Read the text and decide if the sentences are true (T) or false (F)
Text № 11
Plastic is a material consisting of any of a wide range of synthetic or semi-synthetic organics that are malleable and can be molded into solid objects of diverse shapes. Plastics are typically organic polymers of high molecular mass, but they often contain other substances. They are usually synthetic, most commonly derived from petrochemicals, but many are partially natural.[2] Plasticity is the general property of all materials that are able to irreversibly deform without breaking, but this occurs to such a degree with this class of moldable polymers that their name is an emphasis on this ability.Due to their relatively low cost, ease of manufacture, versatility, and imperviousness to water, plastics are used in an enormous and expanding range of products, from paper clips to spaceships. They have already displaced many traditional materials, such as wood, stone, horn and bone, leather, paper, metal, glass, and ceramic, in most of their former uses. In developed countries, about a third of plastic is used in packaging and another third in buildings such as piping used in plumbing or vinyl siding.
Read the text and decide if the sentences are true (T) or false (F)
Text № 12
Other uses of plastic include automobiles (up to 20% plastic), furniture, and toys. In the developing world, the ratios may be different - for example, reportedly 42% of India's consumption is used in packaging. Plastics have many uses in the medical field as well, to include polymer implants, however the field of plastic surgery is not named for use of plastic material, but rather the more generic meaning of the word plasticity in regards to the reshaping of flesh.
The world's first fully synthetic plastic was invented in New York in 1907 by Leo Baekeland who coined the term 'plastics'. Many chemists contributed to the materials science of plastics, including Nobel laureate Hermann Staudinger who has been called "the father of polymer chemistry" and Herman Mark, known as "the father of polymer physics". Toward the end of the century, one approach to this problem was met with wide efforts toward recycling.
Read the text and decide if the sentences are true (T) or false (F)
Text № 13
There are two types of plastics: thermoplastics and thermosetting polymers. Thermoplastics are the plastics that do not undergo chemical change in their composition when heated and can be molded again and again. Examples include polyethylene, polypropylene, polystyrene and polyvinyl chloride. Common thermoplastics range from 20,000 to 500,000 amu, while thermosets are assumed to have infinite molecular weight. These chains are made up of many repeating molecular units, known as repeat units, derived from monomers; each polymer chain will have several thousand repeating units. Thermosets can melt and take shape once; after they have solidified, they stay solid. In the thermosetting process, a chemical reaction occurs that is irreversible. The vulcanization of rubber is a thermosetting process. Before heating with sulfur, the polyisoprene is a tacky, slightly runny material, but after vulcanization the product is rigid and non-tacky.
|
|
|
Read the text and decide if the sentences are true (T) or false (F)
Text № 14
Interior design is "the art or process of designing the interior decoration of a room or building". An interior designer is someone who coordinates and manages such projects. Interior design is a multifaceted profession that includes conceptual development, communicating with the stakeholders of a project and the management and execution of the design. In the past, interiors were put together instinctively as a part of the process of building. The profession of interior design has been a consequence of the development of society and the complex architecture that has resulted from the development of industrial processes. The pursuit of effective use of space, user well-being and functional design has contributed to the development of the contemporary interior design profession.In ancient India, architects used to work as interior designers. This can be seen from the references of Vishwakarma the architect - one of the gods in Indian mythology. Additionally, the sculptures depicting ancient texts and events are seen in palaces built in 17th century India.
Дата добавления: 2018-06-01; просмотров: 399; Мы поможем в написании вашей работы! |
Мы поможем в написании ваших работ!