1.1 Overview of aerospace industry
Globally, 3.57 billion passengers travelled on aeroplanes during 2015 and the demand for air travel is predicted to keep rising.1 As the frequency of air travel is increasing, it places a pressure on the aerospace industry to improve material performance and the efficiency of their transportation.2 Classically aircraft were constructed from metallic materials such as aluminium and titanium. Therefore, new materials must have specific properties and characteristics that the metallic materials possess, but in addition, present further beneficial properties. Aeronautical materials must possess a high Young’s modulus to prevent shape deformation under stress, high resistance to chemical and thermal degradation, high glass transition temperature (Tg), impact strength, amongst numerous others which are more task specific.3 Advancements in polymer chemistry have resulted in a large number of aircraft moving from metallic materials to composite for their primary structures. The definition of a composite states that it is a new material with superior structural properties, which is formed from two or more materials that differ in physical and mechanical behaviour. …show more content…
The polymer matrix is formed during the curing cycle in which temporary or chemical bonding occurs between polymer chains. Thermoset polymers possess permanent crosslinking whereas thermoplastics undergo temporary intermolecular crosslinking. The intermolecular crosslinks are weak and lead to the entanglement of the polymer chains with dipole-dipole and London dispersion interactions between polymer segments. Thermoset and thermoplastic polymers have advantages and disadvantages to their use, but aeronautical composites are characteristically thermosetting polymer matrices. Possible thermosetting polymers include bismaleimides (BMI),13 benzoxazines,14 but epoxies15 are most commonly
Globally, 3.57 billion passengers travelled on aeroplanes during 2015 and the demand for air travel is predicted to keep rising.1 As the frequency of air travel is increasing, it places a pressure on the aerospace industry to improve material performance and the efficiency of their transportation.2 Classically aircraft were constructed from metallic materials such as aluminium and titanium. Therefore, new materials must have specific properties and characteristics that the metallic materials possess, but in addition, present further beneficial properties. Aeronautical materials must possess a high Young’s modulus to prevent shape deformation under stress, high resistance to chemical and thermal degradation, high glass transition temperature (Tg), impact strength, amongst numerous others which are more task specific.3 Advancements in polymer chemistry have resulted in a large number of aircraft moving from metallic materials to composite for their primary structures. The definition of a composite states that it is a new material with superior structural properties, which is formed from two or more materials that differ in physical and mechanical behaviour. …show more content…
The polymer matrix is formed during the curing cycle in which temporary or chemical bonding occurs between polymer chains. Thermoset polymers possess permanent crosslinking whereas thermoplastics undergo temporary intermolecular crosslinking. The intermolecular crosslinks are weak and lead to the entanglement of the polymer chains with dipole-dipole and London dispersion interactions between polymer segments. Thermoset and thermoplastic polymers have advantages and disadvantages to their use, but aeronautical composites are characteristically thermosetting polymer matrices. Possible thermosetting polymers include bismaleimides (BMI),13 benzoxazines,14 but epoxies15 are most commonly