Chemical structure of plastics

Polymers are usually structured like spaghetti noodles piled together. There are two main types of polymers, amorphous or crystalline. Amorphous polymers are prepared by 

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The use of plastics as materials of construction has expanded rapidly in recent years and now they compete with metals, glass, and wood in many applications (see Table 1). The chemical structure of plastics is complicated, but most of them are polymers, that is they consist of large numbers of small, identical groups of atoms joined together to form one chain-like molecule. 

Environmental factors can cause significant changes to the chemical structure of plastics and result in the loss of properties during use over a period of time. 

Van Veersen GJ, Meulenberg AJ. The Relation Between the Chemical Structure of Plasticizers and their Performance in PVC. SPE Technical Papers 1972, p. 18, 314. 

Although it is very difficult and probably of little value to produce an adequate definition of the word plastics , it is profitable to consider the chemical structure of known plastics materials and try to see if they have any features in common. 

The chemical structures of the plasticizers are related to the properties they impart to polymers. 

It is an unfortunate fact that many students and indeed design engineers are reluctant to get involved with plastics because they have an image of complicated materials with structures described by complex chemical formulae. In fact it is not necessary to have a detailed knowledge of the structure of plastics in order to make good use of them. Perfectly acceptable designs are achieved provided one is familiar with their perfonnance characteristics in relation to the proposed service conditions. An awareness of the structure of plastics can assist in understanding why they exhibit a time-dependent response to an applied force, why acrylic is transparent and stiff whereas polyethylene is opaque and flexible, etc., but it is not necessary for one to be an expert... 

Adhesion is usually controlled by means of various finishing agents. Mikhalsky noted in [260] that reactions between such agents and thermoplastics are hindered for a number of reasons, one reason being that the chemical structure of the polymer is formed before the treated filler is added. In the majority of cases thermoplastics do not contain reactive groups, if perhaps only at the ends of macromolecules where they enjoy little mobility. The probability of contact between the reactive groups of the agent and the plastic. 

Typically, large-scale gas filling makes the main characteristics of foam plastics — coefficients of heat and temperature conductivity, dielectric permeability, and the tangent of the dielectric loss angle — totally independent of the chemical structure of the original polymer [1],... 

Tables 7-5 to 7-7 show that there are different orders of magnitude between plastics and metals. Depending on the application, plastics may be formulated and processed to exhibit a single property or a designed combination of electrical, mechanical, chemical, thermal, optical, aging properties, and others. The chemical structure of polymers and the various additives they incorporate provide compounds to meet many different performance requirements.

Sorption is defined as the bonding of a solute to a plastic. It is a physicochemical phenomenon related to the properties of the plastic and the chemical structure of the drug or other soluble components of the preparation. Interactions of this type can be determined by measuring the loss of the solute to the plastic at equilibrium under constant temperature conditions [11]. 

Fig. 18a. 11. Chemical structures of commonly used plasticizers in membranes of ion-selective electrodes. DOS, dioctyl sebacate NPOE, nitrophenyl octyl ether.

This paper rerports an investigation of the yield behavior of several amine and anhydride cured DGEBA resin systems. The Argon theory is used to assess the controlling molecular parameters from the experimental results. Such parameters are then compared with the known chemical structures of the resins. The mechanisms of plastic flow in thermoset polymers such as epoxies is demonstrated. 

Previous work hod shown that low temperature coke is formed from cools hooted to between 450° and 500° C. by a process of nudeation and growth of spherical bodies in the plastic vitrinite. An essentially similar process has now been found to occur with coke-oven and petroleum pitches, with polyvinyl chloride, and with some polynuclear hydrocarbons, all of which yield carbons which grophitize readily at high temperatures. The process is probably general for the initial stages of formation of such carbons from the liquid phase. Some control of the solidification process has been achieved on the laboratory scale, and the physical and chemical structure of the spherulites has been investigated. 

Pigment Red 177 [4051-63-2] has the chemical structure of 4,4 -diaminol,l -dianthraquinonyl and is prepared by intermolecular copper-catalyzed debromination of l-amino-4-bromoanthraquinone-2-sulfonic acid followed by desulfonation. It is the only known pigment with unsubstituted amino groups which are involved in both intra- and intermolecular hydrogen bonding (19). The bluish red pigment is used in plastics, industrial and automotive paints, and specialized inks (see Dyes, ANTHRAQUINONE). 

Graft copolymerizations have been often employed in industries of plastics, rubber, fiber, adhesives and so on. In most of these cases the gross polymerization product is subjected to processing without isolating the pure graft copolymer. It is well known that the physical properties of the product are closely related to its superstructure, which in turn is a function of both the content and the chemical structure of the graft copolymer present in the product. Therefore, the characterization of the graft copolymer is also desirable to control the product property. 

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