英语翻译Most conveniently,polymers are generally subdivided in t

英语翻译
Most conveniently,polymers are generally subdivided in three categories,viz.,plastics,rubbers and fibers.In terms of initial elastic modulus,rubbers ranging generally between 10(6) to 10(7) dynes/cm²,represent the lower end of the scale,while fibers with high initial moduli of 10(10) to 10(11) dynes/cm² are situated on the upper end of the scale; plastics,having generally an initial elastic modulus of 10(8) to 10(9) dynes/cm²,lie in-between.As is found in all phases of polymer chemistry,there are many exceptions to this categorization.
An elastomer (or rubber) results from a polymer having relatively weak interchain forces and high molecular weights.When the molecular chains are “straightened out” or stretched by a rocess of extension,they do not have sufficient attraction for each other to maintain the oriented state and will retract once the force is released.This is the basis of elastic behavior.
However,if the interchain forces are very great,a polymer will make a good fiber.Therefore,when the polymer is highly stretched,the oriented chain will come under the influence of the powerful attractive forces and will “crystallize” permanently in a more or less a material of high tensile strength and high initial modulus,i.e.,a fiber.Therefore,a potential fiber polymer will not become a fiber unless subjected to a “drawing” process,i.e.,a process resulting in a high degree of intermolecular orientation.

简单的说,聚合物一般分为三类,塑料、橡胶、纤维.按起始弹性模量分类,橡胶的是10(6) to 10(7) dynes/cm²,弹性最小；纤维 10(10) to 10(11) dynes/cm²,弹性最大；塑料 10(8) to 10(9) dynes/cm²,弹性居中.象所有聚合物化学领域一样,这一分类有许多例外.
由聚合物生成的人造橡胶,其分子链间的作用力较小,而分子量较大.当它的分子链被拉伸时,这些分子链之间没有足够的引力维持被拉伸后的状态,因此当外力消失后就回缩了.这就是弹性原理.
（待续）