Thermal properties of polyurethane

Chen H, Lu H, Zhou Y, Zheng M, Ke C, Zeng D (2012) Study on thermal properties of polyurethane nanocomposites based on organo-sepiolite. Polym Degrad Stab 97 242-247... 

Effect of moisture absorption on the thermal properties of polyurethane... 

Yamauchi N, Hirose S, Hatakeyama H (2001) Preparation and thermal properties of polyurethane composite containing fertilizer. In Keimedy JF, Phillips GO, Williams PA, Hattikeyama H (eds) Recent advances in environmentally compatible polymers. Woodhead, Ctimbridge, pp 211-216... 

The current method of determining the energy properties of polyurethane is the Dynamic Thermal Mechanical Analyzer (DTMA). This instrument applies a cyclic stress/strain to a sample of polyurethane in a tension, compression, or twisting mode. The frequency of application can be adjusted. The sample is maintained in a temperature-controlled environment. The temperature is ramped up over the desired temperature range. The storage modulus of the polyurethane can be determined over the whole range of temperatures. Another important property closely related to the resilience, namely tan delta (8), can also be obtained. Tan (8) is defined in the simplest terms as the viscous modulus divided by the elastic modulus. 

Table II. Thermal and Mechanical Properties of Polyurethanes Based on PTHF629 Diols, Monoglucosides, and Bisglucosides...

The low thermal conductivity of polyurethanes, plus the ease of application and structural properties of foamed-in-place materials, affords great freedom of design. As a result, rigid polyurethane foams have displaced rock wool and glass wool in freezers and refrigerators. 

J Nakano, Y Izuta, T Orita, H Hatakeyama, K Kobashigawa, K Teruya, S Hirose. Thermal and mechanical properties of polyurethanes derived from fractionated kraft lignin. Sen-I Gakkaishi 53 416 22, 1997. 

Dynamic Mechanical and Thermal Properties of Seven Polyurethane Adhesives... 

As a consequence of the outstanding properties of polyurethane as a porous material and therefore for synthesis of membranes, research continues focused not only on environmental fields but also in diverse areas such as medical devices or adhesives. Therefore, there is a potential area to develop polyurethane-separation materials as membranes. The use of naturally based polyurethane monomers during synthesis reactions [polyol, isocyanates, and chain extenders), are also key factors to explore in future to control morphological, mechanical, and thermal desirable properties. In addition the modification of polyurethane with potential natural absorbent biopolymers is an emergent research line that has demonstrated successful results [9,81,82]. 

Bak Bakar, M., Skrzypek, K. Effect of kaolin and polyurethane on the fracture and thermal properties of epoxy based compositions. Mater. Sci. 13 (2007) 39—42. 

INVESTIGATIONS ON THE THERMAL PROPERTIES OF RIGID POLYURETHANE FOAMS. 

Chattopadhyay, D. K., Aswini, K., Mishra, B., Sreedhar, K., and Raju, K. V. Thermal and Viscoelastic Properties of Polyurethane-Imide/Clay Hybrid Coatings. Polymer Degradation and Stability, 91, 1837-1849 (2006). 

H. Liu, L. Zhang, J. Li, D. Hauang, Y. Wang and Y. Li, Mechanical and thermal properties of nano-hydroxyapatite/polyurethane composites , Acta Materiae Compositae Sinica, 2010-03. 

A. M. (2013) Thermal, mechanical and electroactive shape memory properties of polyurethane (PU)/poly(lactic acid)(PLA)/CNT nanocomposites. Eur. Polyrtu /., 49 (11), 3492-3500. 

Chen, S., Wang, Q., Wang, T., Pei, X. Preparation, damping and thermal properties of potassium tltanate whiskers filled castor oil-based polyurethane/epoxy Interpenetrating polymer network composites. Mater. Des. 32, 803-807 (2011)... 

The way in which the chemical structure of the various chain extenders of Table 3.16 influences the thermal stability of polyurethane elastomers based on the molecule Capa 225/CHDI/chain extender in the molar ratio 1 2 1, respectively, is given in the following figures and tables. For example, Fig. 3.7 shows the dynamic mechanical thermal properties of a series of the polyurethane elastomers in which the variable is the chain extender. The temperature at which the value of the storage modulus (log E ) changes significantly is considered to indicate the limit of thermal stability of the polyurethane elastomers. 

It is possible to use differential thermal analysis (DTA) and thermogravi-metric analysis (TGA) to evaluate the thermal properties of several types of polyurethane elastomers. For example, a typical elastomer prepared from MDI, a polyether and an aliphatic diamine extender will show from DTA two very small endothermic changes, one at 150°C and one at 205°C that is identical with the softening temperature. The polymer is found to melt at 2WC and exhibit weight loss in two steps, respectively, beginning at 280°C and 325X. 

K. C. Frisch, D. Klempner, S. K. Mukherjee, and H. L. Frisch, Stress-Strain Properties and Thermal Resistance of Polyurethane-Polyepoxide, Interpenetrating Polymer Networks, J. Appl. Polym. Sci. 18(3), 689 (1974). Polyurethane/Epoxy SIN. Tensile strength. Heat resistance. 

In addition to thermal and mechanical measurements, several other methods have been used to determine the extent and nature of phase segregation and its effect on the properties of polyurethanes. These methods include birefringence light scattering electron and optical... 

It has been well established by Cooper and Tobolsky that the unique properties of polyurethanes are strongly linked to its two-phase morphology [21], Characterization of microphase separation is performed using a variety of techniques including dynamic mechanical thermal analysis (DMTA), Fourier transform infrared spectroscopy (FTIR), small-angle X-ray scattering (SAXS), and atomic force microscopy. Consideration of both the thermodynamic driving forces and the kinetics is needed to elucidate microstructure formation in polyurethanes [60-66],... 

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