Environmental polymer engineering

Keywords Characteristics of Plastics, Characterization, Classification, Economic data. Environmental Polymer Engineering... 

We regard the essential aspects of chemical reaction engineering to include multiple reactions, energy management, and catalytic processes so we regard the first seven chapters as the core material in a course. Then the final five chapters consider topics such as environmental, polymer, sohds, biological, and combustion reactions and reactors, subjects that may be considered optional in an introductory course. We recommend that an instmctor attempt to complete the first seven chapters within perhaps 3/4 of a term to allow time to select from these topics and chapters. The final chapter on multiphase reactors is of course very important, but our intent is only to introduce some of the ideas that are important in its design. 

For further information on the Environmental Stress Cracking of a PBT/PBA copoly (ester ester) it is expected that a second article will be published in Polymer Engineering Science in the year 2003. 

Abstract This chapter defines Environmentally Friendly Polymer Engineering as the basic organizational system of the first volume of these two books. The classification of plastics, and a list of their main characteristics, follows. This chapter closes with some economic data. 

Chem. Descrip. Rare earth-based inorg. pigment Uses Pigment for polymers, engineering plastics, industrial coatings Features High performance Environmental Environmentally responsible Rhodia Neolor Red [Ferro/Perf. Pigments]... 

Hiraishi, A. (2010) Environmental applications, in Poly(Lactic Acid) Synthesis, Structures, Properties, Processing, and Applications (Wiley Series on Polymer Engineering and Technology) (eds R. Auras, L.-T. Lim, S.E.M. Selke and H. Tsuji), John Wiley Sons, Inc., NJ, pp. 477 86. 

Melchior S et al. (2001) A comparison of traditional clay barriers and the polymer-modified material trisoplast in landfill covers. In Cossu R et al. (eds) Proceedings Sardinia 2001, Eighth Intemarional waste management and landfill symposium. Environmental Sanitary Engineering Center (CISA), Caghari (Italy)... 

Ishai, O. (1975). Environmental effects on deformation, strength, and degradation of unidirectional glass-fibre reinforced plastics. I. 8urvey, Polymer Engineering and Science, 15,486-490. doi 10.1002/pen.760150703... 

As regards the general behaviour of polymers, it is widely recognised that crystalline plastics offer better environmental resistance than amorphous plastics. This is as a direct result of the different structural morphology of these two classes of material (see Appendix A). Therefore engineering plastics which are also crystalline e.g. Nylon 66 are at an immediate advantage because they can offer an attractive combination of load-bearing capability and an inherent chemical resistance. In this respect the arrival of crystalline plastics such as PEEK and polyphenylene sulfide (PPS) has set new standards in environmental resistance, albeit at a price. At room temperature there is no known solvent for PPS, and PEEK is only attacked by 98% sulphuric acid. 

Many engineering thermoplastics (e.g., polysulfone, polycarbonate, etc.) have limited utility in applications that require exposure to chemical environments. Environmental stress cracking [13] occurs when a stressed polymer is exposed to solvents. Poly(aryl ether phenylquin-oxalines) [27] and poly(aryl ether benzoxazoles) [60] show poor resistance to environmental stress cracking in the presence of acetone, chloroform, etc. This is expected because these structures are amorphous, and there is no crystallinity or liquid crystalline type structure to give solvent resistance. Thus, these materials may have limited utility in processes or applications that require multiple solvent coatings or exposures, whereas acetylene terminated polyaryl ethers [13] exhibit excellent processability, high adhesive properties, and good resistance to hydraulic fluid. 

By means of genetic engineering, including cloning and site-directed mutagenesis, it has become possible for modern synthetic chemists to utilize a sufficient amount of isolated enzyme catalysts and to modify the reactivity, stability, or even specificity of enzymes. Therefore, polymerizations catalyzed by isolated enzyme are expected to create a new area of precision polymer syntheses. Furthermore, enzymatic polymerizations have great potential as an environmentally friendly synthetic process of polymeric materials. 

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