本研究探討利用甲殼質化學改質廢輪胎經熱裂解後之炭質物，藉以改變炭質物表面結構與化學活性，使之活化成有用碳黑。利用酸減法處理國內由廢胎經 大氣熱裂解條件下所得炭質物之灰份及表面化學變化。 The surface acidic functional groups of chars by pyrolysis of used tires, at atmospheric was used . Char obtained under vacuum has the highest amount of acidic groups, while char obtained at atmospheric pressure has similar surface and carboxyl content after extraction with toluene for eight hours. Char contains higher ash than that of commercial black. This study try to use Chitin to modify the surface of the char. After treating, the surface and the total acid content of the char was reducing till a plateau was reached. The optimum content of the chitin was determined at 0.2 gram.