# Mechanical Performance of Polymer Materials for Low-Temperature Applications
## 3 Results and Discussion
### Application under Low-Temperature Conditions in Ships and Offshore Structures  
Polymer materials are widely used in pipeline systems in marine structures for chemicals, ballast and bunker lines, black and gray water, seawater and freshwater cooling, and  
Figure 8: Strain-rate-dependent stress-strain curves of the polymers at \(-100\)\({}^{\circ}\)C: (**a**) PVDF, (**b**) PE, and (**c**) ABS. hot and cold water. In terms of structural design, various considerations are involved in terms of chemical resistance, impact strength, rigidity, and flexibility for assembly and operating temperature in all building service applications. Among these considerations, in the present study, the mechanical properties of the three polymer materials were evaluated and compared to determine the material specifications for low-temperature conditions. Table 2 presents the comparative results of materials and the tensile strength and Young's modulus from cryogenic- to room-temperature conditions. The tests were performed at a constant strain rate of 1.0 \(\times\) 10\({}^{-3}\)/s. [PERSON] et al. [30] reported that yield stress could be considered for the tensile strength values owing to the characteristics of ductile polymers, and no single point in the material starts to yield. In the present study, as the tests were performed at a low crosshead speed, attention was focused on Young's modulus in accordance with the initial slope of the stress-strain curves. In the test of PVDF, a decrease in temperature from 25 \({}^{\circ}\)C to \(-\)50 and \(-\)100 \({}^{\circ}\)C resulted in a 121% and 252% increase in tensile strength and a 113% and 381% increase, respectively, in Young's modulus. For PE, the decrease in temperature resulted in a 181% and 193% increase in tensile strength and 483% and 750% increase in Young's modulus. With the same method, temperature was found to affect tensile properties in the test of ABS, resulting in a 39% and 92% increase in tensile strength and 20% and 89% increase in Young's modulus with decreasing temperature, at \(-\)50 \({}^{\circ}\)C and \(-\)100 \({}^{\circ}\)C, respectively. Therefore, the mechanical properties of the polymers, i.e., tensile strength and Young's modulus, improved at low temperatures and showed similar tendencies. In addition, PVDF exhibited the best mechanical properties, and PE exhibited the highest increase rate in terms of tensile strength and Young's modulus. Table 3 reveals that the fracture strain and modulus of toughness markedly decrease as the temperature decreases to cryogenic levels. Thus, durability and stability under temperature variation should be considered for application at industrial sites. The fracture strain and modulus of toughness of ABS were considerably lower than those of PVDF and PE both at room and low temperatures. By contrast, in terms of the fracture strain and modulus of toughness, except for the fracture strain of PVDF at 0 \({}^{\circ}\)C, PVDF exhibited the highest value above 0 \({}^{\circ}\)C, followed by PE and ABS. However, the fracture strain of PE was higher than those of PVDF and ABS below 0 \({}^{\circ}\)C, whereas its modulus of toughness was lower than that of PVDF at \(-\)50 \({}^{\circ}\)C. This result implies that these polymers should be considered for application at suitable temperature ranges. In addition, for a clearer understanding of the test results for various polymers, the mechanical properties were plotted in Figure 9. Therefore, it should be considered that these polymers apply to offshore suitable temperature ranges.