Plastics chemical characteristics

Within the xTyIi y copolyamide series, it is interesting to analyse the chemical structure dependence of the plastic deformation characteristics. 

Scola DA (1985) Some chemical characteristics of the reverse Diels-Alder polyimide, PMR-15. In Gupta MR, Weber WD (eds) Polyimides synthesis, characterization and application (Proceedings of the Second International Conference on Polyimides). Society of Plastics Engineers, Inc, Hopewell Jet, p 247... 

Commodity Plastics // Additional Characteristics Heat Resistance Chemical Resistance Dimensional Stability... 

From here on this chapter expands the properties of various plastics, the means by which certain physical and chemical characteristics can be identified and quantified, together with the constituents which may be found in a plastic. The converting processes may contribute other factors relevant to the selection and clearance of a plastic pack. The chapter concludes by reference to sterilisation methods and references. (The next chapter places particular emphasis on the clearance of a plastic pack , and should be read in conjunction with this section.)... 

Irregularities of the deformation and strength properties of the polymer films upon the introduction of contact or volatile Cl are conditioned by the aggregate state and physical-chemical characteristics of the inhibitors, their concentration distribution in the polymer matrix and the presence of plasticizers. 

PI incorporated in inhibited plastics and Cl significantly influence the physical-mechanical and physical-chemical characteristics of materials. The three-component composition-property charts presented in Fig. 4.24 help to estimate the effect of Cl and PI on the mechanical and antirust properties of composites. 

Oxidation of plastics and rubber, mostly by heat and/or radiation, results in the breaking of chains and bonds (termed chain scission), and hence a deterioration of mechanical properties as well as changes in the chemical characteristics of the chains. Some polymers, such as PE and PP, are especially susceptible to oxidation, and must be specifically protected. 

Nashville,Tn., 19th-21st Jan.1998, Session 21-D. 627 UTILISING FOURIER TRANSFER NEAR INFRARED (FT-NIR) TO MONITOR KEY CHEMICAL CHARACTERISTICS IN THE MANUFACTURE OF THERMOSET PLASTICS Landis L P Cameron D G Premix Inc. DHC Analysis Inc. 

There are many more features of polymers that you may learn about as you proceed in your engineering curriculum. From the perspective of chemistry, they serve as a tremendous example of the impressive structural variability possible with carbon-based molecules. Although other elements can form polymeric materials, it is the chemical characteristics of carbon that make the modern plastics industry possible. 

Secondary recycling is the recycle of plastic resins into new products with less demanding physical and chemical characteristics than the original application. Mixed plastics are applied most easily in the secondary recycling market because less separation of resin types and less complicated production methods are necessary to achieve a finished product. The most readily recognized secondary plastic product is "plastic lumber" (thick extrusion molded slabs of resin in which some types of resins act as fillers). Plastic lumber is used to make park benches, fence posts, boat docks, playground equipment and the like. The fabrication of mixed plastic lumber is discussed in Part II of the book. 

The chemical characteristics of the starting low-molecular-weight species will determine the properties of the final polymer. The properties of different polymers can vary widely. Properties can be varied for each individual plastic material as well, simply by varying the microstructure of the material. In its solid form a polymer can take up different structures depending on the structure of the polymer chain as well as the processing conditions. 

---