Thermal properties of polymers

Applications of polymers, which rely on good thermal properties are listed in Table 3.1. Important thermal properties of polymers are shown in Table 3.2. 

Crosslinked PE Heat resistant housings and heat shrinkable tubing 

PBT (45% mineral and glass fibre) Heating appliances and oven grills 

PEI Microwave oven parts, high temperature switchgear 

PPS (40% glass fibres) High heat resistant applications 

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We use differential scanning calorimetry - which we invariably shorten to DSC - to analyze the thermal properties of polymer samples as a function of temperature. We encapsulate a small sample of polymer, typically weighing a few milligrams, in an aluminum pan that we place on top of a small heater within an insulated cell. We place an empty sample pan atop the heater of an identical reference cell. The temperature of the two cells is ramped at a precise rate and the difference in heat required to maintain the two cells at the same temperature is recorded. A computer provides the results as a thermogram, in which heat flow is plotted as a function of temperature, a schematic example of which is shown in Fig. 7.13. 

The addition of specific nanomaterials can result in significant changes and improvements in thermal properties of polymer composites. In the next section we review some of the principal thermal properties that are affected by introducing nanomaterials in polymer matrices in order to form composites. 

The thermal properties of polymers include their behavior during heating from the solid amorphous (glassy) or crystalline to the liquid (molten) state, but also their chemical and mechanical stability in the entire range of application. 

In the present study, PU s containing lignin were investigated with reference to thermal stability, which is one of the basic thermal properties of polymers. Thermal degradation of PU s which were obtained from solvolysis lignin was studied using thermogravimetry (TG). The inflammability of... 

Chapters 3 and 4 respectively. A good review of methods for the examination of thermal properties of polymers is provided by Thompson (1989). 

Typical values of thermal properties for selected polymers are shown in Table 6.1 [7, 17]. For comparison, the properties for stainless steel are also shown at the end of the list. It should be pointed out that the material properties of polymers are not constant and may vary with temperature, pressure or phase changes. This section will discuss each of these properties individually and present examples of some of the most widely used polymers and measurement techniques. For a more in-depth study of thermal properties of polymers the reader is encouraged to consult the literature [24,46, 66],... 

S. Curgul et al Molecular dynamics simulation of size-dependent structural and thermal properties of polymer nanofiber. Macromolecules 40, 8483-8489 (2007)... 

Flaming combustion of polymeric materials inevitably involves liberation of gaseous fuels. No wonder, therefore, that the interest in the thermal properties of polymers and the mechanisms and kinetics of polymer decomposition and gasification has been high. 

Hobbs CB. Thermal Properties of Polymers Part 1 Industrial Guide to Measurement by Differential Scanning Calorimetry (DSC), (http //midas.npl.co.uk/midas/content/nm058.html)... 

Analytical pyrolysis has a number of characteristics that can make it a very powerful tool in the study of polymers and composite materials. The technique usually requires little sample and can be set with very low limits of detection for a number of analytes. For Py-GC/MS the identification capability of volatile pyrolysate components is exceptionally good. A range of information can be obtained using this technique, including results for polymer identification, polymer structure, thermal properties of polymers, identification of polymer additives, and for the generation of potentially harmful small molecules from polymer decomposition. In most cases of analysis of a polymer or composite material, the technique does not require any sample preparation, not even solubilization of the sample, which may be a difficult task for the type of materials analyzed. The analysis can be easily automated and does not require expensive instrumentation (beyond the cost of the instrument used for pyrolysate analysis). 

The thermal properties of polymers are important for many applications. Therefore, direct probing of polymers on the micro- and nanoscale may provide important insight for the practitioner. One can differentiate several thermal options for AFM visualization of dynamic processes and quantification of thermal properties and transitions. While heatable probes that offer nanoscale resolution have only recently become available,2 temperature control stages are available in many commercial devices. However, simple devices can also be built according to the requirements. In the most common set-ups, the sample is heated from below by some heating device. 

Caruthers, J. M. (ed.). Handbook of Diffusion and Thermal Properties of Polymers and Polymer Solutions, AIChE, New York, 1998. 

Furthermore, in addition to the bulk thermal properties of polymers and resists, determination of Tg of film interfaces and of ultrathin films has become an important issue in thin film imaging (bilayer, 157 nm, and EUV). Various techniques have been employed, which include ellipsometry [481,482], positron annihilation spectroscopy (PALS) [483], QCM [484], scanning viscoelasticity microscope (SVM) [485],x-ray reflectivity [486,487], and thermal probe [488]. 

Hands D. 1977. The thermal properties of polymers. Rubber Chem. Technol. 50 480-522. 

The basic principles for the transport of macromolecules in dilute solution will be discussed in this section these principles will be utilized for molar mass determinations in Section 9. In addition, the viscosities of melts and concentrated solutions will also be treated, but the determination of molar masses by relative viscosities will not be treated here, but in Section 9. It is also more appropriate to treat heat conduction with the thermal properties of polymers in Section 10. 

Mechanical/Thermal Properties of Polymers 334 20.3.3.2 Surface Area Measurement 341... 

Jafari SH, Asadinezhad A, Yavari A, Khonakdar HA, Bbhme F (2005) Compatibilizing effects on the phase morphology and thermal properties of polymer blends based on PTT and m-LLDPE. Polym Bull 54 417-426... 

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