Plastics and Their Characteristics

TABLE 7.5 Common Phthalate Plasticizers and their Characteristics... 

As reviewed throughout this book, designing acceptable products requires knowledge of the behavior of the different plastics and their processing characteristics (Chapter 6, MATERIAL VARIABLE and Chapter 8 EQUIPMENT/PROCESSING VARIABLE). 

Some frequendy used resilient seats and their characteristics within SRVs Plastics ... 

In this chapter it will be demonstrated that there is a strict relation between the chemical composition of plastics and their pyrolysis oil, but the relationship is not well understood in many cases due to the fact that the products are determined by both the source and the pathway of decomposition. The ranking values of pyrolysis oils derived from plastics may be estimated on the basis of the correlation of major oil characteristics and chemical composition and structure of component compounds. 

Table VI compares the key properties of these two types of thermotropic polymers category by category. The samples compared had the same melting ranges, but were very different in reduced viscosities and solubility characteristics. The data compared were those processed under the most favorable conditions. Interestingly enough, the as-spun fibers from the polyester-carbonate can be heat-treated more efficiently than those fibers (of same tenacity) spun from the polyester. Both of them gave fiber properties far superior to those of nylons and polyethylene terephthalate. These two classes of polymers also had comparative properties (such as tensile strength, tensile modulus, flex modulus, notched Izod impact strength) as plastics and their properties were far superior to most plastics without any reinforcement.

The objectives of this chapter are to provide a basic knowledge of plastic materials, their characteristics which are likely to appertain to pharmaceuticals and the processes by which they are converted into packaging materials. 

This chapter reviews the general context of starch as a material. After a survey of the major sources of starch and their characteristic compositions in terms of amylase and amylopectin, the morphology of the granules and the techniques applied to disrupt them are critically examined. The use of starch for the production of polymeric materials covers the bulk of the chapter, including the major aspect of starch plasticization, the preparation and assessment of blends, the processing of thermoplastic starch (TPS), the problems associated with its degradation and the preparation of TPS composites and nanocomposites. The present and perspective applications of these biodegradable materials and the problems associated with their moisture sensitivity conclude this manuscript. 

Table 7.10 lists common recommended surface treatments for plastic adherends. These treatments are necessary when plastics are to be joined with adhesives. Specific surface treatments for certain plastics and their effect on surface property characteristics are discussed in Sec. 7.6. Details regarding the surface treatment process parameters may also be found in ASTM D-2093 and various texts on adhesive bonding of plastics. An excellent source of information regarding prebond surface treatments is the suppher of the plastic resin that is being joined. 

The major plastics that are plated and their characteristics for plating are identified in Table P.6. Improvements are being made continuously, especially in ABS and polypropylene, which yield generally lower product costs. Aside from the commercial plastics described in Table P.6, excellent plated products can be obtained with other plastics. Notable is the plating of TFE fluorocarbon, where otherwise unachievable electrical products of high quality are reproducibly made. Examples of applications are printed circuit boards, corona-free capacitors, and low-loss, high frequency electronic components. 

As it has been noted above, the main feature of polymers is that they consist of long chain macromolecules. Therefore, it is to be expected that polymer chains structure and their characteristics will be influenced essentially on bulk polymers properties. One of such polymer chain structural factors is availability in it of bulk side groups, which results to bulk polymers brittleness enhancement [40], A side groups effect on plasticity level for heterochain polymers was considered in Ref. [41], where brittleness increase was explained by side groups nonparticipation in local or macroscopic plasticity processes. 

Oxidative induction temperature and/or time is a property of plastics that is mainly determined by their stabilizers. Oxidative induction temperatures and times will be increasingly considered thanks to the introduction of the specification of the Geosynthetic Research Institute for geo-memhranes made from PE-HD (GRI-GM13) [176]. This specification requires that raw materials manufacturers provide the oxidative induction times and their characteristics for their products and on the basis of oven storage and UV storage tests [177]. 

Compatibility and solubility are characteristic properties of combinations of two or more materials. The fundamental studies of these properties are very important for solvents and plasticizers, and their results have been discussed in detail in monographic sources. ... 

The material in this book is included in our well-known Plastics Technology Handbook and it focuses on a wide range of polymers, both of common and special types, and their myriad applications. For readers who are not quite familiar with polymers and their characteristics, it would be advisable to read Plastics Fundamentals, Properties, and Testing, before taking up the present book. We thank Allison Shatkin, Materials Science and Chemical Engineering Editor at CRC Press/Taylor Francis, who first conceived the idea of this book and took the initiative in publishing it. 

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