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Biopolymers-Based Nanocomposites: Functions and Applications
Published in Shiji Mathew, E.K. Radhakrishnan, Nano-Innovations in Food Packaging, 2023
Alka Yadav, Gauravi Agarkar, Luiza Helena Da Silva Martins, Mahendra Rai
Polymers form a very important part of our daily life ranging from rubber, plastics, to resins, and adhesives (Mohan et al., 2016). The word polymer is taken from a Greek word “Poly” that means “many” and “mers” are “parts or units” (Goudoulas, 2012). Thus, polymers can be explained as any class of synthetic or natural material composed of multiple assemblies of a simple structural unit termed as monomers (Beisl et al., 2017; Bertolino et al., 2018). The reaction due to which the monomers join to form a polymer is known as polymerization reaction. Polymers can be fabricated using a number of materials including ethylene, propylene, starch, cellulose, and gelatin (Bibi et al., 2019). Polymers possess different chemical structures, mechanical, physical, and thermal properties (Carvalho et al., 2019). Polymers can be divided into synthetic and natural or biologically originated polymers (Maitz et al., 2015).
Organic Air Pollutants
Published in Stanley E. Manahan, Environmental Chemistry, 2022
These compounds are used primarily as monomers, which are polymerized to create polymers for plastics (polyethylene, polypropylene, polystyrene), synthetic rubber (styrenebutadiene, polybutadiene), latex paints (styrenebutadiene), and other applications. All of these compounds, as well as others manufactured in lesser quantities, get released into the atmosphere from production and manufacturing operations. In addition to the direct release of alkenes, these hydrocarbons are commonly produced by the partial combustion and “cracking” at high temperatures of alkanes, particularly in the internal combustion engine.
Organic Chemistry
Published in Steven L. Hoenig, Basic Chemical Concepts and Tables, 2019
An addition polymer is a polymer formed when monomer units are linked through addition reactions; all atoms present in the monomer are retained in the polymer.less reactive than their monomers, because the unsaturated alkene monomers have been transformed into saturated carbon skeletons of alkanes;forces of attraction are largely van der Waals attractions, which are individually weak, allowing the polymer chains to slide along each other, rendering them flexible and stretchable.
Fabrication of polymer-based self-assembly nanocarriers loaded with a crizotinib and gemcitabine: potential therapeutics for the treatment of endometrial cancer
Published in Journal of Biomaterials Science, Polymer Edition, 2022
Jiaolin Yang, Hongrui Guo, Jing Lei, Sanyuan Zhang, Shaoguo Zhang, Jirong Bai, Sufen Li
According to the features of a nanoparticle delivery structure mentioned earlier, the investigation into the use of diverse materials, as a nanocarrier precursor, is a critical necessity to enhance the adaptability and results obtained by such systems [19–21]. Polymers are macromolecules that comprise a linear or a branching chain, produced by the covalent union of one or many kinds of the unit known as monomers. These monomers may have any structure if they contain two functional groups, at least when they can react with another monomer [22]. Ideally, a polymer might be produced to achieve specific characteristics by selecting the correct type of monomer. Polymers include a particular sort of substance and allow the researchers to adapt them according to needs or ultimate purposes due to their highly synthetic versatility [22–25]. Polymeric tailoring may be carried out on biopolymers directly by chemical derivation to achieve characteristics. The fabrication of polymeric materials from their monomers is another approach, resulting in a wide variety of structures and uses. Therefore, nanotechnology generally takes on more importance polymeric materials and is employed for drug delivery systems as a promising nanoparticle [22–28].
Evolution in the surface modification of textiles: a review
Published in Textile Progress, 2018
Ayoub Nadi, Aicha Boukhriss, Aziz Bentis, Ezzoubeir Jabrane, Said Gmouh
Homopolymerization generally denotes the formation of a linear polymer formed from a monomer or an oligomer, and may be accomplished in many ways, including addition polymerization, step-growth polymerization and ring-opening polymerization. Addition polymerization describes the method where monomers are added one-by-one to an active site on the growing chain. In step-growth polymerization, the molecular weight of the polymer chain builds up slowly and there is only one reaction mechanism for the formation of polymer; ring-opening polymerization is a reaction in which the rings of cyclic monomers are opened, allowing them to be joined together linearly. The polymer types used for affixing these homopolymers to the fibre are diverse, namely polyurethane, polydimethylsiloxane and polyacrylic acid [40].
Revisiting the Early History of Synthetic Polymers: Critiques and New Insights
Published in Ambix, 2018
All of the synthetic polymers hitherto well treated in the early period of macromolecules (such as polystyrene, polyisoprene, and poly(vinyl chloride)) are examples of materials now known as “addition” polymers, one of two general polymer class designations introduced by the DuPont chemist Wallace Carothers (1896–1937) in 1929.82 Polymers in this class are produced by various forms of addition polymerisation,83 in which monomers are converted to the corresponding polymer without the generation of a secondary by-product. Mechanistically, the majority of addition polymers are generated via “chain-growth” polymerisation, in which the polymer chain grows by the addition of sequential monomers to the active end of the polymer chain.