignocellulosic biomasses from arrowroot are alternative
promising sustainable material, which can be used in food packaging as a renewable
filler. The second stage was designed to investigate the development of arrowroot starch (AS)
films using glycerol (G) as a plasticizer at the ratio of 15, 30, and 45% (w/w, starch basis)
to achieve a new biopolymer for the application of environmentally friendly materials.
The developed films were analysed in terms of physical, structural, mechanical, thermal,
environmental, and barrier properties. The incorporation of glycerol into AS film-making
solution reduced the brittleness and fragility of films. An increment in glycerol
concentration caused an increment in film thickness, moisture content, and solubility in
water, whereas density and water absorption were reduced. The tensile strength and
modulus of G-plasticized AS films were reduced significantly from 9.34 to 1.95 MPa
and 620.79 to 36.08 MPa, respectively, while elongation at break was enhanced from
2.41 to 57.33 %. FTIR analysis revealed that intermolecular hydrogen bonding occurred
between glycerol and AS in plasticized films compared to control films. The G-plasticized films showed higher thermal stability than control films. Water vapour
permeability (WVP) of plasticized films increased by an increase in glycerol
concentrations. Furthermore, a novel biodegradable thermoplastic arrowroot starch
(TPAS) film containing arrowroot fibre (AF) at different concentrations (0, 2, 4, 6, 8,
and 10 wt.%) was developed and characterized in terms of thermal, antibacterial activity,
water vapor permeability (WVP), biodegradability, physical, morphological (FESEM),
tensile and tear strength, and light transmittance properties. The TPAS/AF biocomposite
film revealed a higher degradation temperature (313.02 ℃) than other biocomposite
films, indicating better thermal stability. Furthermore, increasing AF concentration led
to a significant (p < 0.05) reduction in the linear burning rate and WVP of the
biocomposite films from 248.9 to 115.2 mm/min and 8.18 ×10-10 × g. s-1.m-1. Pa-1 to 5.20
×10-10 × g. s-1.m-1. Pa-1, respectively. The tensile and tear strengths of TPAS/AF
composites were increased significantly from 2.42 to 15.22 MPa and 0.83 to 1.28 MPa,
respectively, and the elongation was decreased from 46.62 to 6.21%. The findings
revealed that after being reinforced with fibres, the mechanical properties enhanced, and
the optimum filler content was 10%. Regardless of fibre loadings, the results of water
absorption testing revealed that the composite films immersed in seawater and rainwater
absorbed more water than distilled water. In addition, the incorporation of AF and control
film showed an insignificant effect against three pathogenic bacteria including
Staphylococcus aureus (ATCC 43300), Escherichia coli (ATCC 25922), and Bacillus
subtilis (B29). The soil burial findings demonstrated that the weight loss of TPAS/AF
biocomposite films was significantly higher than TPAS film. Overall, the reinforcement
of arrowroot fibre with TPAS film improves the properties of biocomposites for
environmentally friendly food packaging applications. The development of fully
biodegradable packaging films is essential in the continuous effort to address current
environmental issues and gradually replace commonly used conventional packaging materials. |
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