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Agricultural Waste Reinforced Polyethylene-Based Hybrid Nanocomposites: Design Formulations and Mechanical Properties
Published in Sefiu Adekunle Bello, Hybrid Polymeric Nanocomposites from Agricultural Waste, 2023
Stephen Durowaye, Ademola Agbeleye, Babatunde Bolasodun, Eniola Apena
Polyethylene is a thermoplastic polymer with long chain hydrocarbons. It is classified into several varieties based on density and branching. Some of the common varieties of polyethylene are low-density polyethylene (LDPE), high-density polyethylene (HDPE), and ultra-high molecular weight polyethylene (UHMWPE). LDPE is a branched thermoplastic with many relatively long branches of the main molecular chain. It is flexible and has low tensile and compressive strength compared to HDPE because of irregular packing of polymer chains. Generally, LDPE is used in food packaging materials, rigid containers, and plastic bags [2]. HDPE consists of chains without major branching. HDPE is more rigid than LDPE because of its high crystallinity content and it is used in packaging such as detergent bottles, milk jugs, garbage containers, and water pipes [2]. UHMWPE contains repeating units of polyethylene [-(CH2-CH2)n-] and its molecular chain can be seen as a twisted string of wires. It is used in aerospace, automotive, production of safety materials, etc.
Benefits of Nanocomposite Food Packaging Over Conventional Packaging
Published in Shiji Mathew, E.K. Radhakrishnan, Nano-Innovations in Food Packaging, 2023
Polyethylene is the most simple, versatile, and inexpensive plastic synthesized by the polymerization of ethylene. They are majorly classified into low-density polyethylene (LDPE), high-density polyethylene (HDPE), and linear LDPE (LLDPE) based on the density, crystallinity and chain branching. LDPE is usually used as a film for packaging fresh produce because of its heat sealability, inert, and odor-free properties. It can act as a good moisture barrier but is moderately permeable to oxygen and is a poor odor barrier. HDPE molecules can fold and pack into a highly crystalline structure making it brittle. It is a better barrier to gases and moisture comparatively. It has higher melting point, greater tensile strength, and better chemical resistance. They are blow-molded to make plastic bottles for substances such as water or milk, food containers (Paine and Paine, 1992).
Introduction to Thermoplastic Composites
Published in R. Alagirusamy, Flexible Towpregs and Their Thermoplastic Composites, 2022
The molecular weight of PE has a great influence on the properties of PE. Thus, it is important to know the structure and properties of PE to control and modify the properties of PE composites for different applications. The LDPE has a branched molecular structure, which prevents the close packing of the molecules and ultimately resulted in low crystallinity. LDPE is flexible and has low tensile and compressive strength. LDPE is generally used in food packaging materials, plastic film and rigid container applications. On other hand, UHMWPE has no branch in the molecular chain. Thus, it has the highest density and crystallinity percentage among all polymers. UHMWPE is available in powder and in film form. It has very good resistance to wear and impact properties and because of that it finds wide industrial applications (Pleşa et al. 2019).
Mechanical, thermal, and morphological properties of low-density polyethylene nanocomposites reinforced with montmorillonite: Fabrication and characterizations
Published in Cogent Engineering, 2023
Safaa Kh. Al-Jumaili, Wasan A. Alkaron, Maithem Y. Atshan
The experimental results of the tensile test for pure LDPE and LDPE with different amounts of MMT as a filler are given in Figure 6. The results showed a general comparison between the tested samples. The tensile test was done to measure the tensile strength of LDPE which can be defined as a material’s resistance to breaking under tension. Theoretically, LDPE has a low tensile strength due to its highly branched polymer chains. The branching, however, prevents the chains from stacking correctly beside one another, thus reducing the intermolecular forces of attraction between them, which reduces the resistance ability. From Figure 6, it can be seen that the stress–strain curve rises with an increase in the elongation percentage and the different amounts of MMT to an optimal point where the tensile strength levels. Continued addition of the elongation percentage beyond the threshold to LDPE decreases the tensile strength.
Characterization of low-density polyethylene (LDPE) films degraded using bacteria strains isolated from oil-contaminated soil
Published in Environmental Technology, 2023
Godswill E. Akhigbe, Adebisi E. EnochOghene, Kayode O. Olumurewa, Oluwasegun B. Koleoso, Ngozi D. Ogbonna
Plastics are cheap durable polymer materials consisting of synthetic and semi-synthetic compounds mostly derived from petrochemicals and are commonly used in every household and everyday activities [1]. Polyethylene plastics make up a larger percentage of synthetic polymer production all over the world, of which a bulk contains low-density polyethylene (LDPE) plastics [2,3]. It has become increasingly difficult to do without plastics in our everyday life, due to their characteristic nature, and flexibility. They are known to be odorless, transparent, highly flexible even at low temperature, high impermeability by water vapor, and chemically inert at room temperature. Some of its properties are due to its degree of crystallinity which ranges between 50% and 60% [4]. LDPE is prepared by polymerization of ethylene at high pressure and is utilized for diverse purposes such as packaging material for foods, snacks, medical products, handy bag, agricultural products, electronics and mechanical products [2,45]. They are persistent and not easily degraded in the environment, due to its high molecular weight, long chain carbon atoms, degree of crystallinity and hydrophobic nature [46].
Physical, rheological and microstructural properties of waste LDPE and TEOA modified bitumens
Published in Journal of the Chinese Institute of Engineers, 2022
Tacettin Geçkil, Ceren Beyza İnce, Mehmet Mahmut Tanyıldızı
As it is known, the most widely produced and used plastic types in the world are polyethylene terephthalate (PET), low density polyethylene (LDPE), high density polyethylene (HDPE), polyvinyl chloride (PVC), polypropylene (PP) and polystyrene (PS) (Alam et al. 2021; Almeida et al. 2020; Behl, Sharma, and Kumar 2014; Leng et al. 2018; Wu and Montalvo 2021). The vast majority of these plastics (nearly 40%) are composed of LDPE-based plastics, which have a shorter lifespan compared to other plastics and constitute 50% of the packaging industry (Almeida et al. 2020). LDPE is used in many areas varying from storage and laboratory containers to beverage cans, from computer parts to carrier bags used in shopping (Abhijith et al. 2019; Nejres, Mustafa, and Aldewachi 2020). LDPE, which has a 50–60% crystalline solid structure, is a material that is resistant to chemicals, opaque, odorless, heat-proof and has minimum vapor permeability. Due to the small amount of branching in the chain structure, it shows flexible properties even at low temperatures (Sen and Raut 2015).