Polymeric materials nature

Davis DA, Hamilton A, Yang J et al (2009) Force-induced activation of covalent bonds in mechanoresponsive polymeric materials. Nature 459 68-72... 

Health and safety information is available from the manufacturer of every adhesive sold in the United States. The toxicology of a particular adhesive is dependent upon its components, which mn the gamut of polymeric materials from natural products which often exhibit low toxicity to isocyanates which can cause severe allergic reactions. Toxicological information may be found in articles discussing the manufacture of the specific chemical compounds that comprise the adhesives. 

Polymers. Hydrocarbons from petroleum and natural gas serve as the raw material for virtually all polymeric materials commonly found in commerce, with the notable exception of rayon which is derived from cellulose extracted from wood pulp. Even with rayon, however, the cellulose is treated with acetic acid (qv), much of which is manufactured from ethylene (see Fibers, regenerated cellulosics). 

Engclopedia of Poljmer Science and Engineering Online John Wiley Sons, Inc. Dialog covers natural and synthetic polymeric materials... 

Alkyd resins are produced by reaction of a polybasic acid, such as phthaUc or maleic anhydride, with a polyhydric alcohol, such as glycerol, pentaerythritol, or glycol, in the presence of an oil or fatty acid. The resulting polymeric material can be further modified with other polymers and chemicals such as acryhcs, siUcones, and natural oils. On account of the broad selection of various polybasic acids, polyhydric alcohols, oils and fatty acids, and other modifying ingredients, many different types of alkyd resins can be produced that have a wide range of coating properties (see Alkyd resins). 

Electronic and Electrical Applications. Sulfolane has been tested quite extensively as the solvent in batteries (qv), particularly for lithium batteries. This is because of its high dielectric constant, low volatUity, exceUent solubilizing characteristics, and aprotic nature. These batteries usuaUy consist of anode, cathode polymeric material, aprotic solvent (sulfolane), and ionizable salt (145—156). Sulfolane has also been patented for use in a wide variety of other electronic and electrical appHcations, eg, as a coil-insulating component, solvent in electronic display devices, as capacitor impregnants, and as a solvent in electroplating baths (157—161). 

Polymeric materials derived from natural products. 

In addition to plastics materials, many fibres, surface coatings and rubbers are also basically high polymers, whilst in nature itself there is an abundance of polymeric material. Proteins, cellulose, starch, lignin and natural rubber are high polymers. The detailed structures of these materials are complex and highly sophisticated in comparison the synthetic polymers produced by man are crude in the quality of their molecular architecture. 

The need for temperature cycling should be taken into account when designing or conducting tests. The nature of the test vessel should be considered for tests in aqueous solutions at temperatures above about 60°C since soluble constituents of the test vessel material can inhibit or accelerate the corrosion process. An inhibiting effect of soluble species from glass, notably silica, on the behaviour of steel in hot water has been shown . Pure quartz or polymeric materials are often more appropriate for test vessel construction. 

Along with such materials as plastics, adhesives, fibers, and coatings. rubber is polymeric in nature. Such materials consist of long chains, with molecular masses generally of the order of 50,000 to 500,000 g/mol. Common rubbery materials—often called elastomers— include automotive tires and rubber bands. 

The remainder of this chapter will deal with natural polymers. These are large molecules, produced by plants and animals, that carry out the many life-sustaining processes in a living cell. The cell membranes of plants and the woody structure of trees are composed in large part of cellulose, a polymeric carbohydrate. We will look at the structures of a variety of different carbohydrates in Section 23.3. Another class of natural polymers are the proteins. Section 23.4 deals with these polymeric materials that make up our tissues, bone, blood, and even hair. ... 

Membranes used for the pressure driven separation processes, microfiltration (MF), ultrafiltration (UF) and reverse osmosis (RO), as well as those used for dialysis, are most commonly made of polymeric materials. Initially most such membranes were cellulosic in nature. These ate now being replaced by polyamide, polysulphone, polycarbonate and several other advanced polymers. These synthetic polymers have improved chemical stability and better resistance to microbial degradation. Membranes have most commonly been produced by a form of phase inversion known as immersion precipitation.11 This process has four main steps ... 

The third reason for opposition lay in the nature of many of the polymeric materials then known. Not oidy were they apparently ill-characterised, but they were also frequently non-crystalline, existing as gums and resins. Just the sort of unpromising media, in fact, from which dextrous organic chemists had become used to extracting crystalline substances of well characterised physical... 

Three factors affect the essential nature of a polymeric material and determine whether it is glassy, rubbery, or fibre-forming under a given set of conditions. These are ... 

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