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Ielts Reading TEST 1 - rshhhhrhrr
Course: english 101 (Eng101)
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University: University of Shendi
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READING TEST 1 2020
FOR MORE READING TEST VISIT WWW.IELTSCUECARD.TRENDINGGYAN.COM
SECTION 1 BAKELITE
In 1907, Leo Hendrick Baekeland, a Belgian scientist working in New York, discovered and patented a
revolutionary new synthetic material. His invention, which he named ‘Bakelite’, was of enormous
technological importance, and effectively launched the modern plastics industry.
The term ‘plastic’ comes from the Greek plassein, meaning ‘to mould’. Some plastics are derived from
natural sources, some are semi-synthetic (the result of chemical action on a natural substance), and
some are entirely synthetic, that is, chemically engineered from the constituents of coal or oil. Some are
‘thermoplastic’, which means that, like candlewax, they melt when heated and can then be reshaped.
Others are ‘thermosetting’: like eggs, they cannot revert to their original viscous state, and their shape is
thus fixed forever. Bakelite had the distinction of being the first totally synthetic thermosetting plastic.
The history of today’s plastics begins with the discovery of a series of semi-synthetic thermoplastic
materials in the mid-nineteenth century. The impetus behind the development of these early plastics
was generated by a number of factors – immense technological progress in the domain of chemistry,
coupled with wider cultural changes, and the pragmatic need to find acceptable substitutes for
dwindling supplies of ‘luxury’ materials such as tortoiseshell and ivory.
Baekeland’s interest in plastics began in 1885 when, as a young chemistry student in Belgium, he
embarked on research into phenolic resins, the group of sticky substances produced when phenol
(carbolic acid) combines with an aldehyde (a volatile fluid similar to alcohol). He soon abandoned the
subject, however, only returning to it some years later. By 1905 he was a wealthy New Yorker, having
recently made his fortune with the invention of a new photographic paper. While Baekeland had been
busily amassing dollars, some advances had been made in the development of plastics. The years 1899
and 1900 had seen the patenting of the first semi-synthetic thermosetting material that could be
manufactured on an industrial scale. In purely scientific terms, Baekeland’s major contribution to the
field is not so much the actual discovery of the material to which he gave his name, but rather the
method by which a reaction between phenol and formaldehyde could be controlled, thus making
possible its preparation on a commercial basis. On 13 July 1907, Baekeland took out his famous patent
describing this preparation, the essential features of which are still in use today.
The original patent outlined a three-stage process, in which phenol and formaldehyde (from wood or
coal) were initially combined under vacuum inside a large egg-shaped kettle. The result was a resin
known as Novalak, which became soluble and malleable when heated. The resin was allowed to cool in
shallow trays until it hardened, and then broken up and ground into powder. Other substances were
then introduced: including fillers, such as woodflour, asbestos or cotton, which increase strength and
moisture resistance, catalysts (substances to speed up the reaction between two chemicals without
joining to either) and hexa, a compound of ammonia and formaldehyde which supplied the additional
formaldehyde necessary to form a thermosetting resin. This resin was then left to cool and harden, and