OIL PALM NANOCELLULOSE HYDROGEL POTENTIAL (Pt 2)

OIL PALM (Elaeis guineensis) is among important commodity in Malaysia since long ago. Currently there are more than 1.4 million hectare of oil palm grown in Malaysia as one of the largest palm oil producers in the world. However, the Oil Palm Empty Fruit Bunch (OPEFB) is considered the cheapest natural fiber with good properties and exists abundantly in Malaysia. It has great potential as an alternative main raw material to substitute woody plants as an important industry. Currently it was told that the well-known Polymeric Hydrogel has gathered a lot of interest due to its three-dimensional (3D) cross-linked network with high porosity. However, for some issues regarding its performance such as poor interfacial connectivity and mechanical strength have been raised so that nanocellulose has been introduced. In some research done by many local institutions in which the plantation of oil palm in Malaysia is discussed to show the potential of OPEFB as a nanocellulose material in hydrogel production is potentially develop. Nanocellulose can be categorized into three nano-structured celluloses in which it differs in the processing method. The most popular nanocellulose hydrogel processing methods are in few techniques. The 3D printing method is taking the lead in current hydrogel production due to its high complexity and the need for hygiene products. Some of the latest advanced applications are used to show the high approach of commercialization potential of nanocellulose hydrogel products. There are challenges and future direction of nanocellulose hydrogel. OPEFB claimed has met the requirements of the marketplace and product value chains as nanocellulose raw materials in many ways for the hydrogel applications. This article at "Anim Agriculture Technology" I am happy to discuss about the potential of the oil palm nanocellulose hydrogel for implementation in Malaysia for the future and reading purposes.

A much research done on this matter the biodegradable and environmentally friendly products have garnered worldwide attention including the whole processing line especially in upfront sectors like automotive, textile, cosmetics, and packaging. Due to insufficient petroleum resources and the high price of wood as the main raw material, LBM is a suitable alternative in producing regenerated cellulose products. Cellulose is a linear homopolymer composed of 

d-anhydroglucopyranose units (AGUs) that consist of β (1- 4)-glycosidic bonds. Native cellulose in which is also known as cellulose I, is a semi-crystalline polymer composed in a parallel arrangement and is not the most stable crystalline form. Regenerated cellulose product, commonly known as cellulose II, has a similar molecular formula (C6H10O5)n as cellulose I, but is more stable and can be molded into specific products such as membranes, hydrogels, aerogels and fibers. Cellulose II is the results of dissolution and recrystallization where the cellulose chains adopt an anti-parallel arrangement structure, which is the most stable form. Regenerated cellulose is a material that is formed as a soluble cellulosic derivative including subsequent regeneration, typically in fiber, film, or gel-like forms, depending on their production methods and come from the conversion of natural cellulosic materials.

Hydrogels are usually made from petroleum-based synthetic polymers, either poly acryl amide (PAAM) or Poly Acrylic Acid (PAA). These polymers are less environmentally friendly due to their non-degradability. The extensive of the research on the modification of hydrogels has been undertaken by using natural polymers such as cellulose (polysaccharides), which is biodegradable, has good biocompatibility, is renewable, and non-toxic. The finding of study found where they have inferior mechanical properties compared to petroleum-based hydrogels. Several techniques to improve the mechanical properties of hydrogels include the incorporation of suitable natural polymers or other inorganic materials. In recent years, many nanomaterials have been introduced with promising great properties. These so-called nanomaterials are usually known as cellulose nanocrystal (CNC or NCC), bacterial nanocellulose (BNC), and cellulose nanofiber (CNF). To cater for issues like poor interfacial connectivity and the mechanical strength of the produced hydrogel, nanocellulose is introduced due to its impressive properties such as lighter weight, higher surface area-to-volume ratio, and higher stiffness and strength compared to cellulose. It also has the ability to form effective hydrogen bonds within other polymeric matrices as well as across the cellulose chains. Therefore, it is a promising material for use as a superior reinforcing material. The nanocellulose is incorporated as a reinforcing material into the polymer to form a cellulose fiber-reinforcement composite. CNF has micro-dimensions in length and nano dimensions in diameter compared to CNC, which has both a length and diameter in nanosize. This review focuses on the CNF from OPEFB as a nanomaterial incorporated in hydrogel for various applications due to its ultralight and highly porous characteristics and is capable of being employed in various industries such as agriculture, biomedical, tissue engineering, food, and biocomposites. CNF can be extracted via chemical or mechanical methods. The commonly used methods to produce CNF are explained in the next section. In particular, tailoring the swelling and mechanical properties of hydrogels to the needs of a specific application is essential to create versatile and high-performance functional materials. In addition, the formation of high modulus hydrogels (aside from specific composition combinations such as double network hydrogels) remains one of the barriers to the effective translation of hydrogels to practical applications. Furthermore, the apparent biological inertness of CNF makes them attractive in applications such as drug delivery systems, tissue engineering, scaffolds, and wound healing materials, all of which are particularly well-served by the high porosity, water content, and typical cytocompatibility of hydrogels.

However, with the usage of petroleum-based materials has raised concerns regarding human health issues such as greenhouse gas emissions, degradation time, depletion of energy resources, and endangered marine life. These issues nowadays have forced green technology development to use nature-friendly materials as an alternative for fossil-fuel based products. Thus, this review briefly discusses upgraded hydrogels for various high-end applications which are produced from potential eco-friendly raw materials (such as OPEFB including versatile nanocellulose additives) with the hope that it could contribute to a better future bioeconomy. Furthermore, the upgraded hydrogels have the potential to replace current synthetic products that are harmful to humans and other ecosystems. In fact, the increase worldwide demand for hydrogel usage has been forecasted for the year 2024. Moreover, the mechanical strength and stability including the porosity of the existing nanocellulose hydrogel have been successfully enhanced. However, extensive summaries focusing on the preparation of cellulose nanomaterial-based hydrogel/aerogel using OPEFB are still limited. Thus, this review highlights the potential usage of OPEFB as a main raw material for making hydrogels using recent several emerging methods such as 3D printing. This article is in 3 segments of Part 1, Part 2 and Part respectively.

Thanks.

By,

M Anem,

Putrajaya,

Malaysia.

(November 2022).