Characterization of thermal properties

B. Characterization of Thermal Properties, Crystallinity, and Phase Behavior of Polyanhydrides... 

The most common techniques used for characterization of thermal properties and structure are TGA, DSC, DMA, FT-IR and XRD. Each of these techniques is used to elucidate specific aspects of agro-polymers. 

Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) are the most widely-used techniques for characterization of thermal properties of polymers and composites. 

Thermal Analysis - Differential Scanning Calorimetry (DSC) and thermal gravimetric analysis (TGA) were used to characterize the thermal properties of the polymers synthesized. DSC analysis was performed on a Perkin-Elmer Differential Scanning Calorimeter, Model 2C with a thermal analysis data station. Thermal gravimetric analysis (TGA) was carried out on a DuPont thermal gravimeter, Model 951. From the DSC and TGA plots of poly (N-pheny 1-3,4-dimethylene-... 

It is important to characterize the thermal properties of polyanhydrides that are proposed for drug delivery applications, as changes in crystallinity... 

Section 2.2.1 summarizes the spectroscopic measurements that have been performed to examine the dynamics of water molecules in hydrate versus ice networks. Sections 2.2.2 and 2.2.3 provide a brief overview of the mechanical and thermal properties, respectively, of hydrates compared to ice. Characterization of these properties will aid in facilitating the accurate interpretation of data obtained from in situ detection measurements of natural hydrates. These natural hydrates occur in sediments in permafrost and marine environments. The hydrate mechanical and thermal properties are also important in the evaluation of the location and distribution of natural hydrates in sediments. (Further details are given in Chapter 7—Hydrates in the Earth.)... 

A primary method that is used to characterize the thermal properties of a bulk material is thermogravimetric analysis (TGA). This method provides detailed information regarding the thermal stability and decomposition pathway of a material e.g., stepwise loss of ligands for an organometallic compound), as well as structural information for complex composites (Figure 7.52). The operating principle of TGA is... 

Busi S, Lahtinen M, Mansikkamaki H, et al. Synthesis, characterization and thermal properties of small RiR2 N X -type quaternary ammonium halides. J. Solid State Chem. 2005. 178, 1722-1737. 

Busi S, Lahtinen M, KamaM, Valkonen J, Kolehmainen E, Rissanen K(2006) Synthesis,characterization and thermal properties of nine quaternary dialkyldiartilkylammonium chlorides. J Mol Struct 787 18-30... 

Additional assays may also be conducted on this material to more comprehensively characterize its thermal properties. The following may be considered variable temperature XRD (VT-XRD) studies may be conducted to observe changes in the powder diffraction patterns of the material as a function of temperature. Selection of appropriate temperatures depends on several factors the DSC transition temperatures, corroborating TGA and hot-stage evidence, and the accuracy of the heating controller for the XRD unit. It should also be noted that although XRD data may be collected at several different temperatures to simulate a variable temperature experiment, the follow-up VT-XRD assay is essentially a series of isothermal experiments, and the DSC is a dynamic assay. It is therefore reasonable to expect some variation in transition temperatures. 

Barikani, M., and S. Mehdipour. 1999. Synthesis, characterization and thermal properties of novel arglene sulfure ether polyinides and polyamides. Journal of Polymer... 

Zhang, G.H. Bon, S.A.F Zhao, C.Y. Synthesis, characterization and thermal properties of novel nano-encapsulated phase change materials for thermal energy storage. Sol Energ 86 (2012) 1149-1154. 

Alkan, C. San, A. Karaipekli, A. Uzun, O. Preparation, characterization, and thermal properties of microencapsulated phase change material for thermal energy storage. Sol Energ Mat Sol C 93 (2009) 143-147. 

San, A. Alkan, C. Karaipekli, A. Rreparation, characterization and thermal properties of RMMA/w-heptadecane microcapsules as novel solid-liquid microRCM for thermal energy storage. Appl Energ 87 (2010) 1529-1534. 

Yu, R Chen, Z.-H. Zeng, X.-R. Preparation, characterization and thermal properties of microPCMs containing n-dodecanol by using different types of styrene-maleic anhydride as emulsifier. Colloid Polym Sci 287 (2009) 549-560. 

S. Mallakpour, F. Zeraatpisheh, The nanocomposites of zinc oxide/ 1-amino acid-based chiral poly (ester-imide) via an ultrasonic route synthesis, characterization, and thermal properties, J. Appl. Polym. Sd. 289 (2012) 1055-1064. 

Jayakumar, R., Tamura, T. Synthesis, characterization and thermal properties of chitin- -poly(6-cajnolactone) copolymers by using chitin gel. Int. J. Biol. Macromol. 43, 32—36 (2008)... 

Almost all thermal destruction and incineration problems of today involve multiphase situations. In two-phase flows, accurate size and velocity measurements of particles are important for a broad spectrum of applications. Solid particles are not spherical in shape. Their shape is qnite complex and far from being uniform. Complete characterization of local properties includes such attributes as particle size and number density distribntion, a velocity distribution function related to particles of different size, mean velocity of the gas phase, local gas and particle temperatures, composition of both the gas and particle phases, turbulence properties, and the Uke. In particle-laden flows the influence of turbulence on the particles and vice versa is important. The reUable and precise measurement of any one of the above properties is a nontrivial task. 

Nagendiran, S., Alagar, M., Hamerton, I. Octasilsesquioxane-reinforced DGEBA and TGDDM epoxy nanocomposites Characterization of thermal, dielectric and morphological properties. Acta Mater. 58, 3345-3356 (2010)... 

Wang, R. Fang, L. Xu, C., Synthesis, Characterization, and Thermal Properties of New Silarylene-Siloxane-Acetylene Polymers. Eur. Polym. J. 2010,46, 465-471. 

Table 18.5 Polymerization yields, color, GPC characterization and thermal properties of BBO polymers P38-43.

Ceramographic methods have proven indispensable in the characterization of thermally sprayed coatings, in which non-destructive testing methods for purposes of quality assurance have only limited applicability. Characteristic properties of a coating, such as its thickness, structure, porosity, and adhesion to the base material, as well as the hardness of individual phases or the overall composite, can be accurately evaluated by applying these ceramographic methods to the polished section. 

Experience to date indicates that if there is adequate characterization of material properties (in particular the cure kinetics response) and the HTC boundary conditions, then the prediction of thermal history and consequent degree of cure evolution is sufficient for most practical purposes. Currently, the biggest impediments to further adoption of process simulation for thermal management are materials characterization costs (which are one-off) and cost-effective boundary condition characterization, particularly for the case of process variations and deviations such as random positioning of tools in autoclaves and similar uncontrolled practical issues. 

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