Synthetic polymers materials, kinds

Polymers are divided into biological and non-biological (synthetic) polymers, each of which is of great importance in our life. Biological polymers form the foundation of our life and provide much food for us. Nowadays, synthetic polymers, hereafter called polymers, are widely applied in various fields because of their irreplaceable physicochemical properties. Transdermal delivery system (TDS) technology is built by combining various kinds of synthetic polymer materials, as described later. 

The chitin has limited applications besides such traditional purposes. Therefore, considerable efforts have been still devoted to compatibilization of chitin with synthetic polymers to provide cMtin-based new functional materials. As one of the possible applications of the present chitin nanofiber film, therefore, attempts were made to prepare the chitin nanoilber composite materials with synthetic polymers. Two kinds of approaches, that is, physical and chemical approaches have been considered to yield the polysaccharide-synthetic polymer composite materials (Figure 8). In former case, the polysaccharide and synthetic polymer chains construct material components by physical interaction in the composites, whereas the latter approach results in the formation covalent linkages between two polymer chains in the composites. 

Recently, the development of new functional materials from renewable resources such as various kinds of saccharides has received remarkable interest 1, 2, 3). Various types of synthetic polymer containing saccharides have been investigated ( , 5). There are two types of sugar-based polymers (i) sugar-containing linear polymer (ii) polymer with sugar pendant (Figure 1). 

In 1996, Wacker-Chemie-GmbH Co. Ltd in Germany developed an active CD, and immobilized it to the cellulose by dipping and padding. This kind of novel CD could be applied to modify not only the cellulose, starch, gelatin and other natural polymer materials, but also the polyester, polyamide, polypropylene and other synthetic fibers. Therefore, they could be used in different functional materials if treated appropriately. For example, a kind of fiber-CDPs encapsulated squalane was developed in Japan. Despite repeated washing, encapsulated squalane was able to maintain the moisturizing capabilities. 

Bio-based materials are receiving wide attention, in consequence innovative technologies and competitive industrial products are reducing the dependence on petrochemicals for the production of polymers. Increasing concerns about the environmental degradation caused by conventional polymers have directed worldwide research toward renewable resources. Natural polymers are one of the readily available alternatives for the synthesis path of polyurethanes. The functional groups present in this kind of polymer can be activated for condensation polymerizations, and polyurethane is produced by this route. The incorporation of moieties from natural polymers into the synthetic polymer chain allows tailoring of the properties of polyurethane products for widespread application. 

Contrary to the usual organic compounds, polymers are far from being homogeneuos maferials (i.e., polymer chains do not possess the same molar mass and chemical structure). As matter of fact, many synthetic polymers are heterogeneous in several respects. Homopolymers may exhibit both molar-mass distribution (MMD) and end-groups (EG) distribution. Copolymers may also show chemical composition distribution (CCD) and functionality distribution (FTD) in addition to the MMD. Therefore, different kinds of heterogeneity need to be investigated in order to proceed to the structural and molecular characterization of polymeric materials. 

Leo Baekeland patented the first totally synthetic polymer, which he called Bakelite, in 1910 (Figure 27.1). Bakelite is a versatile, durable material prepared from low-cost materials (phenol and formaldehyde) and was the most successful synthetic material of its kind for many years. 

If these projected uses are to be realized, a body of fundamental knowledge concerning polymer-cell surface interactions must be developed. The flexibility available to synthetic polymer chemists interested in preparing materials with useful biological properties is immense, but at this point we just do not know what kinds of polymers to make. There are a number of very general empirical rules, but their power is limited. 

Cellulose is one of the oldest materials used to produce fibers, filaments, and yams, from which fabrics of all kinds are manufacmred. Today s filament and yam production is a field for both natural and synthetic polymers [31]. All fibers used today have a compact microstracture and a very large aspect ratio. In contrast to these, Schmenk et al. [34] and Hacker et al. [35] produced an open porous, nanostmctured filament of cellulose aerogel for the first time using a sol-gel routine as described above for mmioliths and different spinning techniques. 

The effects shown by contacting the foreign surface in the coagulation of blood have been further complicated by the use of the kinds of polymers in some investigations with resultant scattering of data ". In addition, we studied the functional effects of exposure of blood coagulation factors and platelets to the surfaces of synthetic polymers from the viewpoint that extrapolation from the behaviors in vitro to their antithrombogenic behaviors in vivo would allow prediction of clinical usefulness of candidate materials. /... 

Chemical modification changes the types of atoms or groups of atoms and their combination in the molecular chains through chemical reactions of polymers. The polymer material itself is a kind of chemical synthetic material, so it can be modified by a chemical method. After chemical modification, the structure of the molecular chain changes and the polymer material has acquired new properties and its application field is expanded. 

---