fastness , transparency , ease of processing , etc. , and although they also have their limitations , their exploitation is limited only by the ingenuity of the designer.

现代社会没有塑料真是难以想象。今天它们是组成每个人生活的必备部分，从不断变化的平凡物品到尖端科技的医学仪器。当今的设计师和工程师已开始着手塑料的研究，因为它们提供了不能应用于任何其它材料的综合性能。塑料所呈现的优点诸如质轻、弹性、防腐、不易褪色、透明性、易于加工等等，尽管也有它们的制约，它们的开发仅因设计师的创造力受到限制。

It is usual to think that plastics are a relatively recent development but in fact, as part of the larger family called “polymers”, they are a basic ingredient of plant and animal life. Polymers are materials which consist of very long chain-like molecules. Natural materials such as silk, shellac, bitumen, rubber and cellulose have this type of structure. However, it was not until the 19 century that attempts were made to develop a synthetic polymeric material and the first success was based on cellulose. This was a material called “Parkesine”, after its inventor Alexander Parkes, and although it was not a commercial success it was a start and eventually led to the development of “Celluoid”. This material was an important break-through because it became established as a good replacement of natural materials which were in short supply .

通常认为塑料是一种相对新的发展，但事实上作为 “聚合物”大家族的成员，它们是动植物生活的一个基本组成部分。聚合物是由象链一样非常长的分子组成的材料。象丝、虫胶、沥青、橡胶和纤维素之类的天然材料有这种类型的结构。然而，直到19世纪才尝试开发了一种合成聚合物材料，首次成功基于赛璐珞。这是一种叫做“硝化纤维素塑料”的材料，它的发明者是Alexander Parkes ,尽管不是一种开始的商业成功，最终导致了“赛璐珞”的发展。这种材料是一个重要的突破因为它成为了供应短缺的天然材料的良好替代品。

During the early twentieth century there was considerable interest in these new synthetic materials. Phenol-formaldehyde (“bakelite”) was introduced in 1905 and about the time of the second World War materials such as nylon, polyethylene and acrylic (“Perspex”) appeared on the scene. Unfortunately many of the early applications for plastics earned them a reputation as being cheap substitutes. th