塑料的家族十分庞大。按化学组成可分为有机高分子、无机高分子和元素高分子塑料三大类;按使用范围可分为工程塑料和通用塑料两大类;按热性能可分为热塑性塑料和热固性塑料两大类。下面,我们按第三种分类方法,来介绍一下塑料家族的成员。一热塑性塑料热塑性塑料的特点是:随着温度的升高而变软,随着温度的降低而变硬。这个过程可以反复进行多次。其 Plastic family is very large. According to the chemical composition can be divided into organic polymer, inorganic polymer and elemental polymer plastic three categories; according to the scope of use can be divided into two major categories of engineering plastics and general-purpose plastics; according to the thermal properties can be divided into two major thermoplastics and thermosetting plastics class. Next, we introduce a third class of methods to introduce the members of the plastic family. A thermoplastic thermoplastics feature: softens as the temperature increases and hardens as the temperature decreases. This process can be repeated many times. its