Development and use of plastics

文章大意

讲座梳理20世纪30年代以来塑料的发展，重点讲聚乙烯（LDPE与HDPE）、聚氨酯（发泡与纤维形态）和PET的特性与家庭用途，如包装袋、奶瓶、家具填充、屋顶保温、运动服和碳酸饮料瓶等。

题目与答案

1. 1930s

   Polythene - two main forms:

   ·LDPE - distinguishing feature: it is highly 31_____

   答案：flexible

   原文定位：The first, low-density polyethylene, better known as LDPE, is very flexible, and indeed this is probably its most significant feature

   同义替换：「distinguishing」↔「most significant」，「highly」↔「very」

2. e.g. used to make 32_____ carrier bags and packaging materials

   答案：film

   原文定位：This means that it's suitable for making things like film and also carrier bags and other packaging materials

   同义替换：「used to」↔「suitable for」

3. ·HDPE - made tougher by exposure to a particular kind of 33_____

   suitable for rigid container, e.g. for bleach

   答案：gas

   原文定位：High-density HDPE is more robust, and it can be made more so by exposing it to a type of gas

   同义替换：「made tougher」↔「made more so」，「kind」↔「type」

4. Polyurethane - two main forms:

   ·blown form - used for making 34_____. (padding)

   答案：foam

   原文定位：The first form is known as blown, and this type is used in the manufacture of furniture for the padded parts

   同义替换：「making」↔「manufacture」

5. widely used in housing infrastructure to give 35_____

   ·non-blown form - used mainly for sportswear

   答案：insulation

   原文定位：Blown polyurethane is also still widely used in the infrastructure of houses as a means of providing insulation in loft and roof spaces in particular

   同义替换：「give」↔「providing」

6. 1940s - 1950s

   PET

   - used to make 36_____ e.g. Dacron and Terylene

   答案：fabric

   原文定位：Its first application was in fabric under the brand names of Dacron and Terylene

   同义替换：「used to make」↔「application was in」

7. - popular for making containers for fizzy drinks

   - used for household objects such as 37_____ because it resists abrasion

   答案：trays

   原文定位：PET is also very resistant to abrasion, and for this reason, it is used in the home for trays and other items that are often heavily scratched

   同义替换：「household objects」↔「used in the home for」

8. Tupperware

   ·storage boxes

   ·revolution in 38_____ techniques

   答案：sales

   原文定位：However, what Tupperware is probably best known for is the revolutionary techniques its inventor developed for sales

9. 1960s

   Teflon

   ·non-stick, almost no 39_____

   ·used for protective coatings, e.g. for frying pans

   答案：friction

   原文定位：This is a non-stick material with hardly any friction, which can be deposited on metal surfaces as a protective coating

   同义替换：「almost no」↔「hardly any」

10. Gore-Tex

    ·best known for outdoor wear

    ·also used for various 40_____ purposes

    答案：medical

    原文定位：However, Gore-Tex has other uses which are less well known. It is increasingly being used for making materials used for a variety of medical applications

    同义替换：「various」↔「variety」，「purposes」↔「applications」