20世纪初期人们利用的天然树脂主要是(?)玛树脂、(?)树脂和紫胶等。随着需要的增加和树脂化学的发展,由松香制成了许多产品。松香有良好的硬度和光泽,但对酸、碱和水的抵抗力不强。为克服上述缺点,制成了一系列松香再加工产品如松香酯、改性酚醛树脂、马来松香和松香醇酸树脂等。松香的反应性完全取决于所含的枞酸,但目前尚没有一种合适的方法来测定松香中的枞酸。本文作者研究制定了一种快速(反应时间15分钟)、方便(可在一般实验室条件下 The natural resins that people used in the early 20th century were mainly (?) Ma resin, (?) Resin and shellac. As the need arises and the development of resin chemistry, many products are made from rosin. Rosin has a good hardness and gloss, but the acid, alkali and water resistance is not strong. To overcome these shortcomings, a series of rosin re-processed products such as rosin ester, modified phenolic resin, malay rosin and rosin alkyd resin were made. Rosin reactivity depends entirely on the contained abietic acid, but there is no suitable method to determine abietic acid in rosin. The author of the study developed a fast (reaction time 15 minutes), convenient (in general laboratory conditions