Therefore, the nanocomposite fibers from rice straw can be
used to increase the resistance of nanocomposites, when
unified in polymeric matrices because of their high aspect
ratio, which is associated with structures interconnection
abilities (Riva et al. 2018).
Rice straw is a material rich in cellulose (around 47%),
hemicellulose (approximately 27%), and lignin (below 24%)
(Mohammad et al. 2018; Garrote et al. 2002). It is the main
feedstock for ethanol production Saha (2003). From the rice
crop, 1.5 kg of straw can be generated from each 1 kg
harvested biomass. However, in several countries, rice straw
is usually burnt or discarded in rivers and lakes, contaminating and polluting air, water, and soil Binod et al. (2010).
Nowadays, many agricultural byproducts and other inedible
food residues, e.g., potato peels, sugarcane bagasse, shrimp
husks, eggshell, and lignocellulosic fibers are used to produce ecofriendly materials (Sangon et al. 2018; Tiimob et al.
2017; Chiellini et al. 2001). Rice straw residues can be easily
handled as they do not require separation from other residues
(Moro et al. 2017).
There are numerous bioplastic applications from food
packaging to medical care. Food packaging is a significant
material (Dominguez-Escriba and Porcar 2010), it must be
resistant to contact with oils and water. Bioplastics have the
function of protecting food from exposure to the ambient
and ensuring its quality and durability (Gilbert et al. 2017).
Despite the improvements achieved in research, there are
still some challenges to be overcome. Properties, such as
thermal variability, water vapor, fragility, and resistance to
melting must be optimized. The difficulties previously
mentioned have encouraged research on bioplastic functionality improvements. The use of cellulose, nanoparticles,
and chemical modifications are some of the mechanisms
employed to reduce the limitations of bioplastics (Siracusa
et al. 2008; Sartore et al. 2015). On the other hand, to create
a low-cost bioplastic with mechanical characteristics same as
those of synthetic plastic materials, e.g., polyethylene and
polypropylene is very difficult.
From rice straw, bioplastics rich in cellulose can be
produced. After pretreatment with trifluoroacetic acid (TFA),
the cellulose present in the rice straw is extracted to produce
bioplastic (Sartore et al. 2016). TFA is an organic acid
solvent for cellulose (Bayer et al. 2014). Furthermore, it can
be simply recycled via distillation and added to other organic
solvents, for example, water.
4.2 Soy Protein Bioplastics Applied
to Commercial Polyethylene
Artificial plastics produced from petroleum have several
beneficial properties, e.g., in cost terms, ease of processing,
and mechanical strength, and are produced globally in large
quantities (Zhao et al. 2007). These artificial plastics have
applications for several types of products, such as industrial
components and throw away materials. However, as plastics
are primarily derived from petroleum, due to the overuse of
this resource, carbon dioxide, and other toxic compounds are
released into environment during production, and this is a
major problem.
In addition, synthetics plastics, such as polyethylene,
polypropylene, and polyvinyl chloride present low degradability in environment and may remain for hundreds of years
(Emadian et al. 2017; Thompson et al. 2009; Hester and
Harrison 2018). Plastic waste polluting the ocean is also a
major global contamination problem (Thompson et al. 2009;
Luckachan and Pillai 2011). Therefore, an alternative to
using plastic is the artificial plastic or bioplastic, which is
composed of natural biopolymers (Thompson et al. 2009;
Hester and Harrison 2018). Bioplastics are biopolymers
produced from renewable biomass sources, such as wood,
natural rubber, carbohydrates, food waste, and proteins (Pico
and Barcelo 2019; Xu et al. 2019; Lambert and Wagner
2017). In addition, biopolymers are easily obtained from
nature, so there are no costs compared to synthetic polymers.
Biopolymers are not dangerous to humans and are ecofriendly materials. Therefore, bioplastics composed of
biopolymers, for example, starch Brodin et al. (2017),
agarose Sagnelli et al. (2016), casein Awadhiya et al. (2016),
lignin Sutermeister and Browne (1939), and keratin Kai et al.
(2016) are great alternatives to synthetic plastic.
Soybean is one of the more cultivated plants in the world,
especially in East Asia, where it is consumed as tofu (unfermented food), but also as miso and soy sauce (fermented
food). However, soybeans contain good fat (20%) and protein (35%) contents (Ramakrishnan et al. 2018; El-Shemy
2013). Therefore, soybeans are used worldwide for oil.
Ungreased soybeans contain many proteins. The residues of
ungreased soybeans are largely discarded, even though they
are used for human and as animal feed (Ramakrishnan et al.
2018). Degreased soybeans have been utilized to prepare
cellulosic materials (Visakh and Nazarenko 1998), glycerol
(Paetau et al. 1994), polyacrylamide (Tian et al. 2012), and
graphene (Xu et al. 2015). However, the treatments applied
to produce the cellulosic material from degreased soybean
are complex. Therefore, to green chemistry to prepare bioplastics by a simple process is an ideal way to minimize
contamination.
Soybean protein is basically composed of lysine and
arginine, neutral amino acids, such as glycine, valine, alanine, and leucine, and also aspartic and glutamic amino acids
(Jiang et al. 2016). The carboxyl or amino acid groups in the
residues are modifiable functional groups. In particular,
under moderate conditions, formaldehyde reacts with amino
groups to produce methylol, and forming a methylene
cross-link, e.g., N-CH 2 -N (Yamada et al. 2020; Taira 1973;
290
A. A. Santana et al.
used to increase the resistance of nanocomposites, when
unified in polymeric matrices because of their high aspect
ratio, which is associated with structures interconnection
abilities (Riva et al. 2018).
