At the end of reaction, besides methylenation reaction, there still exists a decomposition reaction of the ether linkage, and a little amount of ether linkage still occurs after the end of reaction.

• 在树脂的缩聚阶段除了有亚甲基化的反应外，还存在着醚键的分解反应，少量的醚健在反应结束后仍然存在。