Structure and properties of plastics

In a more detailed consideration of properties, there is interaction between those dependent on short-range interactions and, in particular, the nature of the repeat unit in the polymer and the constraints imposed by the chain or network structure. For example, the density of a plastic is that expected of an organic substance (0.8 to 1.4 Mg m ). On cooling, the material changes density continuously as it strives towards equilibrium, but is constrained by the polymer structure. This time dependence is characteristic of polymers, particularly thermoplastics, and is a factor of considerable importance in their technology. 

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Kulinski, Z. and Piorkowska, E. 2005. Crystallization, structure and properties of plasticized poly(L-lactide). Polymer 46 10290-10300. 

The importance of plastics is attested by the abundance of scientific and technical literature on the subject. For several reasons the following discussion on the manufacture, structure and properties of plastics is necessarily a brief introduction to the subject as found in the literature ... 

Subsequent chapters deal with individual classes of plastics. In each case a review is given of the preparation, structure and properties of the material. In order to prevent the book from becoming too large I have omitted detailed discussion of processing techniques. Instead, with each major class of material an indication is given of the main processing characteristics. The applications of the various materials are considered in the light of the merits and the demerits of the material. 

TPEs from blends of rubber and plastics constitute an important category of TPEs. These can be prepared either by the melt mixing of plastics and rubbers in an internal mixer or by solvent casting from a suitable solvent. The commonly used plastics and rubbers include polypropylene (PP), polyethylene (PE), polystyrene (PS), nylon, ethylene propylene diene monomer rubber (EPDM), natural rubber (NR), butyl rubber, nitrile rubber, etc. TPEs from blends of rubbers and plastics have certain typical advantages over the other TPEs. In this case, the required properties can easily be achieved by the proper selection of rubbers and plastics and by the proper change in their ratios. The overall performance of the resultant TPEs can be improved by changing the phase structure and crystallinity of plastics and also by the proper incorporation of suitable fillers, crosslinkers, and interfacial agents. 

It is widely appreciated that the deterioration of metal and plastic implant materials within the body is one of the most important aspects of implant surgery. This particular application of materials places an almost unique demand on the resistance to deterioration. The reasons are basically twofold, for not only may the environmental effects alter the structure and properties of the material, which may itself affect the function of the implant and hence the well-being of the patient, but also the by-products of any structural change may have harmful effects on the patient... 

Presented in this paper are the results of an investigation concerning the link between structure and properties of rubber-toughened plastics. An attempt has been made to assess the importance of the spatial distribution of rubber particles in terms of their effectiveness in controlling craze initiation and growth. Also studied in particular were the effects of rubber particle size on the mechanical properties of HIPS materials. A... 

V(acac)3 has several applications, including its use as a component in olefin polymerization catalysts it is air sensitive, undergoing gradual oxidation in moist air to give VO(acac)2. Commercial V(acac)3 is allowed to contain not more than 2.0 wt% of VO(acac)2. Several spectroscopic techniques, such as IR, ESR and NMR, have been used to study the structure and properties of V(acac)3. IR and H NMR spectrometries were used effectively for determination of VO(acac)2 in V(acac)3 however, IR showed lower LOD . FT-NIR spectroscopy was used for the determination of calcium ascorbate in blister packs, tablets, plastic bottles etc.. ... 

In investigations of the structure and properties of disperse materials, particularly plastic foams, it is necessary to find out the distribution pattern of one phase in the material. It is simpler to consider the distribution of the gas phase in a solid body, i.e. the gas-filled cell distribution within a foam bulk] In their turn, the cells, as shown above, may be characterized by several parameters (size, shape, volume and surface area). The cell size distribution pattern is the most comprehensive characteristic of the dispersity of the gas structural elements of plastics. Furthermore, the cell size can, be determined by one of the methods which will be discussed below, and the foam dispersity is expressed in terms of the nominal cell diameter distribution function. 

As noted above, the adequate simulation of the cellular structure of plastic foams is very important for the investigation of the relation between structure and properties of foamed plastics. A solution to this problem would allow to establish not... 