Rice straw is a material rich in cellulose (around 47%),
hemicellulose (approximately 27%), and lignin (below 24%)
(Mohammad et al. 2018; Garrote et al. 2002). It is the main
feedstock for ethanol production Saha (2003). From the rice
crop, 1.5 kg of straw can be generated from each 1 kg
harvested biomass. However, in several countries, rice straw
is usually burnt or discarded in rivers and lakes, contaminating and polluting air, water, and soil Binod et al. (2010).
Nowadays, many agricultural byproducts and other inedible
food residues, e.g., potato peels, sugarcane bagasse, shrimp
husks, eggshell, and lignocellulosic fibers are used to produce ecofriendly materials (Sangon et al. 2018; Tiimob et al.
2017; Chiellini et al. 2001). Rice straw residues can be easily
handled as they do not require separation from other residues
(Moro et al. 2017).
There are numerous bioplastic applications from food
packaging to medical care. Food packaging is a significant
material (Dominguez-Escriba and Porcar 2010), it must be
resistant to contact with oils and water. Bioplastics have the
function of protecting food from exposure to the ambient
and ensuring its quality and durability (Gilbert et al. 2017).
Despite the improvements achieved in research, there are
still some challenges to be overcome. Properties, such as
thermal variability, water vapor, fragility, and resistance to
melting must be optimized. The difficulties previously
mentioned have encouraged research on bioplastic functionality improvements. The use of cellulose, nanoparticles,
and chemical modifications are some of the mechanisms
employed to reduce the limitations of bioplastics (Siracusa
et al. 2008; Sartore et al. 2015). On the other hand, to create
a low-cost bioplastic with mechanical characteristics same as
those of synthetic plastic materials, e.g., polyethylene and
polypropylene is very difficult.
From rice straw, bioplastics rich in cellulose can be
produced. After pretreatment with trifluoroacetic acid (TFA),
the cellulose present in the rice straw is extracted to produce
bioplastic (Sartore et al. 2016). TFA is an organic acid
solvent for cellulose (Bayer et al. 2014). Furthermore, it can
be simply recycled via distillation and added to other organic
solvents, for example, water.
4.2 Soy Protein Bioplastics Applied
to Commercial Polyethylene
Artificial plastics produced from petroleum have several
beneficial properties, e.g., in cost terms, ease of processing,
and mechanical strength, and are produced globally in large
quantities (Zhao et al. 2007). These artificial plastics have
applications for several types of products, such as industrial
components and throw away materials. However, as plastics
are primarily derived from petroleum, due to the overuse of
this resource, carbon dioxide, and other toxic compounds are
released into environment during production, and this is a
major problem.
In addition, synthetics plastics, such as polyethylene,
polypropylene, and polyvinyl chloride present low degradability in environment and may remain for hundreds of years
(Emadian et al. 2017; Thompson et al. 2009; Hester and
Harrison 2018). Plastic waste polluting the ocean is also a
major global contamination problem (Thompson et al. 2009;
Luckachan and Pillai 2011). Therefore, an alternative to
using plastic is the artificial plastic or bioplastic, which is
composed of natural biopolymers (Thompson et al. 2009;
Hester and Harrison 2018). Bioplastics are biopolymers
produced from renewable biomass sources, such as wood,
natural rubber, carbohydrates, food waste, and proteins (Pico
and Barcelo 2019; Xu et al. 2019; Lambert and Wagner
2017). In addition, biopolymers are easily obtained from
nature, so there are no costs compared to synthetic polymers.
Biopolymers are not dangerous to humans and are ecofriendly materials. Therefore, bioplastics composed of
biopolymers, for example, starch Brodin et al. (2017),
agarose Sagnelli et al. (2016), casein Awadhiya et al. (2016),
lignin Sutermeister and Browne (1939), and keratin Kai et al.
(2016) are great alternatives to synthetic plastic.
Soybean is one of the more cultivated plants in the world,
especially in East Asia, where it is consumed as tofu (unfermented food), but also as miso and soy sauce (fermented
food). However, soybeans contain good fat (20%) and protein (35%) contents (Ramakrishnan et al. 2018; El-Shemy
2013). Therefore, soybeans are used worldwide for oil.
Ungreased soybeans contain many proteins. The residues of
ungreased soybeans are largely discarded, even though they
are used for human and as animal feed (Ramakrishnan et al.
2018). Degreased soybeans have been utilized to prepare
cellulosic materials (Visakh and Nazarenko 1998), glycerol
(Paetau et al. 1994), polyacrylamide (Tian et al. 2012), and
graphene (Xu et al. 2015). However, the treatments applied
to produce the cellulosic material from degreased soybean
are complex. Therefore, to green chemistry to prepare bioplastics by a simple process is an ideal way to minimize
contamination.
Soybean protein is basically composed of lysine and
arginine, neutral amino acids, such as glycine, valine, alanine, and leucine, and also aspartic and glutamic amino acids
(Jiang et al. 2016). The carboxyl or amino acid groups in the
residues are modifiable functional groups. In particular,
under moderate conditions, formaldehyde reacts with amino
groups to produce methylol, and forming a methylene
cross-link, e.g., N-CH 2 -N (Yamada et al. 2020; Taira 1973;
290
A. A. Santana et al.