Materials Engineering Aspects

Although most polymers are in fact modified to a greater or lesser degree to optimize their utility in end-use applications, certain basic characteristics of these ethylene-styrene interpolymers make them particularly likely to be modified, or to be used as modifiers. These characteristics are as follows  

polymer chain microstructure, aromatic/olefin functionality and inherent compatibility with a wide range of other polymers, fillers and low molecular weight materials, including bitumens [52], plasticizers [53], tackifiers [54] and processing aids  

the location of the glass transition temperature (Tg), in the range -20 to +35 °C, and the associated major changes in, e.g., modulus for relatively small changes in copolymer styrene content or temperature  

This section provides more details on selected aspects of blend systems using interpolymers as components, filler composites and terpolymers. A related aspect which warrants mention in relation to multicomponent systems is the interfacial nature and behavior of these interpolymers. Ronesi [55] presented a study of the interfacial adhesion between LDPE and ESI, analyzing the significant effects of ESI copolymer styrene content, layer thickness and test temperature. 

As reported by Diehl et al. [58], interpolymers are also compatible with a broader range of polymers, including styrene block copolymers [59], poly(vinyl chloride) (PVC)-based polymers [60], poly(phenylene ethers) [61] and olefinic polymers such as ethylene-acrylic acid copolymer, ethylene-vinyl acetate copolymer and chlorinated polyethylene. Owing to their unique molecular structure, specific ESI have been demonstrated as effective blend compatibilizers for polystyrene-polyethylene blends [62,63]. The development of the miscibility/ compatibility behavior of ESI-ESI blends differing in styrene content will be highlighted below. 

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TABLE 4.2 Chemical Engineering Aspects of Electronic, Photonic, and Recording Materials and Devices... 

Kayabali, K. 1997. Engineering aspects of a novel landfill liner material bentonite-amended natural zeolite. Eng Geology 46 105-114. 

The recent literature in bioelectrochemical technology, covering primarily the electrochemical aspects of enzyme immobilization and mediation, includes few reports describing engineering aspects of enzymatic biofuel cells or related devices. Current engineering efforts address issues of catalytic rate and stability by seeking improved kinetic and thermodynamic properties in modified enzymes or synthesized enzyme mimics. Equally important is the development of materials and electrode structures that fully maximize the reaction rates of known biocatalysts within a stable environment. Ultimately, the performance of biocatalysts can be assessed only by their implementation in practical devices. 

This chapter will exclude all detailed descriptions of physical properties and experimental results presented in several of the Physics journals. The theoretical aspects of superconductivity will also be omitted, as well as the practical application and engineering aspects of these new materials. 

When receiving bulk raw materials, the grade of the material must be carefully checked before it is transferred to any tank. In addition to visual and paper checks, it must be impossible from an engineered aspect to add an isocyanate to a polyol tank or a polyol to an isocyanate tank, as there may be an extremely severe reaction. 

Several studies have examined the thickness of the domain wall in ferroelectric materials [17]. The 90° a-c domain wall thickness has been measured using a transmission electron microscope (tem), [14] but distinguishing the positive and negative domains in 180° opposite polarization areas is difficult because these methods are used to observe the strain of arrangements of molecules. Direct clarification of the domain wall thickness is important with respect to both scientific and engineering aspects. 

Below, we analyze physico-chemical and engineering aspects of formation of microporous materials in processes of pyrolysis. 

This chapter focuses on the catalytic aspects of methanol chemistry and covers thermodynamic, kinetic, chemical engineering, and materials science aspects. It provides brief introductions into these topics with the aim of establishing an overview of the state of the art of methanol chemistry with only a snapshot of the relevant literature. It highlights what the authors think are the most relevant aspects and future challenges for energy-related catalytic reactions of methanol. It is not meant to provide a complete literature overview on methanol synthesis and reforming. 

Nichols, L.E. 1979. Packaging and storage of raw materials. In Monograph on Recombination of Milk and Milk Products. Technology and Engineering Aspects. Document 116, pp. 53-55, International Dairy Federation, Bussels. 

Engineering aspects failures related to the properties of materials or due to anomalies in design or to the improper selection of materials... 

The expanded bed is, in principle, similar to a fluidized bed, a common unit-operation in the chemical industry.3 However, in the expanded-bed method, mixing of the adsorbent material is minimal during the operation, whereas a fluidized bed is turbulent. This means that an expanded bed is more effective for adsorption and elution processes than the fluidized bed. A complete review of all engineering aspects, comparing expanded beds and fluidized beds, can be found in Thommes.4 The expanded-bed adsorption operation is illustrated in Fig. 2. 

This chapter reviews some of the main topics involved in the design and modeling of solar photocatalytic reactors, with particular emphasis on the authors research experience. Solar photons are source of energy that initiates photocatalytic degradation. Thus, proper consideration of radiative processes is key to address this subject. The determination of the directional and spectral characteristics of solar UV radiation, the interaction of the catalyst with radiation inside reaction spaces, the optical design of solar collectors, and the optical properties of the materials involved are all subjects where these concepts are necessary. Therefore, developments in this area should be solidly grounded on the fields of solar collector optics and radiative transfer, besides the more traditional chemical engineering aspects involved. This requires a multidisciplinary approach. 

Hlavacek, V., and Puszynski, J. A., Chemical engineering aspects of advanced ceramic materials. Irul. Eng. Chem. Res., 35,349 (1996). 

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