Answer: 19th century
Step-by-step explanation:
Plastic was invented by Alexander Parkes in Birmingham, England, with the name "Parkesin", a mixture of nitrocellulose, camphor and alcohol. At that time, rubber was used for materials to be shaped with molds instead of plastic. Parkes showed his invention to the world in 1862 at the Great International Fair. His invention won a bronze medal. Due to the high cost of rubber, Alexander Parkes' invention attracted great attention.
Possibly the largest number of different polymeric materials come under the plastic classification. Plastics are materials that have some structural rigidity under load, and are used in general-purpose applications.Polyethylene, polypropylene, poly(vinyl chloride), polystyrene, and the fluorocarbons, epoxies, phenolics, and polyesters may all be classified as plastics. They have a wide variety of combinations of properties.
Some plastics are very rigid and brittle (Figure 15.1, curve A). Others are flexible, exhibiting both elastic and plastic deformations when stressed, and sometimes experiencing considerable deformation before fractureThere are many different polymeric materials that are familiar to us and find a wide variety of applications; in fact, one way of classifying them is according to their enduse.