What is polymer cross linking?

This is the lecture notes used during youth education camps. The target audience is high school students, although we have coducted this same camp with yout as young as 5th grade. A disclaimer is noted in the slides regarding which artwork is original and free to use, and which few items are not original and should not be re-used without permission.   Unless otherwise noted, all images and cartoons are free to use under the Creative Commons license.本数据集为青少年教育营所用的授课讲义。其目标受众为高中生，但我们也曾面向低至五年级的青少年开展过同类营会。演示文稿中附有免责声明，明确标注了哪些美术作品为原创且可免费使用，以及少量非原创作品未经许可不得重复使用。 除非另有说明，所有图片与漫画均可在知识共享（Creative Commons）许可协议下免费使用。