作业帮polymer spherulites 的英文解释是什么?
来源：学生作业帮 编辑：作业帮 分类：英语作业 时间：2024/07/17 11:42:38
polymer spherulites 的英文解释是什么?
我的意思 是 用一段英文解释上述词的意思
我的意思 是 用一段英文解释上述词的意思
spherulites (from Greek sphaira = ball and lithos = stone) are spherical semicrystalline regions inside non-branched linear polymers.Their formation is associated with crystallization of polymers from the melt and is controlled by several parameters such as the number of nucleation sites,structure of the polymer molecules,cooling rate,etc.Depending on those parameters,spherulite diameter may vary in a wide range from a few micrometers to millimeters.Spherulites are composed of highly ordered lamellae,which result in higher density,hardness,but also brittleness of the spherulites as compared to disordered polymer.The lamellae are connected by amorphous regions which provide certain elasticity and impact resistance.Alignment of the polymer molecules within the lamellae results in birefringence producing a variety of colored patterns,including Maltese cross,when spherulites are viewed between crossed polarizers in an optical microscope.