Resins, plastic, definition

Definition Random copolymer produced by interaction of 17 moles ethylene oxide with 6 moles of propylene oxide Toxicology TSCA listed Uses Solvent in cosmetics lubricant for antiperspirants emollient bodying agent lubricant for textile spin finishes intermediate for prep, of resins, plasticizers, modifiers, and surfactants demulsifier food-pkg. adhesives, animal glues defoamer in food-contact paper/paperboard... 

Vinyl chloride homopolymer Vinyl chloride polymer Vinyl chloride resin Vinyon Definition Synthetic thermoplastic high polymer in rigid, plasticized, std. and high impact grades resist, to weathering, moisture, most acids, fats, petrol, hydrocarbons, fungus dimensionally stable good dielec, props. 

Plastics are subidivided into two types thermoplastic and thermosetting. The thermoplastics can be softened by heat and hardened again by subsequent cooling. This process is reversible and can be repeated many times. By contrast, the thermosetting resins are first softened and melted and, at subsequent heating to a definite temperature, they are irreversibly hardened, becoming insoluble [53]. 

For a field of scientific and engineering endeavor, polymers have one of the more sloppy sets of nomenclature. Ask six people in the business to give you definitions of resins and plastics, and you ll get at least six different answers. Almost everyone will tell you that they re both polymers, and that s right. Some will tell you they re interchangeable. Strictly spealdng, they re wrong. 

If you trace the word resin back far enough, you ll find that it was originally defined as a low molecular weight, natural polymer that is an exudate of (it exudes from) vegetable or non-vegetable matter. Examples are rosin (from pine trees), shellac (from insects), and both frankincense and myrrh (aromatic gums from an East African and an Asian species of tree). Resins like these do not flow if heat and pressure are applied, like plastics do. They decompose or melt. (This definition of resin is obsolete in commerce today.)... 

So you ll get no neat definition of resins and plastics here. But you ll know to be careful when someone else uses either term. Now, as for polymer, that s defined as a high molecular weight molecule formed by joining, in a repetitive pattern, one or more types of smaller molecules. 

This stable compd was found to be suitable for prepn of esters and resinous compositions for plastics, or it could be nitrated for conversion into a stable explosive of definite composition, which.is described here under Dipentaerythritol Hexanitrate... 

RESINS (Synthetic). A manufactured high polymer resulting from a chemical reaction between two (or more) substances, usually with heat or a catalyst. This definition includes synthetic rubbers and silicones (elastomers), but excludes modified, water soluble polymers (often called resins). Distinction should be made between a synthetic resin and a plastic the formei is the polymer itself, whereas the latter is the polymer plus such additives as niters, colorant, plasticizers etc. See also Elastomers and Plasticizers. 

Commercial Plastisols, Accdg to definition given in Ref 2, a plastisol is a liquid dispersion of finely divided resin in a plasticizer. It is usually 100% solid with no volatiles when volatile content exceeds 5% of the total wt it is called organosol. When the plastisol is heated, the plasticizer solvates the resin particles, and the mass gels. With continued application of heat the mass fuses to become a conventional thermoplastic material... 

Put very simply, copal is young version of amber. There is no definite age at which copal turns into amber, as the process is continuous firom the moment the resin appears on the tree and begins to solidify. In physical terms, when the resin is sufficiently cross-linked and polymerised it becomes amber (see Chapter 13, Plastics ). In other words, the resin has dried out and hardened. This process takes thousands if not millions of years, and not all copal becomes amber as much of it disintegrates with time. Furthermore, as the process is such a long one it is not possible for us to follow it or to replicate it in a laboratory, so there is still much that is speculation. We know, however, that there are some instances of copal that have begun to look like, and take on, the properties of amber. 

Alkyd resins have been the workhorse for the coatings industry over the last half century. The term alkyd was coined to define the reaction product of polyhydric alcohols and polybasic acids, in other words, polyesters. However, its definition has been narrowed to include only those polyesters containing monobasic acids, usually long-chain fatty acids. Thus thermoplastic polyesters typified by polyethylene terephthalate (PET) used in synthetic fibers, films, and plastics and unsaturated polyesters typified by the condensation product of glycols and unsaturated dibasic acids (which are widely used in conjunction with vinylic monomers in making sheet molding compounds or other thermosetting molded plastics) are not considered as part of the alkyd family and are beyond the scope of the present discussion. 

Both the terms resin and plastic are in common use but there are no explicit definitions for them. The term resin originally referred to vegetable-derived organic products of relatively high molecular weight, the best known of which are rosin and balsam obtained from coniferous trees. But, the term is now used much more broadly, and rather loosely, to include the manmade polymeric substances used in a variety of applications, such as in plastics, textiles, and paints. It is often used interchangeably with the term plastic . 

Pure resins are rarely processed into final products without the addition of selected compounds, called additives, which are incorporated during the process of extrusion and molding of a plastic resin or applied externally on the formed material. Compounding refers to the process of uniformly mixing the additives into the resin. A blend, by definition, is formed from two or more polymer resins which have been mixed together. 

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