Polymer engineering
1907 L. Baekeland reported the synthesis of the first thermosetting phenolic resin, which was industrialized in the 1920s, the first synthetic plastic product.
[3] In 1920, H. Standinger proposed that polymers are long-chain molecules that are connected by structural units through common covalent bonds.
In the 1950s, K. Ziegler and G. Natta discovered a coordination polymerization catalyst and pioneered the era of synthesis of stereoregular polymers.
The basic division of polymers into thermoplastics, elastomers and thermosets helps define their areas of application.
They include polyethylene, polypropylene, nylon, acetal resin, polycarbonate and PET, all of which are widely used materials.
Elastomers are polymers which have very low moduli and show reversible extension when strained, a valuable property for vibration absorption and damping.
It is liquid in the early stage of the manufacturing or molding process, and it is insoluble and infusible after curing, and it cannot be melted or softened again.
It is made up of synthetic resins and fillers, plasticizers, stabilizers, lubricants, colorants and other additives.
The term resin was originally named for the secretion of oil from plants and animals, such as rosin and shellac.
The basic properties of plastics are mainly determined by the nature of the resin, but additives also play an important role.
Rubber is a completely amorphous polymer with a low glass transition temperature and a large molecular weight, often greater than several hundred thousand.
[10] Typical uses of composites are monocoque structures for aerospace and automobiles, as well as more mundane products like fishing rods and bicycles.
On the other hand, some products such as drive shafts, helicopter rotor blades, and propellers look identical to metal precursors owing to the basic functional needs of such components.
Biodegradable polymers also offer great potential for wound management, orthopaedic devices, dental applications and tissue engineering.
Polylactates (PLAs) are popular for drug delivery system due to their fast and adjustable degradation rate.
