Polymers are long chains of monomeric compounds that are produced by polymerisation of these monomers. Ranging from natural to synthetic, polymers play a very ubiquitous role in pharmaceutical sciences and chemistry. Polystyrene, nylon is some of the examples of synthetic polymers whereas DNA and proteins are called as biopolymers. A most common example of polymer is polythene bag. Natural compound materials like shellac, amber, wool, silk and natural rubber are used for hundreds of years. A spread of alternative natural polymers exists, like polysaccharide, that is that the main constituent of wood and paper. The list of artificial polymers includes India rubber, phenol aldehyde rosin (or Bakelite), neoprene, nylon, polyvinyl resin (PVC or vinyl), vinylbenzene, polythene, plastic, polyacrylonitrile, PVB, silicone, and plenty of additional. Most ordinarily, the ceaselessly coupled backbone of a chemical compound used for the preparation of plastics consists chiefly of carbon atoms. An easy example is polythene ('polythene' in British English), whose continuation unit is predicated on alkene compound. However, alternative structures do exist; for instance, parts like element type acquainted materials like silicones, examples playing around Putty and waterproof plumbing sealer. Gas is additionally ordinarily gift in chemical compound backbones, like those of polythene glycol, polysaccharides (in glycosidic bonds), and DNA (in phosphodiester bonds).
Open Access raises practical and policy questions for scholars, publishers, funders, and policymakers alike, including what the return on investment is when paying an article processing fee to publish in an Open Access articles, or whether investments into institutional repositories should be made and whether self-archiving should be made mandatory, as contemplated by some funders.
Last date updated on August, 2021