Frisch, K.C., "Relationship of Chemical Structure and Properties of Rigid Urethane Foams," Journal of Cellular Plastics, 1(2) 325-330 (April 1965). 

Parikh, D. R. Edmondson, M. S. Smith, B. W. Winter, J. M. Castille, M. J. Magee, J. M. Patel, R. M. Karajala, T. P. Structure and Properties of Single-site Constrained Geometry Ethylene-Propylene-Diene (EPDM) Elastomers. In Metallocene-catalyzed Polymers -Materials, Properties, Processing Markets, Benedikt, G. M., Goodall, B. L., Eds. Plastics Design Library New York, 1998 p 113. 

The theory of electronic excitation, which occurs during plastic deformation and fragmentation of crystals, is discussed by Molotskii [99]. The mechanochemistry of inorganic solids has been reviewed by Boldyrev et al. [100] with particular reference to the work done in The Institute of Solid State Chemistry at Novosibirsk. The consequences of mechanical activation on the structures and properties of selected spinels have been examined and the rate of the reaction forming barium tungstate investigated. Prospects for the future development of this subject are assessed. 

Considering basic science in the general field of plastics there are essentially three divisions—synthesis, molecular structure, and structure and properties of bulk polymers. 

Organic Coatings and Plastics Chemistry Division, the Colloid and Surface Chemistry Division and the Cellulose, Paper and Textile Division. We have also been joined in the Symposium by the High Polymer Physics Division of the American Physical Society and the Division of Engineering Structures and Properties of the Society of Plastics Engineers as well as two exceptional keynote speakers Dr. John D. Hoffman of the National Bureau of Standards and Dr. Field Winslow of Bell Telephone Laboratories. 

Abstract Clays are ubiquitous constituents of the Earth s crust that serve as raw materials for traditional ceramics. Mineralogically, clays are phyllosilicates or layered aluminosilicates. Bonding is strong within layers, but weak between layers, allowing clays to break into micrometer-sized particles. When mixed with water, clays develop plasticity and can be shaped easily and reproducibly. When heated, clays undergo a series of reactions that ultimately produce crystalline mullite and a silica-rich amorphous phase. Beyond the structure and properties of clays, the science that developed to understand traditional ceramics continues to serve as the framework for the study of advanced ceramics. 

Barrier plastics will be used as examples in this paper. Barrier and selectivity are two sides of the same coin. Both properties are determined by the same types of transport phenomena. [3] Similar techniques can, therefore, also be applied to study separation membranes. The same approximations are valid if the mixture flowing through the membrane is sufficiently dilute that (i) it does not significantly affect the structure and properties of the membrane, and (ii) the components of the mixture can be treated as independent penetrants. The same general approaches can also be applied to concentrated mixtures, but only provided that certain simplifying approximations are not made. 

This non-equilibrium chemical and physical (mechanical) state of inhibited plastics is caused by incorporated Cl and their carriers (PI) in concentrations exceeding the thermodynamic compatibility threshold with the polymer. The thermodynamic non-equilibrium is a useful property of inhibited plastics since it expands their anticorrosion functional features. The greater the deviation from the non-equilibrium state of such systems, the quicker the relaxation processes in them accompanied by the release of excess Cl into the ambient medium and to the object being protected. The structure and properties of the components of inhibited plastics Cl depend on their composition and can be carried to the mated part by either diffusion in the gaseous (thanks to Cl volatility) or liquid phase via its exudation, its mixture with a PI, or washing of water-soluble Cl and diffusion through the material moisture. These processes bring about mechanical relaxation of the polymer matrix. The point at which the inhibited anticorrosion material moves into a state of thermodynamic equilibrium is usually correlated with its protective ability. 

SOE 97b] van Soest J.J.G., Knooren N., Influence of glycerol and water content on the structure and properties of extruded starch plastic sheets during aging . Journal of Applied Polymer Science, vol. 64, no. 7, pp. 1411-1422,1997. 

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