I need help answering this question, please To select a material for an application, it is necessary to evaluate whether its chemical and mechanical structure can be applied to a specific function and whether its properties will meet the required demands of the applied product. One way to identify these characteristics is to understand the types of deformations that materials can undergo. Describe the differences between elastic deformation and plastic deformation in polymers, and how these concepts influence the mechanical properties of polymeric materials. Then, provide examples of practical situations where each type of deformation can be observed.

What are the two micro-scale plasticity mechanisms active in amorphous polymers? Are they likely to occur simultaneously? Explain.

Engineering materials plays an important role in manufacturing industry for the development of products for high performance applications. Describe the main classifications of engineering materials and give details of physical and mechanical properties of three materials for each category.

Consider an aircraft powered by a turbojet engine that has a pressure ratio of 9. The aircraft is stationary on the ground, held in position by its brakes. The ambient air is at 7°C and 95 kPa and enters the engine at a rate of 20 kg/s. The jet fuel has a heating value of 42,700 kJ/kg, and it is burned completely at a rate of 0.5 kg/s.

Given the table below and your judgement for extreme operational conditions, select polymers for the following applications respectively: a dry ice bucket (operating temperature of -78C), a teeth aligner, a hair dryer (operating temperature range of 60-80C) and a phone case. Table 15.2 Melting and Glass Transition Temperatures for Some of the More Common Polymeric Materials Material Polyethylene (low density) Polytetrafluoroethylene Polyethylene (high density) Polypropylene Nylon 6,6 Polyester (PET) Poly(vinyl chloride) Polystyrene Polycarbonate U Glass Transition Temperature [°C (°F)] -110 (-165) -97 (-140) -90 (-130) -18 (0) 57 (135) 69 (155) 87 (190) 100 (212) 150 (300) a. b. c. Nylon, PET, HDPE, PVC Dd. HDP , LDPE, LDPE, PTFE e. LDPE, PTFE, Nylon, polypropylene Melting Temperature [°C (°F)] 115 (240) 327 (620) 137 (279) 175 (347) 265 (510) 265 (510) 212 (415) 240 (465) 265 (510) PTFE, HDPE, HDPE, polypropylene Polypropylene, PET, PTFE, Polypropylene